Дисертації: "PHSA"

1

Chavan, Sayali Ramdas. "Development, modeling and optimization of CO2 separation process using membrane contactor : applied to hydrogen purification." Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPAST040.

Повний текст джерела

Анотація:

Ce travail est consacré à la séparation du CO2 d'un syngas pour produire de l'hydrogène de haute pureté par contacteurs membranaires. Le pilote construit au laboratoire utilise des contacteurs à fibres creuses (HFMC). Un premier jeu de données montre que la pureté reste sous le seuil de 99%. Un modèle théorique d'équilibre a permis d'expliquer cela par les concentrations résiduelles de carbonate CO2/3− et de bicarbonate HCO3−. Cela a permis de proposer une nouvelle approche reposant sur la variation du pH (pHSA). Elle atteint une pureté de H2 de 99,96 % et un rendement de 94 %. Un modèle prédictif de transferts a été résolu en 1D, pour une absorption de CO2 pur puis pour un mélange gazeux. Dans les deux cas, les paramètres ont été ajustés puis validés sur des données expérimentales. Ce travail ouvre des perspectives pour une solution compétitive en coûts d'investissement et d'exploitation. Le modèle numérique développé est un puissant outil de conception et d'optimisation
This work focuses on separating CO2 from syngas to produce high purity hydrogen based on gas-liquid absorption. To do so, a lab-scale pilot was built featuring three Hollow Fiber Membrane Contactors (HFMC). Primary sensitivity analysis of the process revealed that the purity remains below 99%, explained by the residual concentrations of carbonate CO2/3− and bicarbonate HCO3−. A theoretical equilibrium model and later a new approach based on pH variation (pHSA) was put forward to overcome the purity limitation achieving H2 purity of 99.96% and 94% yield. Moreover, a predictive transfer model was solved in 1D to predict absorption of CO2 in pure and gas mixtures. The model was fitted for both cases and then validated with experimental data. This work opens perspectives as a competitive solution in terms of investment and operating costs. The numerical model developed is a powerful design and optimization tool

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Reese, Michele. "Following Phia /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9998505.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Henriques, Rita da Silveira. "Perturbação de hiperactividade com défice de atenção." Master's thesis, Universidade da Beira Interior, 2011. http://hdl.handle.net/10400.6/945.

Повний текст джерела

Анотація:

Introdução: A Perturbação de Hiperactividade com Défice de Atenção (PHDA) é um dos distúrbios comportamentais mais frequentes em crianças em idade escolar, tendo apresentado um aumento significativo da sua taxa de prevalência na última década. Afecta de forma significativa o rendimento da criança em vários domínios da sua vida quotidiana, sendo frequentemente acompanhada por uma série de comorbilidades, que influenciam de forma negativa o prognóstico desta patologia. Os défices psicomotores encontrados em grande parte destas crianças, estão associados, em muitos casos, a dificuldades de aprendizagem que se revelam de forma marcante no meio escolar. Objectivos: Este estudo pretende caracterizar a população de crianças com PHDA seguidas no Serviço de Pedopsiquiatria do Centro Hospitalar Cova da Beira (CHCB), na valência de psicomotricidade, bem como identificar o seu perfil psicomotor. Pretende-se, ainda, reconhecer as alterações mais frequentes ao nível dos diferentes factores psicomotores avaliados na Bateria Psicomotora (BPM) de Vítor da Fonseca e verificar a influência da terapia psicomotora na evolução desses défices. Materiais e Métodos: Foram recolhidos os dados referentes à aplicação da BPM em 41 crianças, com idades compreendidas entre os 6 e os 12 anos de idade, com o diagnóstico clínico de PHDA, sendo que 21 dessas crianças foram sujeitas a terapia psicomotora e a uma segunda avaliação através da BPM. Foram analisados os dados correspondentes aos dois períodos de avaliação. Resultados: Os resultados mostraram que embora a maioria das crianças avaliadas apresente um perfil psicomotor normal ou bom, existem alguns défices particulares quando são analisados separadamente os diferentes factores psicomotores, tal como se pode verificar no caso da equilibração, estruturação espácio-temporal e praxia global. Por outro lado, existe uma relação significativa entre a idade, a fase de aprendizagem (ano de escolaridade) da criança e os resultados obtidos na BPM. A terapia psicomotora esteve associada a melhorias significativas no perfil psicomotor. Conclusão: De um modo geral, este estudo apoia a aplicação da BPM no estudo dos défices psicomotores em crianças com dificuldades de aprendizagem e PHDA. A evolução verificada após intervenção psicomotora, quer nas pontuações totais, quer nalguns factores psicomotores em particular, serve de suporte ao seu uso terapêutico neste tipo de crianças.
Introduction: Attention–deficit/hyperactivity disorder (ADHD) is one of the most common behavioural disorders in school age children. We verified a significant increase of the prevalence rate in the last decade. ADHD has many comorbidities affecting the life of the child in every domain with a negative influence in the prognosis of this condition. Psychomotor deficits are responsible for many of the learning disabilities of these children. Goals: This study pretends to characterize the population of children with ADHD followed in the Department of Child Psychiatry of the Centro Hospitalar Cova da Beira (CHCB), under psychomotor therapy. We also pretend to identify the most frequent changes on the different factors evaluated by Psychomotor Battery (BPM) of Vítor da Fonseca and the influence of psychomotor therapy. Materials and Methods: We applied BPM in a sample of 41 children aged between 6 and 12 years old, with the diagnosis of ADHD. 21 of these children were on psychomotor therapy. The data was collected at baseline and at the end of the intervention. Results: The results showed that most of the children had a normal or good psychomotor profile. However there are some impairments when analysing the psychomotor factors one by one. There is a relationship between age, stage of learning (school year) and the results in BPM. Psychomotor profile had a significant improvement after psychomotor therapy. Conclusion: Overall, this study supports the use of BPM in the evaluation of psychomotor deficits in children with learning disabilities and ADHD. The improvements seen after psychomotor intervention, both in global scores or in some factors in particular, support its therapeutic use in such children.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Johnson, Emma Caroline. "Characterisation of PHYA mutants of Arabidopsis thaliana." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/35317.

Повний текст джерела

Анотація:

Phytochrome, a R/FR reversible photoreceptor that regulates plant photomorphogenesis, is encoded by a gene family of which there are at least five members. The best characterised member is phytochrome A which accumulates to high levels in etiolated tissue but is degraded in light, unlike other members of the family which are light-stable. A two-stage screen was designed for isolation of phyA mutant seedlings. The mutant phenotype was illustrated by deficiency in FR-HIR-mediated inhibition of hypocotyl elongation, which is exclusively mediated by phytochrome A while retaining R-HIR-mediated inhibition of hypocotyl elongation, which is mediated by one or more of the light-stable phytochrome species. Mutants isolated using this screen were divided into three complementation classes, fhy1, fhy2 and fhy3. Immunoblot and spectrophotometric analyses of these three mutant lines demonstrated that one of them, fhy2, was deficient in phytochrome A protein. Southern analysis of several alleles of the fhy2 mutation indicated that deficiency in phytochrome A resulted from structural alterations in the PHYA gene. Subsequently, the fhy2 mutants were designated as phyA mutants. The other two classes of long hypocotyl mutants isolated in this screen, fhy1 and fhy3, showed no structural alteration in the PHYA gene and had normal immunochemically and spectrophotometrically detectable levels of phytochrome A. Therefore, fhy1 and fhy3 are putative transduction chain mutants. Comparison of the photophysiology of phytochrome A mutants with that of wild-type seedlings allowed conclusions to be drawn about the roles of phytochrome A in selected, assayable photomorphogenetic responses. phyA mutant seeds exhibit wild-type germination responses to R but do not germinate in FR, suggesting that phytochrome A mediates a promotory response to FR. The importance of phytochrome A as the principal photoreceptor in FR is extended to de-etiolated plants where phytochrome A retains an inhibitory role in hypocotyl elongation, under supplementary FR or low R:FR ratio conditions. Phytochrome A also plays a role in flowering which becomes apparent under low fluence-rate incandescent day extensions, suggesting that in fluence-rate limiting conditions, phytochrome A is an important component of daylength perception. fhy1 and fhy3 mutants, selected for long hypocotyls in FR alongside phyA mutants, were also characterised and shown to have wild-type levels of phytochrome A protein with no apparent rearrangement of the PHYA gene. The mutation at FHY1 affects hypocotyl elongation but not germination, de-etiolation or flowering, suggesting that hypocotyl elongation is on a different branch of the transduction chain to these other responses and that FHY1 is a component of that branch. Hypocotyl elongation of fhy3 seedlings is affected in R, as well as in FR which may suggest that the transduction chain component encoded by FHY3 is shared by the phytochrome, or phytochromes, that control hypocotyl elongation in R. Characterisation of phyA and fhy mutants of Arabidopsis has led to elucidation of the roles of phytochrome A in different photomorphogenetic responses and some preliminary investigation of components of the transduction chain. This reseach has also further clarified the roles of other phytochromes and the extent of overlap of the spheres of action of distinct molecular species of phytochrome.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Guerrouani, Nadia. "Synthèse de copolymères amphiphiles triblocs PHA-b-PEG-b-PHA et greffés PVA-g-PHA : Modification de surface de films par plasma." Montpellier 2, 2005. http://www.theses.fr/2005MON20198.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Skřivanová, Veronika. "Metody identifikace PHA produkujících bakterií." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240529.

Повний текст джерела

Анотація:

This diploma thesis deals with testing, optimazing and comparing methods for the identification of bacteria producing polyhydroxyalkanoates. Work included cultivation and microscopy methods, wherein the bacterial cells were stained with lipophilic dyes Nile red and Sudan black. Further, we also used flow cytometry and spectroscopic methods - Raman spectroscopy and infrared spectroscopy with Fourier transformation, and molecular biological methods, which analyzed the presence of a gene encoding PHA synthase (phaC) by polymerase chain reaction (PCR). PCR assay consist of two reactions, the firt on eis based on amplification of phaC gene along with 16S rRNDA gene, which is common for all the bacteria (multiplex PCR). The second reaction is focused on specific amplification of PHA synthase catalyzing biosynthesis of mcl-PHA. In order to overcome false positive results typical for methods analyzing genotype and also to avoid false negative results occuring in fenotype analyzing methods, the best strategy is to combine both aproaches. According to our results, analysis of presence of phaC gene by PCR can be combined with methods capable of determining presence of PHA in bacterial cells. For this purpose, Raman microspectroscopy seems to be very promising tool, since it is able to detect low content of PHA in cells and PHA can not be confused with other lipid metabolites. The results provide an overview of test methods, their advantages and disadvantages and also to compare different criteria according to which it is possible to choose the method of identification in depending on the adjustable requirements.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Seeger, Martin. "Phra Dhammapiṭaka und die Pāli-Kanon-Debatte in Thailand ein Beitrag zur Untersuchung des modernen Buddhismus /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974091227.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Ravelli, Thandara Garcia. "Seleção de genes codificadores de PHA sintases para a construção de recombinantes em Burkholderia sacchari e Pseudomonas sp e avaliação da produção de polihidroxialcanoatos com diferentes composições monoméricas." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-11062015-103546/.

Повний текст джерела

Анотація:

Polihidroxialcanoatos (PHA) são poliésteres acumulados por diversas bactérias a partir de fontes renováveis e são termoplásticos, biodegradáveis e biocompatíveis. A variabilidade da composição monomérica de PHA determina suas propriedades mecânicas e permite seu uso em diversas aplicações. A PHA sintase é a enzima responsável pela polimerização do PHA. O objetivo deste trabalho foi à busca por genes codificadores desta enzima, construção e avaliação de recombinantes portando tais genes. Inicialmente buscaram-se novos genes de PHA sintase a partir de clones de uma biblioteca metagenômica previamente detectados por PCR como positivos para algum tipo de PHA sintase. Posteriormente buscou-se PHA sintases de classe III e construiram-se recombinantes de Pseudomonas sp e B. sacchari pela introdução de genes de C. vinosum (phaECCv). Nas duas recombinantes, os genes inseridos foram capazes de aumentar a fração de 3HHx em relação a linhagem selvagem, quando se utilizou glicose e hexanoato como fontes de carbono.
Polyhydroxyalkanoates (PHA) are polyesters accumulated from renewable sources by several bacteria and are thermoplastic, biodegradable and biocompatible. The variability of the PHA monomer composition determines its mechanical properties and allows their use in many applications. PHA synthase is the enzyme responsible for the polymerization of PHA. The objective was to search for genes encoding this enzyme, construction and the assessment of recombinant bacteria carrying such genes. Initially a screening of PHA synthase genes was made from a metagenomic library clones previously identified as positive by PCR for any type of PHA synthase. Later a search for class III PHA synthases was made as a construction of a recombinant Pseudomonas sp and B. sacchari by introducing genes of C. vinosum (phaECCv). In the two recombinant strains, the genes inserted were able to increase the fraction of 3HHx compared to the wild strain when glucose and hexanoate was used as carbon sources.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Klamsom, Prānī. "Kānkǣ panhā sētthakit thī kīeokap chāonā dōi withī kānsahakō̜n nai ratchasamai Phrabāt Somdet Phra Mongkutklao Čhaoyūhūa læ Phrabāt Somdet Phra Pokklao Čhaoyūhūa." Google Book Search Library Project, 1986. http://books.google.com/books?id=HUtXAAAAMAAJ.

Повний текст джерела

Анотація:

Thesis (M.A.)--Chulalongkorn University, 1986.
In Thai; abstract also in English. Added t.p.: Cooperative measures in solving economic problems related to peasants during the reigns of King Rama VI and King Rama VII. Includes bibliographical references (leaves 116-126). Also issued in print.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Brunetti, Lucia. "Electrospinning of PHAs composites filled with bioactive glass particles." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17525/.

Повний текст джерела

Анотація:

The use of composite materials, especially for the development of scaffolds, is having a great impact in the biomedical field. Every day thousands of surgical procedures are performed to replace or repair tissue that has been damaged through disease or trauma. The developing field of tissue engineering (TE) aims to regenerate damaged tissues by combining cells from the body with highly porous biomaterials scaffold, which act as templates for tissue regeneration, to guide the growth of new tissue. Consequently, there are a lot of researches focused on the development of new materials that must fulfill mandatory requirements such as biocompatibility, biodegradability, bioresorbability and adequate mechanical features. Scaffolds play a key role in the field of TE, thus they provide a healthy environment for cells attachment, differentiation, proliferation, and migration. Therefore, according to the native tissue, the mechanical and physiological characteristics of the biomaterials used for scaffolding are expected to be similar. In this work, electrospun fibers will be realized by investigating an innovative composition of the homopolymer Poly(3-hydroxybutyrate) (PHB) and the copolymer Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) for what regards the polymeric matrix, and the latter will be filled with bioactive glasses, in order to realize a composite material suitable for biomedical applications.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Viegas, Cristhiene Paiva Rohden. "Estudo da produção de polihidroxialcanoatos (PHAs) por Chromobacterium violaceum." Florianópolis, SC, 2005. http://repositorio.ufsc.br/handle/123456789/101917.

Повний текст джерела

Анотація:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Alimentos.
Made available in DSpace on 2013-07-15T23:32:30Z (GMT). No. of bitstreams: 1 222778.pdf: 2018552 bytes, checksum: 791791fc4e4bd5e0be25e93e2147d9f2 (MD5)
Estudou-se o efeito da adição de suplementos (acetato e ácido oléico) ou inibidor do metabolismo do propionato (itaconato), visando estabelecer condições nas quais a houvesse maior incorporação de unidades de 3HV, ao copolímero. A quantificação e caracterização dos polímeros foram feitas por cromatografia gasosa. Os resultados obtidos mostraram que sob limitação de fosfato, na presença de glicose e propionato 15 mM, ocorreu a maior incorporação de unidades de 3HV ao copolímero. Nestas condições, observou-se uma produção de 33,6% de P[3HB-co-3HV] na biomassa (0,086 g. L-1), contendo 18,3 mol% de 3HV. Em condições similares, porém sob limitação de nitrogênio, obteve-se uma produção de 31,6% de P[3HB-co-3HV] na biomassa (0,25 g. L-1), contendo apenas 3,6 mol% de 3HV. A suplementação da cultura, com extrato de levedura, sob limitação de fosfato, na presença de propionato 10 mM aumentou a produção de biomassa (0,16 g. L-1), porém, teve efeito negativo sob a incorporação de 3HV ao copolímero. C. violaceum é capaz de produzir P[3HB-co3HV], mesmo sem adição de um precursor de 3HV, provavelmente a partir de intermediários do metabolismo de aminoácidos. Tanto a suplementação com acetato, quanto com itaconato e ácido oléico, não incrementaram a incorporação de 3HV ao copolímero. Os pHs das culturas, ao final dos cultivos, atingiram valores iguais a 6,0 e 5,0, sob limitação de nitrogênio e fosfato, respectivamente, sugerindo que o decréscimo do efeito tamponante do fosfato, seja responsável pela inibição do crescimento celular, sob limitação do fosfato. Através deste estudo, foram definidas condições de cultivo para C. violaceum que permitiram a produção de copolímero com elevado percentual molar de 3HV, o que confere ao polímero características bastante interessantes do ponto de vista biotecnológico.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Botelho, Joana Caldeira. "Análise de culturas mistas produtoras de PHAs por microscopia." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/11771.

Повний текст джерела

Анотація:

Mestrado em Engenharia do Ambiente
Hoje em dia há uma necessidade crescente de encontrar uma solução viável, económica e sustentável para a substituição dos plásticos convencionais, que utilizam recursos não renováveis como matéria-prima para a sua produção. Além disso, quando depositados no ambiente tornam-se resíduos devido à sua alta resistência à biodegradação. O presente trabalho teve como objetivo principal o controlo biológico, através de análise microscópica, de doze reatores, sendo nove anaeróbios para acidificação, um MBBR e oito reatores descontínuos; sendo os restantes três reatores aeróbios, SBR. Efetuou-se a monitorização das variações morfológicas dentro dos reatores e correlacionaram-se com os parâmetros físico-químicos. A produção de AOVs nos reatores de acidificação para utilização como substrato dos microrganismos acumuladores de PHAs e a seleção de uma população dos microrganismos com elevada capacidade de acumulação desses polímeros nos reatores aeróbios foram também controladas através de análises microbiológicas. Ao longo do procedimento experimental dos reatores foram recolhidas amostras de lamas para a avaliação microbiológica qualitativa das mesmas ao microscópio e foram também determinados parâmetros físico-químicos e de operação dos reatores, assim como parâmetros biológicos. Os resultados obtidos permitem concluir que não é possível estabelecer correlações gerais entre parâmetros físico-químicos e biológicos, mas é possível estabelecê-las para casos de operação específicos, tal como a relação positiva entre a quantidade de flocos de pequenas dimensões e a intensidade de fluorescência emitida pelos grânulos de PHA nos reatores SBR1 e SBR2. Foi também possível obter um perfil de intensidades de fluorescência através da análise e tratamento de imagem em ImageJ. No entanto, não foi possível correlacionar o método de quantificação da fluorescência emitida pelos flocos corados com Azul do Nilo com as concentrações reais, pois não foi possível analisar quantitativamente o polímero acumulado no interior das células.
Nowadays there is a growing need to find a viable, economic and sustainable solution for the replacement of conventional plastics, which use non-renewable resources as a raw material for their production. Additionally, when improperly disposed in the environment, they are considered waste because of their high resistance to biodegradation. Furthermore, when thrown away, they become waste because of their highly resistance to biodegradation. The present study was aimed to biologically control, through microscopic analysis, twelve reactors, nine of them being anaerobic acidification reactors, one MBBR and eight batch reactors, and the remainders were aerobic reactors, SBRs. Monitoring was carried out for the morphological variations within the reactors and they were correlated with the physicochemical parameters. The VFA production in the acidification reactors to use as substrate for PHA accumulating microorganisms and the selection of a high PHA accumulating microorganism population in the aerobic reactors were also monitored through microscopic analysis. Throughout the experimental procedure, sludge samples were taken for qualitative microbiologic evaluation under the microscope and physicochemical, operating and biological parameters were also determined The results indicate that it is not possible to establish a general correlation between physicochemical and biological parameters, but correlation can be found for specific reactor conditions, such as the one found for SBR1 and SBR2, where the quantity of small aggregates appeared to have a positive correlation with the fluorescence intensity emitted by the PHA granules. It was also possible to obtain a fluorescence intensity profile by image analysis and processing in ImageJ. However, it was not possible to correlate the method of emitted fluorescence intensity by the Nile Blue stained flocs with real concentration values, since it was not possible to determine the quantity of stored polymer inside the cells.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Ferreira, Ana Lúcia Morgado. "Isolation and characterization of PHAs-accumulating bacteria from HSSL." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/13401.

Повний текст джерела

Анотація:

Mestrado em Biotecnologia - Biotecnologia Industrial e Ambiental
Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible biopolymers. PHAs emerge as a possible solution as substitutes of petroleum based plastics, being produced under the Biorefinery concept, in which wastes and by-products of numerous industries may be used as carbon source. This project aimed the isolation and characterization of organisms able to store PHAs from Hardwood Sulphite Spent Liquor (HSSL), a by-product of the pulp and paper industry. Isolation was performed from a Mixed Microbial Culture (MMC) selected under feast and famine conditions, using some components present in HSSL as substrates, such as acetic acid and xylose. Five pure isolates able to produce PHAs resulted from the successive streaking in solid medium containing HSSL. The purity of the isolates was evaluated through Gram staining and FISH analysis and the PHAs accumulation by Nile Blue staining. Two strains were identified as Rhohococcus spp. and three as Pseudomonas spp.. One isolate of each genus was selected and further studied in terms of growth and PHAs accumulation capability from three distinct carbon sources (HSSL, acetic acid and xylose). Both isolates, Rhodococcus spp. and Pseudomonas spp., were able to grow and use the three carbon sources as well as to produce PHAs. However, both strains showed a higher maximum specific growth rate (μmax) when HSSL was used as carbon source, 0.212 ± 0.0219 h-1 and 0.251 ± 0.0526 h-1, respectively. A qualitative evaluation of the PHAs accumulation through Nile Blue staining exhibited a higher accumulation when acetic acid was used as sole carbon source. In an attempt to identify some of the species responsible for PHAs accumulation of the selected MMC, belonging to the dominant class, Alphaproteobacteria, a 16S rDNA clone library was constructed. It was possible to identity Novosphingobium spp., Sphingobium spp. and Pleomorphomonas spp.
Polihidroxialcanoatos (PHAs) são biopolímeros biodegradáveis e biocompatíveis. Os PHAs são considerados uma solução possível como substitutos dos plásticos derivados do petróleo, podendo ser produzidos no âmbito do conceito de Biorefinaria utilizando resíduos como fonte de carbono. Este trabalho teve como objectivo o isolamento e a caracterização de bactérias produtoras de PHAs a partir de licor de cozimento ao sulfito ácido (HSSL), um sub-produto da indústria papeleira. Os isolamentos foram realizados partindo de uma cultura mista seleccionada para a acumulação de PHAs por imposição de ciclos de fome e fartura, utilizando alguns dos componentes do HSSL como substrato, nomeadamente a xilose e o ácido acético. Após repicagens sucessivas em meio sólido contendo HSSL, foi possível obter cinco isolados puros capazes de acumular PHAs. A pureza dos isolados foi avaliada através de coloração de Gram e análise FISH e a capacidade de acumulação de PHAs por coloração de Azul do Nilo. Duas estirpes foram identificadas como Rhohococcus spp. e três como Pseudomonas spp.. Um isolado de cada género foi seleccionado e estudado em termos de crescimento e capacidade de acumulação de PHAs, a partir de três fontes de carbono distintas (HSSL, ácido acético e xilose). Verificou-se que ambos os isolados, Rhodococcus spp. e Pseudomonas spp., foram capzes de crescer nos três meios e produziram PHAs. Contudo, ambas as estirpe apresentaram uma taxa específica de crescimento (μmax) superior com HSSL como fonte de carbono, 0.212 ± 0.0219h-1 e 0.251 ± 0.0526h-1 respectivamente. Uma avaliação qualitativa da acumulação de PHAs utilizando coloração Azul do Nilo mostrou uma acumulação maior nos ensaios em que o ácido acético era a única fonte de carbono. Numa tentativa de identificar algumas das espécies responsáveis pela acumulação de PHAs da cultura mista seleccionada pertencentes à classe dominante, Alfaproteobactéria, recorreu-se à construção de uma biblioteca de clones 16S rDNA. Foram identificadas as espécies Novosphingobium spp., Sphingobium spp e Pleomorphomonas spp.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Cruz, Daniel Henriques da Silva. "Acidificação de soro de queijo para produção de PHAs." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12420.

Повний текст джерела

Анотація:

Mestrado em Engenharia do Ambiente
A diminuição dos recursos fósseis bem como a abundância de biomassa renovável e que pode ser valorizada tem levado a encarar com boas perspectivas o processo de biorefinaria, sendo actualmente uma área em grande desenvolvimento. No sector dos plásticos os PHAs tem-se revelado uma alternativa sustentável em relação aos plásticos convencionais. O principal substrato para produzirem estes biopolímeros são os AOVs, produtos resultantes da fermentação acidogénica de resíduos orgânicos, como por exemplo o soro de queijo. Os AOV são compostos de alto valor económico devido às suas diversas aplicações. Neste trabalho foi estudado o processo de acidificação anaeróbio de soro de queijo, com a imposição na alimentação de valores de alcalinidade de 2000 e 5000 mg CaCO3/L e cargas orgânicas de 20 e 50 gCQO/L.d. Foram avaliadas as condições que produziam maior quantidade de ácidos e quais os tipos de ácidos mais produzidos em cada condição, num reactor MBBR. Foi também comparado a produção de AOV num reactor CSTR para a condição de 2000 mgCaCO3/L e 20 gCQO/L.d. Comparando as condições de 20 g CQO/Ld. e alcalinidade 2000 mg CaCO3/L e 5000 mg CaCO3/L é possível verificar que a produção de ácidos foi de 43301 mgCQO/L ± 618,3 e 5184,4 mgCQO/L ± 640,5, respectivamente, e o grau de acidificação foi de 41,6% ± 5,9 e 50,8%, respectivamente. Para a carga de 50 gCQO/L.d. e 2000 mgCaCO3/L verifica-se uma produção de ácidos de 10335,7 mgCQO/L ± 1077,6 e um grau de acidificação de 41,3%. Enquanto que para a mesma carga orgânica e alcalinidade 5000 mgCaCO3/L obteve-se 8693,6 mgCQO/L ± 1960,2 e um grau de acidificação de 30,1%. O ácido n-butírico é o mais produzido nas quatro condições. No reactor CSTR obteve-se uma média de 3555,69 mgCQO/L ± 706,89 e um grau de acidificação de 34,9%, valores estes menores do que os obtidos no MBBR nas mesmas condições. Todos os tipos ácidos são produzidos em maiores quantidades no MBBR, excepto o ácido i-valérico e n-caproico.
The decrease of fossil resources and the abundance of renewable biomass can be valued has led to face with good prospects biorefinery process , currently being an area in great development . In the plastics sector PHAs has proved to be a sustainable alternative to conventional plastics. The main substrate to produce these biopolymers are AOVs , products resulting from acidogenic fermentation of organic wastes such as cheese whey . AOVs have high economic value due to its various applications . In this work was studied,for various conditions of alkalinity , 2000 and 5000 mgCaCO3 / L and organic loading rate of 20 and 50 gCOD / L.d. that produced the largest amount of AOVs and wich kind of acids were produced in each condition , on a MBBR reactor . It was also compared the production of acids in a CSTR for the condition of 2000 mgCaCO3 /L and 20 gCOD / L.d. Comparing the conditions of 20 gCOD / L.day to 2000 mg CaCO3 / L and 5000 mg CaCO3 / L is possible to verify that the production of AOV were 43301 mgCQO/L ± 618,3 and 5184,4 mgCQO/L ± 640,5, respectively, and the degree of acidification was 41,6% ± 5,9 and 50,8% ± 3,9,respectively. For organic loading rate of 50 g COD / L.d. and 2000 mg CaCO3 / L there is a production of acids of 10335.7 mg COD / L ± 1077.6 and a degree of acidification of 41,32 %. While in the same organic loading and alkalinity of 5000 mg CaCO3 / L was obtained 8696,6 mg COD / L ± 1960,2 of AOVs and a degree of acidification of 30,1 %. N-butyric acid is the most produced AOV on all MBBR conditions. In the CSTR was obtained an average of 3555.69 COD mg / l ± 706.89 of AOVs and a degree of acidification of 34.92 %, which are lower than those obtained in the MBBR the same conditions. All kind of AOV are produced in a larger quantities on MBBR except i-valeric and n-caproic.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Rangel, Catarina Sofia Cirne. "PHAs from industrial waste by applying the threestep process." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15462.

Повний текст джерела

Анотація:

Mestrado em Biotecnologia
Currently one of the greatest concerns worldwide focuses on the development of new sustainable materials that can be used to replace petroleum-based products. For this reason, the study of the production of bioplastics has been subjected to considerable research in order to achieve process optimization and production costs reduction. In this context, the study of the production of polyhydroxyalkanoate (PHA) by mixed microbial cultures (MMC) is worthwhile. In this work, the three-step process was tested for PHA production. In a first step, a feedstock of the paper industry, hardwood sulphite spent liquor (HSSL) was submitted to acidogenic fermentation in order to produce a mixture rich in volatile fatty acids (VFAs), which was used as substrate in the next two steps. In the second step, a MMC collected from a wastewater treatment plant (WWTP) was submitted to Aerobic Dynamic Feeding (ADF) conditions in a Sequencing Batch Reactor (SBR) in order to select PHA-accumulating organisms. A pseudo-stationary state was reached after 60 days of SBR operation. In the third step, the ability of the selected MMC to accumulate PHA was tested. The selected MMC reached a maximum PHA content of 47.1%. The bacterial community was analysed through fluorescence in situ hybridization (FISH). Bacteria belonging to the four main classes were identified: Beta- (44.7 ± 2.7%), Alpha- (13.6 ± 1.3%) and Gammaproteobacteria (2.40 ± 1.1%) and Bacteroidetes (9.20 ± 3.8%). Regarding the genus level, inside the Betaproteobacteria, a considerable amount of Acidovorax (25.9 ± 3.1%) was found and only small amounts of Thauera (0.72 ± 0.25%) and Azoarcus (0.62 ± 0.02%) were detected. Defluvicoccus related to Tetrad Forming Organisms (0.75 ± 0.53%) belonging to Alphaproteobacteria was detected in small amount. A clone library was prepared and several clones were identified as organisms already described as PHA-producers.
Atualmente uma das grandes preocupações a nível mundial centra-se no desenvolvimento de novos materiais sustentáveis que possam ser usados em substituição dos produtos derivados do petróleo. Por este motivo, o estudo dos processos de produção de bioplásticos tem sido alvo de pesquisa intensiva de forma a conseguir alcançar a otimização e redução dos custos de produção destes materiais. Neste contexto, o estudo da produção de polihidroxialcanoatos (PHAs) por culturas microbianas mistas (MMC) faz todo o sentido. Neste trabalho, o processo de três passos foi testado para a produção de PHA. Numa primeira etapa, um subproduto da indústria papeleira, o licor de cozimento ao sulfito ácido (HSSL) foi submetido a fermentação acidogénica para produzir uma mistura rica em ácidos gordos voláteis (VFAs), que foi usada como substrato nas duas etapas seguintes. Na segunda etapa, a MMC recolhida numa estação de tratamento de águas residuais (WWTP) foi submetida a condições de alimentação dinâmica aeróbia (ADF) num reator descontínuo sequencial (SBR), de forma a selecionar os organismos acumuladores de PHA. Um estado pseudo-estacionário foi atingido após 60 dias de operação do SBR. Num terceiro passo, a capacidade da MMC selecionada em acumular PHA foi testada. A MMC atingiu um máximo de acumulação de PHA de 47,1%. A comunidade bacteriana foi analisada por fluorescence in situ hybridization (FISH). Foram identificadas bactérias pertencentes aos seguintes grupos: Beta- (44,7 ± 2,7%), Alfa- (13,6 ± 1,3%) e Gammaproteobacteria (2,40 ± 1,1%) e Bacteroidetes (9,20 ± 3,8%). A nível de género, dentro da classe Betaproteobacteria, uma quantidade considerável de Acidovorax (25,9 ± 3,1%) foi encontrada e foram detectadas em pequenas concentrações Thauera (0,72 ± 0,25%) e Azoarcus (0,62 ± 0,02%). Defluvicoccus relacionada com organismos formadores de tétradas (0,75 ± 0,53%), pertencendo à classe Alphaproteobacteria, foram detectadas em pequena quantidade. Uma biblioteca de clones foi preparada e vários clones foram identificados como organismos previamente descritos como produtores de PHA.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Drábková, Kateřina. "Biotechnologická produkce PHA pomocí Cupriavidus malaysiensis." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401869.

Повний текст джерела

Анотація:

The subject of this diploma thesis is the study of the production of polyhydroxyalkanoates (PHA) employing Cupriavidus malaysiensis. The aim of this thesis is to obtain and characterize the polymer with the most advantageous properties. The theoretical part deals with polyhydroxyalkanoates and their biotechnological production. Then selected microorganisms producing 3-hydroxybutyrate and 4 hydroxybutyrate, P(3HB co 4HB), are described. After that, the theoretical part deals with the production of PHA employing Cupriavidus malaysiensis. The bacterial strains of Cupriavidus malaysiensis DSM 19416, 19379 and 25816 were used in the experimental part. The strain Cupriavidus necator H16 was used as a control strain. First, the ability to utilize various carbon sources by the given bacterial strains was determined. Then, the aim was to select the optimal carbon source, a precursor for the synthesis of a polymer with high content of 4-hydroxybutyrate, and to determine the ideal culturing conditions for the growth of the microorganisms, which have been studied, and the production of P(3HB co-4HB). A two-stage culture and bioreactor culture was also performed to produce the desired copolymer. Furthermore, the production of terpolymer of 3-hydroxybutyrate, 4 hydroxybutyrate and 3-hydroxyvalerate, P(3HB co 4HB co 3HV), was studied by single stage and two-stage cultivation. In the last part, the produced polymers were characterized by gas chromatography with flame ionization detector (GC-FID), size exclusion chromatography with multi-angle static light scattering (SEC-MALS), differential scanning calorimetry (DSC) and thermogravimetry.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Kubáčková, Eliška. "Molekulárně biologická charakterizace vybraných producentů PHA." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-414162.

Повний текст джерела

Анотація:

This diploma thesis focuses on the molecular characterization of selected PHA producers. Within this work, the PHA producing thermophilic isolates originating from the samples of activated sludge and compost were identified and characterized using molecular biological methods. By sequencing the 16S rRNA gene, the thermophilic isolates were identified and taxonomically classified into the Firmicutes bacterial phylum. In these bacterial isolates, the ability to produce PHA at the genotype level was determined by conventional PCR detection of the phaC gene encoding PHA synthase, which is a key enzyme in PHA biosynthesis. Class I, II and IV PHA synthases were detected in most of the isolated bacteria, wherein class I and II PHA synthases are not characteristic for these bacterial genera. The largest proportion of isolates was identified for the species of thermophilic bacterium Aneurinibacillus thermoaerophilus, in which class IV PHA synthase was detected. In the second part of the diploma thesis, the RT-qPCR method was implemented to study the expression of selected genes of the bacterium Cupriavidus necator H16 involved in PHA metabolism. As part of the implementation of this method, PCR-based detection of selected genes was optimized and quantification of genes using real-time PCR was performed. The tested method included steps of RNA isolation, cDNA synthesis and quantification of gene segments for which the critical points of the method were determined based on the obtained data.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Pernicová, Iva. "Identifikace a izolace PHA produkujících bakterií." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-438296.

Повний текст джерела

Анотація:

Polyhydroxyalkanoates (PHA) are microbial storage polyesters that represent a renewable and environmentally friendly alternative to petrochemical plastics. However, their production and use are severely disadvantaged by the high production cost. The use of extremophilic PHA producers is one of the ways to reduce the cost of PHA production. Extremophiles bring numerous advantages resulting from the high robustness of the process against microbial contamination. In this doctoral thesis, attention was focused on the study of PHA production using selected halophilic and thermophilic microorganisms. Representatives of the genus Halomonas were mainly from public collections of microorganisms. Two promising PHA producers on waste frying oil were identified, namely Halomonas hydrothermalis and Halomonas neptunia. Both strains achieved good PHA yields in flask experiments. With the addition of suitable structural precursors, they were also able to produce copolymers with interesting material properties. However, in the proposed thesis, the main emphasis was placed on the study of PHA production using thermophilic microorganisms. As a part of the work, the isolation of thermophilic PHA producers from various thermophilic consortia (active sludge, compost, etc.) was performed. During isolations experiments, an original isolation procedure was designed using changes in osmotic pressure, the so-called osmoselection. Dozens of promising thermophilic PHA producers were obtained thanks to this original approach. They were taxonomically classified using 16S rRNA and tested for production potential. The most promising PHA producer was the isolate which was classified as Aneurinibacillus sp. H1. This bacterium is able to utilize a variety of substrates, including waste glycerol, to produce PHA. Even more important is the capability of synthesizing copolymers with a high content of 4-hydroxybutyrate. The monomer composition of the PHA copolymer and thus the material properties of the prepared copolymer can be controlled by suitable adjustment of the cultivation conditions. The prepared copolymer P(3HB-co-4HB) has unique properties and the great application potential in numerous high-end applications, for example in the field of health care, food industry or cosmetics.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Berglund, Alfred. "Ackumuleringspotential av PHA från restströmmar inom pappersbruk : En studie om PHA från Gruvöns, Bäckhammars och Skoghalls bruk." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67217.

Повний текст джерела

Анотація:

Plastic is one of the most universal materials used today. With a good future view, with new implementations and applications, it makes a lot of time to look at the production and management of the plastic materials. Plastic materials that have been used in our daily lives cause serious environmental problems. Millions of tons of these non-degradable plastics accumulate in the environment every year. The basic problem is that plastic is not naturally occurring in nature since containers are usually made of polyethylene terephthalate. This means that microorganisms do not have the ability to break it down to the current cycle. It takes hundreds of years for plastic containers to break down, not biologically but only degenerate into smaller and smaller pieces. Plastic breaks down into smaller pieces that become smaller and smaller until we cannot see them with the naked eye, mainly through heat and UV light. Although we cannot see them, they are still present and become part of our nature forever. Bioplastics is the plastic industry's tool to try to reduce these little pieces of our nature that will remain forever so that they do not grow more. With today's plastic packaging, which is said to be bioplastic, additives of, for example, cobalt and nickel, which are said to make it easier for the polymers to break down over time, have proven to be not as effective as they thought. Polyhydroxyalkanoates (PHA) are polymers which are biodegradable as based on their composition have different physical properties. PHA is a family of natural polyesters synthesized from various microorganisms discovered in 1926. Once discovered, interest has been high due to their biodegradability and its production from renewable resources. The polymers can be described generally as production from microorganisms under controlled conditions, where they occur naturally in organisms that classify them as biopolymers. Some of these polymers are already industrially produced on a large scale today. However, many still apply to several new areas but must be optimized for commercial production. Biopolymers can be classified into four groups. Amino-acid-based polysaccharides from bacteria, polyphenol-based and polyesters that this study is looking at. Depending on what the microorganisms possess for character traits and what they give to the substrate to break down, it gives polyesters with different physical properties. This case is a short-chain polyester to be formed, more specifically P3HB which is a three-carbon PHB polyester in its polymer which can be up to 5-7 units long. To avoid ongoing problems, a solution is needed. A solution that has received much attention to reduce plastic residues in nature is the use of biodegradable plastics and among them polyhydroxyalkanoates. Polyhydroxyalkanoates (PHAs) are common intracellular compounds found in bacteria, archaea and in few eukaryotes such as yeast and fungi. PHA acts as an energy storage polymer that is produced in some microorganisms when the carbon source is abundant and other nutrients such as nitrogen, phosphorus, oxygen or sulfur are limited. These polymers accumulate intracellularly up to 90% of the dry weight of the cell under nutritional conditions and act as energy saving materials. It has resembled mechanical properties like the traditional oil-based plastic such as polypropylene or polyethylene that can be formed with other synthetic polymers. PHA plastics possess many more applications, in agriculture, packaging and in the medical industry. It is biodegradable and also immunologically compatible. What the PHAs plaster can cause is an ultimate decomposition from a non-fossil source, which is exactly why it is very attractive. The purpose of this study was that from a hypothesis see within a limited time frame of ten hours of bio sludge from Gruvön, Skoghall and Bäckhammar's use could accumulate PHA with the aid of added readily degradable substrate. The process of the study will be a small part of a current research project together with Paper Province, Promiko, Pöyry and RISE. The aim of their study is to use residues from the forest industry to make hydrogen as well as bioplastics. This study will help to look at a subprocess of their cascading process. The aim of the study is to be able to measure the amount of PHA that could accumulate and rank the potential of the different uses. Using chemical analysis methods and extractions, it will provide opportunities to measure the accumulation of PHA in the various bacterial cultures of biomass from the use. The methods involve soxhlet extraction to successfully extract PHA from the bacteria. Dosage of substrate is sodium acetate piped from egg-diluted solution at 600 mg per dosage. In order for the dosage to be added at the right time, DO and the pH of the reactors were measured and logged throughout the course. FT-IR is used to view the course of events during the experimental period, linked to known features that may indicate that PHA is present in the bio sludge. Nutrients like phosphorus and nitrogen are measured, along with SÄ, SS, TOC, several before and after the experiment to compile discussion of the results. The conclusion was based on the analysis methods that the bio sludge that yielded the best yield was from Gruvöns use. This also relates best to the hypothesis of celebration and starvation, the relationship to which the bio sludge is exposed. The mine has a slurry in its five-step process which causes the bio sludge to return from step five where there is a shortage of food for bacteria to step three where there is a lot of food to consume. The rankings of the different uses relate to the hypothesis that the use of mining was best and the worst was the use of Bäckhammar. Based on the analysis methods included in the study, it can be concluded that the bio sludge that yielded the best yield was Gruvöns use with 13.6% of PHA / VS from the soxhlet extraction, the practice was best matched to the hypothesis. The ranking of the different bio sludge of the use is based on the hypothesis that Skoghall's use was second best followed by Bäckhammar's use which was the worst in accumulating PHA in the bacterial culture.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Pala, Martin. "Biodegradabilita přirozených a modifikovaných polyesterů bakteriálního původu a jejich kompozitů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216968.

Повний текст джерела

Анотація:

Presented work was focused on biodegradability of bacterial natural and modified polyesters and their composites. The first part of the work was focused on study of influence of PHA granules structure on their biodegradability using selected enzymes and influence of physiological conditions on PHA stability. Overall, tested polymer either in crytalinne or amorphous phase seems to be rezistent to attack of seleced hydrolytic enzymes such as lipases or proteases and is stable in simulated physiological fluids as well. Because of thies results, it is possible to use tested PHA materials in biomedical applications requiring rather resistant biomaterials. Second part of the work was focused on microbial degradation of modified PHA materials considering their potential environmental impact. Both mixed thermophillic culture originaly used in wastewater treatment plant and bacterial strain Delftia acidovorans were employed for biodegradation tests. Composites containing chlorine PHB and PHB films modified using plasticizers were tested. Films containing chlorine PHB cause inhibition of biomass growth to both tested cultures. The highest rate of degradation (31%) was observed in presence of bacterial culture with film containing 10% chlorine PHB. The results show that used microbial population is important factor affecting biodegradability.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Sundin, Anton. "Produktion av bioplast i Värmland? : Fermentering av olika avfallströmmar." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-36624.

Повний текст джерела

Анотація:

Ett av världens största miljöproblem är plastnedskräpning. På många platser kan spår av mänsklig närvaro ses i form av skräp av plast. År 2011 tillverkades det 280 miljoner ton plast, det motsvarar ungefär 28 000 Eiffeltorn. I Sverige förbrukades år 2010 ungefär 880 000 ton plast. I Asien produceras ungefär 50 % av all världens plast och Kina står för cirka hälften av detta. Nordamerika och Europa står för cirka 40 % av världens plastproduktion. Resterande produktion av plast är fördelat på Afrika och Sydamerika. Kommersiell plast är uppbyggd av små enheter kallade polymerer. Polymerer är i sin tur uppbyggda av ännu mindre enheter som kallas monomerer. Dessa monomerer är i dagsläget framställda av petroleum (råolja/mineralolja). Ungefär 4 % av världens oljekonsumtion går åt som råvara till att producera plast och lika mycket olja används som bränsle i tillverkningsprocessen. Begreppet bioplast är en hel familj av material som är biologiskt nedbrytbar, biobaserade eller bådadera. Det är dock inte en självklarhet att bioplaster besitter båda egenskaperna. PHA-plast är biobaserad och biologisk nedbrytbar, vilket är anledningen till att den står i fokus under detta examensarbete. För produktion av PHA-plast används en trestegsprocess, vilket innefattar ett fermenteringssteg, ett selektionssteg och ett ackumuleringssteg. Sist sker en extraktion för att frigöra PHA- plasten från det övriga organiska materialet. Syftet med det här examensarbetet är att med hjälp av framställning av bioplast främja miljön, vilket en anläggning som producerar bioplast skulle göra eftersom en del av den fossiloljebaserade plasten skulle kunna bytas ut mot bioplasten PHA. Större framställningsmöjligheter av bioplast i Värmland skulle medföra ett ökat intresse av en produktionsanläggning. Målet är att inventera olika industrier runt om i Värmland, i första hand matindustrier och skogsindustrier, och utreda deras processavloppsvattens potential att producera VFA. I detta examensarbete har fermenteringsförsök genomförts satsvis på processavloppsvatten från OLW, Barilla (Wasa), Skoghall, Gruvön och Rottneros. Försöken visar deras potential att producera VFA. Experimenten utfördes med ett konstant pH på 6 och varierande uppehållstid. Resultaten visade att OLW och Barilla har bäst potential till VFA-produktion med 4500 mg/l respektive 1610 mg/l. Spädning av OLWs och Barillas processavloppsvatten visade sig vara en gynnsam åtgärd, då VFA-produktionen ökade snabbare i jämförelse med de tester som utfördes vid icke-spädning. Dock erhölls inte lika stor totalmängd av VFA. Det är dock bättre att producera en större mängd VFA och på så vis låta processen ta längre tid. Vid fortsatta experiment rekommenderas att göra ytterligare försök på OLW och Barillas processavloppsvatten då de visade bäst potential till VFA-produktion.
One of the biggest environmental problems is the plastic littering. In many places traces of human presence is seen in the form of plastic littering. In the year 2011, 280 million tons of plastic was produced, which represents about 28 000 Eiffel Towers. In Sweden, about 880 000 tons of plastic a year is consumed, according to figures from 2010. Approximately 50 % of all the world's plastics are produced In Asia and China accounts for about half of it. North America and Europe account for about 40% of the world's plastic production. The remaining production is distributed between Africa and South America. Commercial plastic is made from small units called polymers. A polymer consists of smaller units called monomers. In present, these monomers are produced out of petroleum (crude oil/ mineral oil). Approximately 4% of the world’s oil consumption is spent as raw material to produce plastic and the same amount of oil is used as fuel in the plastic production process. The term bio-plastic is used for a family of materials which are biodegradable, bio- based or both. However, it is not given that bioplastics do possess both properties. PHA plastics are both bio based and biodegradable, which is why it is the focus for this thesis. Production of PHA plastic is a three-step process comprising a fermentation step, a selection step, and an accumulation stage. Finally, there is an extraction to release the PHA plastic from the organic material. The aim of this thesis is to aid the production of bioplastics in order to lessen the environmental load of plastics. The more bioplastic that can be produced, the greater the interest of a bioplastic-producing plant in Värmland. The goal is to make an inventory of industries around Värmland, primarily food industries and forest industries, and to quantify the potential of their process wastewaters to produce VFA. In this thesis, fermentation experiments conducted batch-wise was performed with process wastewater from OLW, Barilla (Wasa), Skoghall, Gruvön and Rottneros. The experiments showed the wastewaters potential to produce VFA. The experiments were performed with a constant pH of 6 and with varying residence time. The results showed that OLW and Barilla has the highest potential for VFA production with 4500 mg/l and 1610 mg/l, respectively. Dilution of OLWs and Barillas process water turned out to be favorable, as the VFA production increased rapidly in comparison with those tests that were conducted under non-dilution. The total production of VFA, however, was not as high. In further experiments, it is recommended to make another attempt at the OLWs and Barillas process wastewater since they showed the best potential for VFA production.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Phua, Dazril I. Verfasser], Andrij Z. [Akademischer Betreuer] [Pich, and Alexander [Akademischer Betreuer] Böker. "Photo-responsive microgels / Dazril I. Phua ; Andrij Pich, Alexander Böker." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130871789/34.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Kaimook, Nattaporn. "The study of Wai Phra Kao Wat in Bangkok, Thailand." Thesis, Durham University, 2018. http://etheses.dur.ac.uk/12874/.

Повний текст джерела

Анотація:

The study presents a new form of pilgrimage introduced by Thai authorities and involving visiting to nine temples (Wai Phra Kao Wat) in Bangkok. I will focus on four main aspects of this phenomenon. Firstly, the study will describe the dynamic application of the practice (Wai Phra Kao Wat) including the forms of devotion, the designation of temples by authorities, the pilgrims’ experience, and the role played by local ‘communities’ (chumchon). Secondly, the study will consider this pilgrimage as a case study with which to explore how Thai cultural phenomena provide multiple avenues for Thai people to reflect on their perception of the relation between Buddhism (Theravada Buddhism in particular) and the state. Thirdly, the study explores the contribution of ‘new’ performances of religiosity in popular Buddhism into shaping modern economy and rhetorical politics. Lastly, the study will provide the significance of Wai Phra Kao Wat that could shed light on important contemporary Thai cultural phenomena such as the emergence of ‘pilgrimage tourism’ on socio-cultural and economic changes and the relationship between ritual practice and Thai citizenship. The ethnographic methods including participant observation and interviewing are mainly employed throughout the fieldwork. I conclude that Buddhism in contemporary Thailand becomes an instrument to negotiate identities and meanings at the level of governance. Wai Phra Kao Wat, a state-oriented campaign, has been then utilised to enhance Thai capital’s venture into the global economy as well as to establish regime legitimacy with the inculcation of nation, religion, and monarchy.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Šuráňová, Zuzana. "Využití PHA produkujících kmenů v bioremediačních technologiích." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316181.

Повний текст джерела

Анотація:

The aim of this work is study of utilization of PHA producing bacteria in bioremediation technologies. For this study were used bacteria Pseudomonas putida KT2440 and two isolates from soil contaminated by petroleum - Pseudomonas gessardii (D2) a Pseudomonas fulva (D3). The experimental part describes especially study of feather biodegradation using selected microbial strains. All the tested bacterial strains were capable of feather degradation and utilization as the sole carbon source. During biodegradation experiment, we monitored weight loss of feather, protease and keratinase activity, concentration of bacterial biomass and PHA content as well as pH. The highest biodegradation ability and keratinase activity was observed in Pseudomonas putida. None of tested bacteria accumulated detectable amount of PHA during growth on waste feather, nevertheless, bacterial biomass grown during feather degradation can be used as an inoculum for PHA production on waste frying oil and octanoic acid. Using this experimental setup, high PHA content (54% of cell dry weight) was achiaved in Pseudomonas putida. Another part of the thesis deals with biodegradation of petroleum oil. The highest capability of growth on this carbon source were determined in Pseudomonas fulva.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Brondová, Zuzana. "Bioinformatická analýza PHA syntáz u termofilních bakterií." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449376.

Повний текст джерела

Анотація:

The thesis deals with bioinformatics analysis, the aim of which was to find a suitable producer of PHA for new generation industrial biotechnologies from the collection of found thermophilic bacteria. Part of experiments was the finding of several thermophilic bacteria based on the similarity of the protein sequence of the phaC gene of the bacterium Cupriavidus necator. The next part of thesis was a literature search of the abilities of these thermophilic bacteria focused on culture conditions and the spectrum of usable substrates. Subsequently, five bacteria were selected for use in NGBI based on the information obtained. Freely available databases were used during the experimental work, and evolutionary analysis were performed in MEGA X and Operon-mapper. Rubrobacter xylanophilus with collection number DSM 9941 was selected from the collection of bacterial strains as the most promising PHA producer for NGIB. The high culture temperature of up to 70 ° C and a large amount of utilized carbohydrate substrates were considered decisive. An interesting result of the analysis was to find the gene sequences of two classes of PHA synthase – I. and III. class, as for a single bacterial strain from the entire collection. Additional genes linked to PHA metabolism were found in genome analysis.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Vašířová, Kristýna. "Evoluční inženýrství cyanobakterií v kontextu akumulace PHA." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449377.

Повний текст джерела

Анотація:

The aim of this diploma thesis was to subject selected cyanobacterial strains to adaptive evolution and subsequently investigate the properties of the resulting adapted strains, especially their changes related to polyhydroxyalkanoates (PHA) accumulation. The theoretical part of the work describes in more detail the issue of cyanobacteria, PHA and their interconnection in the field of evolutionary engineering. Cyanobacterial strains Synechocystis sp 6803 and. Synechocystis salina CCALA 192 were used for evolutionary experiments. Selection pressures of hydrogen peroxide and copper. were applied to selected representatives. The resulting cultures and their ability to accumulate PHA were subsequently assessed by gas chromatography. Both of these selection pressures proved to be unsuitable, as strong growth inhibition was observed after their application to cultures, which did not allow the application of evolutionary engineering methods. In the second half of the experimental part, the provided adapted strains to 6% NaCl were monitored. Adaptation has been shown to have a positive effect on microorganisms, as they have a higher biomass content, better stress resistance and a slight increase in PHA accumulation.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Kovářová, Radka. "Biotechnologické produkce PHA kopolymerů obsahujících 4-hydroxybuytrát." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449403.

Повний текст джерела

Анотація:

The proposed diploma thesis aims to study the biotechnological production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer. The subject of the experimental part was first to select a suitable bacterial strain from five selected microorganisms with different carbon precursors applied at various concentrations. The five selected microorganisms used in the experimental part include bacterial strains Cupriavidus malaysiensis DSM 19416, DSM 19379, and DSM 25816. Furthermore, the strain Thermomonas hydrothermalis DSM 14834 and Aneurinibacillus thermoaerophilus H1 CCM 8960. The experiment shows that the most suitable candidate for biotechnological production is the bacterial microorganism Cupriavidus malaysiensis DSM 19379. Finally, the biotechnological production of the copolymer was investigated utilizing a batch cultivation technique in a laboratory bioreactor.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Dlouhá, Karolína. "Nové způsoby isolace PHA z bakteriální biomasy." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449417.

Повний текст джерела

Анотація:

The aim of this diploma thesis was study of the isolation of polyhydroxyalkanoates using a commercial surfactant and selected biosurfactants, which were sophorolipids, coconut soap, lecithin, lauryl glucoside, coco glucoside and cocamidopropyl betaine. PHA was isolated from Schlegelella thermodepolymerans DSM 15344, where the amount of NaCl in the production medium was first optimized. The molecular weight of the isolated polymer was analyzed by SEC-MALS. The largest structural changes were recorded for coconut soap. Possible impurities in the isolated polymer were analyzed by infrared spectrometry (ATR-FTIR). The least protein contamination of the polymer was recorded with coconut soap. From the above biosurfactants, coconut soap, lauryl glucoside and coco glucoside were selected, because the highest purity of PHA was obtained. However, coconut soap had the greatest potential. The isolation temperature and surfactant concentration were optimized for selected biosurfactants. The best results were obtained at 90 °C and a concentration of 5 g/L. Furthermore, the versatility of the isolation method was tested using selected biosurfactants on various thermophilic microorganisms, which were Chelatococcus composti DSM 101465, Schlegelella thermodepolymerans DSM 15264, Tepidimonas taiwanensis LMG 22826 and Aneurinibacillus thermoaerophilus H1.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Arab, Goueini Shahdokht. "Produktion av polyhydroxialkanoater (PHA) med Bacillus megaterium." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-26353.

Повний текст джерела

Анотація:

Plastproduktionen och användningen av plast ökar varje år i hela världen och detta är ett av världens största problem. Plaster är ett svårnedbrytbart ämne och processen kan ta hundratals år. Detta leder i sin tur till att plastackumuleringen orsakar skadlig påverkan på klimat, miljö och människor. Ett av alternativen som har stor potential för hanteringen av detta problem är att minska användningen av plast och i stället öka produktionen och användningen av bioplastereller biopolymerer som är nedbrytbar. Bioplaster har kortare nedbrytningstid än vanliga plaster och därför är bioplast ett bra alternativ istället för att använda vanliga plaster. Det finns tre olika grupper av bioplaster, nämligen dem som är biobaserade, bionedbrytbara och de som är både biobaserade och bionedbrytbara. Entyp av bioplast som är biologiskt nedbrytbar och biobaserad är polyhydroxialkanoater (PHA)som används i olika branscher då PHA är en av de biopolymerer som visar störst potential attersätta plast i framtiden. Forskning pågår på Högskolan i Borås med målet av att bilda en ny process för produktion och återvinning av PHA. Processen baseras på produktion av PHA från flyktiga fettsyror som produceras från acidogen jäsning. Acidogen jäsning är en modifierad process av anaerobmatsmältning som används idag för produktion av biogas från avfall. Den kan vara den rättaprocessen för återvinningen av PHA-baserade avfall och för att producera ett billigt substrat, nämligen flyktiga fettsyror för PHA produktion. Det här projektet handlar om en del av processen, nämligen produktion av PHA med bakterier. Forskningsgruppen på Högskolan iBorås har en bakteriestam som inte har undersökts för produktion av PHA. Innan bakterien kan studeras för produktion av PHA från flyktiga syror behövs medelinnehållet optimeras för bakterietillväxt. Syftet med detta arbete är att undersöka effekten av olika glukoskoncentrationer som kollkälla och olika mängder av ammoniumsulfat som används vid tillväxt av den bakterien Bacillusmegaterium för produktion av PHA. En jämförelse mellan det definierade mediet som användsi detta arbete och dess ersättning med nutrient broth, ett komplext medium som normalt används för bakterietillväxt genomfördes också för att utvärdera lämpligheten hos mediet underutveckling för att framgångsrikt stödja bakterietillväxt. Under detta arbete användes flera olika analytiska tekniker såsom pH mättning, Högupplösande vätskekromatografi (HPLC),Spektrometer (OD mättning), och Fourier-transform infraröd spektroskopi (FTIR) för att utvärdera bakterietillväxt och produktion av PHA samt analysera sammansättningen av PHAs. Mängden av ammoniumsulfat påverkade glukosförbrukningen, där koncentrationer av 3 g/Loch 7 g/L visades att leda till en snabbare glukosförbrukning jämfört med 5 g/L. Därför valdes3 g/L ammoniumsulfat då det innehåller mindre kemikalier användning och påverkar inte celltillväxten på ett negativ sätt. Under experimentet med användning av 3 g/Lammoniumsulfat med 10 g/L glukos, konsumerades glukosen fullständigt vid 72 timmar av bakterietillväxt och den maximala PHA-produktionen var på 13–14% baserad på torr cell vikt. Tillväxtmedelet som utvecklades i det här projektet visade att vara lämplig för bakterietillväxt eftersom användning av nutrient broth som används normalt för bakterietillväxt ledde till långsammare glukosförbrukning. Initial glukoskoncentration (5, 10 och 20 g/L) påverkade inte glukosförbrukningen och får studerats vidare för att öka cellkoncentrationen och följaktligen produktionen av PHA. En av det mest studerade i PHA-familjen är polyhydroxibutyrat (PHB). Under detta arbete visade det sig att genom användning av FTIR att PHB framställdes.
Plastic production and use of plastic are increasing every year throughout the world and this is one of the world's biggest problems. Plastic is a persistent substance, and its biodegradation process can take hundreds of years. This in turn leads to the accumulation of plastic causing harmful effects on the climate, the environment, and people. One of the alternatives that has great potential when it comes to dealing with this problem is to reduce the use of plastics and instead increase the production and use of bioplastics or biopolymers that are biodegradable. Bioplastics have a shorter biodegradation time than plastics and therefore bioplastics are a good alternative instead of using ordinary plastic. There are three different groups of bioplastics, namely those that are bio-based, those that are biodegradable and those that are both bio-based and biodegradable. One type of bioplastic that is biodegradable and bio-based is Polyhydroxyalkanoates (PHA) which are used in various industries as PHA is one of the biopolymers that shows the greatest potential to replace plastic in the future. Research is underway at the University of Borås with the goal of developing a new process for the production and recycling of PHAs. The process is based on the production of PHAs from volatile fatty acids produced from acidogenic fermentation. Acid fermentation is a modified process of anaerobic digestion; the latter is used nowadays to produce biogas from waste and can be the right process for recycling PHA-based waste and for producing a cheap substrate, namely volatile fatty acids for PHA's production. This project is about a part of the process, namely the production of PHAs with bacteria. The research group at the University of Borås has a bacterial strain that has not been yet investigated for the production of PHAs. Before this bacterium can be studied for the production of PHAs from volatile fatty acids the compositionoptimization of the cultivation medium for bacterial growth is needed. The purpose of this work is to investigate the effect of different glucose concentrations as a source of carbon and different amounts of ammonium sulphate in the growth of the bacterium Bacillus megaterium and the production of polyhydroxyalkanoates. A comparison between the defined medium under development in this project with nutrient broth, a complex medium normally used to grow bacteria, was also carried out in order to evaluate the suitability of the defined medium to support bacterial growth. During this work several different analytical techniques have been used such as pH measurement, High-Performance Liquid Chromatography (HPLC), Spectrometer (for optical density (OD) measurement), and Fourier-Transform Infrared Spectroscopy (FTIR) to evaluate bacterial growth and production of PHA as well as PHAs composition. The amount of ammonium sulphate affected glucose consumption rate, where concentrations of 3 g/L and 7 g/L were shown to lead to a faster glucose consumption compared to that at 5 g/L. Therefore, 3 g/L ammonium sulphate was chosen as it represents less chemical consumption while not affecting cell growth negatively. During bacterial cultivation in a medium containing 3 g/L ammonium sulphate, 10 g/L glucose, among other compounds, glucose was completely consumed after 72 hours of bacterial growth and the maximum PHA production was 13-14% based on cell dry weight. The cultivation medium developed in this project was shown to be suitable for bacterial growth since the use of nutrient broth, normally used for bacterial growth, led to slower glucose consumption. Initial glucose concentration (5, 10 and 20 g/L) did not affect glucose consumption rate and should be further studied to increase cell concentration and consequently the production of PHA. One of the most studied polymers in the PHA family is polyhydroxybutyrate (PHB). During this work, it was found, through the use of FTIR, that PHB was produced.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Sharma, Umesh. "Development of sustainable microbial fermentation strategies for the production of medium-chain length polyhydroxyalkanoates (mcl-PHAs) from biodiesel derived glycerol." Not applicable, 2015. http://hdl.handle.net/1993/30658.

Повний текст джерела

Анотація:

Bio-plastics have emerged as a promising alternative to conventional petrochemical derived plastics particularly over the past few decades. Numerous production methods for bio-plastics have been researched; however, work remains towards developing a commercially viable and economical process. The purpose of this research was to develop a sustainable fermentation strategy for production and scale-up of medium-chain length polyhydroxyalkanoates (mcl-PHAs), or bio-plastics, using a novel strain of the gram negative bacterium Pseudomonas putida, LS46, with biodiesel derived waste glycerol (WG) as feedstock. Experiments were conducted to gain a basic understanding of the general growth patterns exhibited by LS46. Thereafter, flask-batch experiments were conducted to study effects of variation in media conditions upon cell biomass production and mcl-PHA accumulation. Subsequently, optimal medium conditions observed within flasks were scaled-up and employed in the operation of a pilot-scale fermenter to increase production capacity for mcl-PHAs. It was concluded that mcl-PHA production at commercial levels could be viable with advanced process optimization.
October 2015

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Vlasáková, Terézia. "Isolace, identifikace a charakterizace extremofilů schopných produkce PHA." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376875.

Повний текст джерела

Анотація:

This diploma thesis is focused on isolation and identification of thermophilic microorganisms capable of production of polyhydroxyalkanoates (PHA) in the sample of activated sludge from wastewater treatment. 6 culture samples were isolated from activated sludge by means of cultivation technics and methods of molecular biology. They were closer specified by comparing nucleotide sequences of 16S-rRNA gene and assigned to bacterial genus Anoxybacillus. The production of PHA by this genus was not reported in literature so far. Samples were confirmed to contain phaC gene that codes the enzyme PHA-synthase and they also gave a positive response to staining colonies with Nile red, what refers to presence of intracellular lipidic structures. However, the PHA production by isolates was not successful. The reason should be an inappropriate production medium or conditions. The positive phenotype result of Nile red dyeing was probably achieved by production of huge amount of lipids by bacterial cells that provides similar fluorescence than PHA granules.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Schmidt, Bastian. "Veränderungen im LPS-Muster von E.coli Shigella durch cld pHS_-1tn2." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980061172.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Lee, David. "Increasing arsenic tolerance in plants : unexpected roles for phosphate and PHYA /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3071018.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Fiuza, Tiago da Luz. "Efetividade do (PhSe)2 em proteger contra a toxicidade do HgCl2." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/11228.

Повний текст джерела

Анотація:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Mercury (Hg) is a non-essential metal without biological function and also an environmental pollutant originating from various sources, especially from areas of mineral exploration and intense industrial activity. It is well known that Hg has a high affinity for thiol groups (SH) causing several biochemical changes that induce oxidative stress. On the other hand, selenium (Se) is an essential trace element involved in many processes in metabolism, especially which are related to antioxidant defense system. The diphenyl diselenide (PhSe)2 is an organic selenium compound with pharmacological properties, such as antioxidant and anti-inflammatory. The objective of this study was to evaluate the protective effect of (PhSe)2 against intoxication induced by mercuric chloride (HgCl2) poisoning. For this Swiss albino mice (17-25g) were treated for five consecutive days with (PhSe)2 5.0 mg/kg or canola oil by oral gavage and with HgCl2 5.0 mg/kg or saline by subcutaneous injection for more five days. The animals were sacrificed 24 hours after the last administration of HgCl2 and samples of blood, kidney and liver tissue were collected for δ-aminolevulinate dehydratase (δ-ALA-D) activity assays. The activity of serum AST and ALT and serum urea and creatinine levels were assessed as parameters of hepatic and renal toxicity, respectively. Oxidative parameters, total thiols, non-protein thiols and the levels of thiobarbituric acid species were also evaluated. Levels of Hg and Se were determined in tissues. The animals exposed to mercury showed an inhibition of blood δ-ALA D activity, which was partially prevented by (PhSe)2. Regarding the parameters of liver and kidney toxicity, animals exposed to Hg showed an inhibition of ALT activity and an increase in creatinine levels, been this last completely prevented by (PhSe)2. On oxidative parameters evaluated, a decrease in thiobarbituric acid reactive specimens (TBARS) levels and an increase in non-protein thiols in the renal tissue were observed. This increase was partially prevented by (PhSe)2. Animals exposed to Hg showed high levels of this metal in the kidney, liver and blood. Animals exposed to Hg and pre-treated with (PhSe)2 showed a decrease of Hg levels in the blood and an increased in the liver when compared to those only treated with Hg. Therefore, considering the results presented and the antioxidant properties of (PhSe)2 and the mechanisms underlying the toxicity of mercury, it is believed that (PhSe)2 may be a potential agent against mercury poisoning.
O mercúrio (Hg) é um metal não essencial, ou seja, sem função biológica e também um poluente ambiental originário de diversas fontes, principalmente de áreas de exploração de minérios e atividade industrial intensa. É bem conhecido que o Hg possui uma alta afinidade por grupamentos tiois (SH) ocasionando diversas alterações bioquímicas que podem induzir ao estresse oxidativo. O selênio (Se) por sua vez, é um elemento traço essencial, pois está envolvido em diversos processos metabolicos, principalmente naqueles envolvidos no sistema de defesa antioxidante. O disseleneto de difenila (PhSe)2 é um composto orgânico de selênio com propriedades farmacológicas, das quais destacam-se suas propriedades antioxidantes e antiinflamatórias. O objetivo deste trabalho foi avaliar o efeito protetor do (PhSe)2 contra a intoxicação induzida por cloreto de mercúrio (HgCl2). Para isso foram utilizados camundongos Swiss albinos (17-25 g) os quais foram tratados por cinco dias consecutivos com (PhSe)2 5,0 mg/kg ou óleo de canola por via oral, e nos cinco dias seguintes com HgCl2 5,0 mg/kg ou salina, por injeção subcutânea. Os animais foram sacrificados 24h após a última administração de HgCl2 e as amostras de tecido sanguíneo, renal e hepático foram coletadas para a analise da atividade da enzima δ-aminolevulinato desidratase (δ-ALA-D). A atividade da ALT e AST séricas e os níveis séricos de uréia e creatinina foram avaliados como parâmetros de toxicidade hepática e renal, respectivamente. Também foram avaliados os parâmetros oxidativos, tiois totais, tiois não protéicos e os níveis de espécies reativas ao ácido tiobarbitúrico. Foram determinados também os níveis de Hg e Se nos tecidos. Os animais expostos ao mercúrio apresentaram uma inibição da atividade da enzima δ-ALA-D sanguínea, a qual foi parcialmente prevenida pelo (PhSe)2. Quanto aos parâmetros de toxicidade hepática e renal, os animais expostos ao Hg apresentaram uma inibição na atividade da enzima ALT e um aumento nos níveis de creatinina, o qual foi prevenido totalmente pelo (PhSe)2. Em relação aos parâmetros oxidativos, foi observado uma diminuição nos níveis de espécies reativas ao acido tiobarbiturico (TBARS) e um aumento nos níveis de tiois não protéicos no tecido renal. Este aumento foi parcialmente prevenido pelo (PhSe)2. Os animais expostos ao Hg apresentaram níveis elevados deste metal no rim, fígado e sangue. Os animais expostos ao Hg pré-tratados com (PhSe)2, apresentaram níveis diminuídos de Hg no sangue e aumentados no fígado em relação aos animais tratados somente com Hg. Considerando os resultados apresentados e tendo em vista as propriedades antioxidantes do (PhSe)2 e os mecanismos envolvidos na toxicidade do mercúrio, acredita-se que o (PhSe)2 pode vir a ser um agente em potencial contra a intoxicação por mercúrio.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Motib, Anfal Shakir. "Functional characterisation of TprA/PhrA quorum sensing system in Streptococcus pneumoniae." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/42021.

Повний текст джерела

Анотація:

Quorum-sensing (QS) mechanisms are pivotal for microbial adaptation to host environments, and often required for pathogenesis without affecting bacterial vitality. Hence targeting QS diminish the fitness cost of inhibition, and the emergence and spread of antibiotic resistance. I characterized the TprA/PhrA QS system in the important human pathogen Streptococcus pneumoniae with a view to target its operation using novel soluble linear molecularly imprinted polymers (LMIP). I found that TprA/PhrA system is commonly found in pneumococcal strains, and is required for mucin, galactose and mannose utilisation. On galactose, TprA is an activator of the virulence determinant neuraminidase (nanA), and controls the expression of nine different operons on galactose and mannose. tprA and phrA mutants are highly attenuated in the mouse model of pneumonia and septicemia, and in the chinchilla model of otitis media, indicating that the TprA/PhrA system is a major virulence determinant and a highly relevant anti-infective target. To interfere with the operation of TprA/PhrA, I used, for the first time, highly homogenous soluble LMIP specific to the PhrA peptide. LMIP decreased PhrA-induction in a dose-dependent and sequence-specific manner, and possessed no visible toxicity in the murine model. It was also shown that LMIP were protective against lethal pneumococcal challenge. This study sets the stage for studies on a novel class of drugs to target Gram positive pathogens.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Testard, Emilie. "บทละครเรื่องพระมะเหลเถไถ ของ คุณ สุวรรณBotlakhǭn rư̄ang phra malēthēthai khong khun suwan". Paris, INALCO, 2004. http://www.theses.fr/2004INAL0027.

Повний текст джерела

Анотація:

Traduction et pérégrinations poétiques à travers le Bot lakhon rueng phra malethethaï de Khun Suwan. Le long poème de Khun Suwan intitulé Bot Lakhon Rueng Phra Maléthéthaï ne fut pas mis à l'écrit du vivant de la poète. Khun Suwan a en effet placé son oeuvre dans l'oralité tant dans sa réalisation que dans sa transmission. Le poème se présente comme une oeuvre vouée à la représentation théâtrale. Classique dans sa forme et dans son style, cette oeuvre respecte les règles poétiques et les conventions théâtrales du genre Lakhon. Après avoir étudier l'évolution de ce genre intimement attaché au pouvoir monarchique et placé la poète dans son environnement littéraire, nous verrons comment ses deux oeuvres majeures, à savoir le Bot Lakhon Rueng Phra Maléthéthaï et le Bot Lakhon Unarut Roï Rueng annoncent la décadence de ce genre désuet. S'attachant à ridiculiser les épopées héroïques, Khun Suwan compose son poème comme une parodie des pièces traditionnelles et en particulier de la grande oeuvre du roi Rama II, Bot Lakhon Inao. Elle détourne les intrigues habituelles et fait du prince Maléthéthaï l'un des premiers anti-héros de la littérature siamoise. Parodie de Lakhon, le poème de Khun Suwan est aussi une satire du style des poètes néo-classiques. En détruisant un à un les clichés littéraires, Khun Suwan annonce avec le Bot Lakhon Rueng Phra Maléthéthaï la fin d'une ère. En effet, le poème, après être apparu comme un désordre inextricable de phonèmes se suivant au hasard, se révèle être, suite à un examen plus poussé de sa construction, une oeuvre composée avec une extrême rigueur. Devenu aussi concret que la matière, le langage est détruit, disséqué, défait, disloqué et reconstruit selon la volonté du poète. Tout le poème est en réalité un exercice formel jouant sur la permutation des particules sonores. Fondatrice d'une certaine modernité, Khun Suwan introduit une nouvelle conception poétique à la fois ludique et combinatoire
Translation and poetic journey through the Bot Lakhon Rueng Phra Malethethai by Khun Suwan. Khun Suwan's poem entitled Bot Lakhon Rueng Phra Maléthéthaï as we can read it today has never been written by its author. It seems as though the poet decided that it should exist and be transmitted though oral means. The Lakhon genre to which Khun Suwan's poem complies is vowed to be played on stage. After a description of the poet's literary environment, of the Lakhon and it's evolution, we will explain how Khun Suwan's Bot Lakhon Rueng Phra Maléthéthaï and Bot Lakhon Unarut Roï Rueng announce the decrepitude of an old fashion dramatic genre. The Bot Lakhon Rueng Phra Maléthéthaï is a parody of the traditional Lakhon plays. Khun Suwan makes fun of the old fashion heroic epics and more especially of King Rama II's masterpiece Bot Lakhon Inao. The poet puts the conventional intrigues up side down and price Malethethaï is the first anti-hero of Siamese literature. Not only is Khun Suwan unconventional play is parody of the Lakhon genre, it is also a satire of the neo-classic style. By the destruction of the artistic cliché, Khun Suwan announces the end of an era. Her poem seems to be a chaotic and illogic melting pot of sounds with no significance, but after having examined its structure it appears that Khun Suwan's poem has been composed in order to comply with very strict laws. The words are dismantled, and only the sounds remain. Language is reduced to its very essence, which is pure sound. Khun Suwan invents a new way of communication and makes of her poem a game of sound permutation. With her poetic conceptions, she opens the way to a certain modernity. Poetry from now on has to be considered as an entertaining and combining art

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Pinto, Ana Luísa Ferreira. "Produção de PHAs para valorização de um resíduo da indústria vinícola." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12596.

Повний текст джерела

Анотація:

Mestrado em Biotecnologia - Biotecnologia Industrial e Ambiental
O objetivo deste trabalho consistiu na valorização do folhelho de uvas brancas, um subproduto da indústria vitivinícola rico em monossacarídeos, através da produção de polihidroxialcanoatos (PHAs) pelos microrganismos Cupriavidus necator e Haloferax mediterranei. Os PHAs são poliésteres intracelulares acumulados por microrganismos como reservas de carbono, com valor comercial pela sua natureza biodegradável e biocompatível. De modo a avaliar a produção de PHAs pelos dois microrganismos, realizaram-se ensaios em meio definido suplementado com glucose e manose (meio sintético MG), os açúcares predominantes no extrato, em extrato aquoso de folhelho (EAF) suplementado com os constituintes do meio mineral. Dos ensaios realizados em erlenmeyer com C. necator em EAF verificou-se que a bactéria era capaz de crescer a uma taxa específica máxima de 0,19 h-1 até uma concentração de biomassa final de 17,11 g/L, com uma acumulação de 30,38% P(3HB) (mPHA/mX). No ensaio realizado em reator descontínuo com regulação de pH, em meio 50% (v/v) EAF, verificou-se o melhor resultado de produção, com a acumulação de 85,60 % P(3HB) mPHA/mX. H. mediterranei revelou-se incapaz de crescer significativamente em EAF. No ensaio realizado com H. mediterranei em meio sintético com 2% de glucose verificou-se uma taxa específica de crescimento máxima de 0,03 h-1, uma concentração de biomassa final de 23,66 g/L e uma acumulação de 4,89 g/L P(3HB/3HV) (17,21% mPHA/mX). O polímero produzido por H. mediterranei foi identificado como P(3HB/3HV), constituído por 90,04% HB/ 9,96% HV. Neste trabalho foi verificada pela primeira vez a adequação do EAF como meio para produção de PHAs. Estes resultados são uma contribuição valiosa no processo de valorização deste subproduto agroindustrial, e adjacente propósito de redução de custos na produção de PHAs.
The aim of this work was the valorization of the white grape skins, a byproduct of the wine industry, through the production of polyhydroxyalkanoates (PHAs) using Cupriavidus necator and Haloferax mediterranei. PHAs are intracellular polyesters stored in the cell as carbon source, with commercial value as bioplastics due to its biodegradable and biocompatible nature. Accumulation tests were carried using defined synthetic medium supplemented with glucose and mannose (main sugars in the extract) and white grape skins aqueous extract (GSAE) supplemented with mineral medium constituents. From the tests performed in erlenmeyer with C. necator in GSAE it was found that bacteria could grow to a maximum specific rate of 0.19 h-1 to a final biomass concentration of 17.11 g.L-1, with an accumulation of 30.38% P(3HB) (mPHA/mX). When production tests were performed in a batch reactor with pH regulation, using 50% (v/v) GSAE, best result of accumulation were achieved, with accumulation of 85.60% P(3HB) (mHB/mX). H. mediterranei revealed to be unable to grow significantly in GSAE. In the test with H. mediterranei in synthetic medium containing 2% glucose, there was a specific maximum growth rate of 0.03 h-1, a final biomass concentration of 23.66 g.L-1 and an accumulation of 4.89 g.L-1 P(3HB/3HV) (17.21% mPHA/mX). The polymer produced by H. mediterranei was identified as P(3HB/3HV) consisting of 90.04% HB/ 9.96% HV. This work recognizes for the first time the suitability of the GSAE as a substrate for PHA production. These results are a valuable contribution to the valorization of this agro-industrial by-product, and adjacent cost reduction in the PHA production process.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Thomas, Tatiana. "Étude du potentiel biotechnologique de Halomonas sp. SF2003 : application à la production de polyhydroxyalcanoates (PHA) Complete genome sequence of the halophilic PHA-producing bacterium Halomonas sp. SF2003: insights into its biotechnological potential PHA Production and PHA Synthases of the Halophilic Bacterium Halomonas sp. SF2003." Thesis, Lorient, 2019. http://www.theses.fr/2019LORIS542.

Повний текст джерела

Анотація:

L’amenuisement des ressources pétrochimiques couplé à la pollution engendrée par l’exploitation des plastiques posent de nombreuses questions et conduisent à un besoin urgent de solutions alternatives. Les polyhydroxyalcanoates (PHA) sont des polymères qui ont su se démarquer et naturellement s’imposer comme matériaux de remplacement, de par leurs caractères à la fois biosourcé et biodégradable. Leur synthèse par un grand nombre d’organismes procaryotes et eucaryotes, à partir d’une large gamme de substrats carbonés, rend leur production quasi illimitée et conduit à l’obtention de polymères aux propriétés allant de celles d’un thermoplastique rigide à un élastomère. Malgré cela, les rendements et les coûts de production représentent toujours les principaux verrous à leur développement. Parmi les solutions envisagées, l’exploitation de ressources marines, telles que les bactéries halophiles, suscite un fort intérêt tant les capacités d’adaptation de ces souches sont étendues et avantageuses. Halomonas sp. SF2003 est une souche marine naturellement productrice de PHA possédant une grande capacité d’adaptation face à de nombreux substrats et conditions environnementales. L’étude et l’optimisation de sa production de PHA font l’objet de ce travail. Le séquençage de son génome, couplé à des tests phénotypiques, ont permis l’étude de différents gènes et voies métaboliques confirmant son caractère adaptatif. Dans le même temps, l’influence de différents paramètres sur la production de PHA a été étudiée. Ces travaux, faisant appel à des techniques de biologie moléculaire et des bioprocédés, contribueront au développement du potentiel biotechnologique de la souche Halomonas sp. SF2003
Depletion of oil ressources coupled to pollution caused by over-exploitation of plastics generate a plentiful of issues and lead to an urgent need for alternatives. PolyHydroxyAlkanoates (PHA) are biopolymers which have distinguished and naturally imposed themselves due to their biosourcing and biodegradability features. Their synthesis by a wide variety of eukaryotic and prokaryotic organisms, from various carbon substrates, makes their production almost unlimited and allows obtaining polymers exposing rigid thermoplastic to elastomeric properties. Despite that, the production yield and the cost are still the main locks to their development. Among possibilities studied, exploitation of marine resources, like halophilic bacteria, arouse a strong interest since adaptability of these strains is extensive and attractive. Halomonas sp. SF2003 is a PHA producing marine bacterium which naturally exposes a considerable versatility in front of carbon substrates and environmental conditions. Characterization and optimization of its PHA production are the main subjects of the presented study. Genome sequencing and annotation, in addition to phenotypic tests, allowed characterization of various genes and metabolic pathways attesting of the adaptative strain character. In the same time, impact of various parameters on Halomonas sp. SF2003 PHA production has been investigated. This work, employing molecular biology and bioprocess tools, will contribute to future development of biotechnological potential of Halomonas sp. SF2003

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Gajdová, Barbora. "Identifikace PHA produkujících bakterií pomocí nástrojů molekulární biologie." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316230.

Повний текст джерела

Анотація:

This diploma thesis deals with identification of bacteria which are capable of producing polyhydroxyalkanoates (PHAs). Work included testing variety of genera including Pseudomonas, Lactobacillus, Bifidobacterium, thermophilic cultures and samples gathered from natural sources. Bacteria were investigated by molecular technique polymerase chain reaction – PCR. An amplification of the PHA synthase gene (phaC) was analyzed. In the first reaction phaC and 16S rRNA genes were tested at the same time. 16S rRNA gene is used as control for bacterial DNA and as an identification tool for natural source samples. This multiplex PCR used multiple primers in PCR mix. Second reaction search for amplicon specific for catalysing biosynthesis mcl-PHA (phaC1). The presence of the PHA synthase gene was verified in 11 samples which were Bifidobacterium breve CCM 7825T, Lactobacillus rhamnosus CCM 1825T, Lactobacillus zeae CCM 7069T, Lactobacillus delbrueckii subsp. bulgaricus CCM 7190T, Lactobacillus plantarum CCM 7039T, Pseudomonas gessardii, Pseudomonas fulva, Arthrobacter protophormiae, Curtobacterium flaccumfaciens, Mycobacterium neoaurum and Staphylococcus lentus.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Bandino, Enrico. "Assessing the impact of ammonia content in VFA-rich streams on the PHA-storing MMC acclimatization and the PHA production stage." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

Знайти повний текст джерела

Анотація:

The use of environmentally friendly products increased the interest in renewable resources as alternatives to petrochemical products. Polyhydroxyalkanoates (PHAs) are examples of such promising products, as they are biodegradable polymers with numerous potential applications. PHA production approach consists of using an open mixed microbial culture (MMC) and inexpensive feedstocks (waste or industry byproducts feedstock). The PHA process generally comprises three stages: (1) acidogenic fermentation (AF) stage (conversion of organic carbon into fermentation products); (2) culture selection stage (enrichment in PHA-storing organisms by applying Feast and Famine regime); and (3) PHA production stage (PHA accumulation up to the culture’s maximum capacity). AF of protein-rich residues results in ammonia-rich fermented streams, which can be presented as a challenge for the PHA production stage. The presence of ammonia during this stage may induce organisms to grow instead of producing PHAs. For this reason, the assessment of the effect of a high content of ammonia on PHA production it is the utmost importance. The main goal of the current project is to select a MMC enriched in PHA-accumulating organisms in conditions of high ammonia content and to evaluate the effects of ammonia presence during PHA accumulation. The culture was selected applying the Feast & Famine strategy, and fed, firstly, using a synthetic mixture of VFAs and later using a fermented stream obtained from the fermentation of protein-rich raw materials. The selected culture could accumulate up to 24% PHA per VSS with the synthetic mixture of VFAs and up to 29% for the real fermented stream. The PHA accumulation resulted in different production in the presence and absence of ammonia. Regarding to the synthetic feed, 59%wt. PHA (VSS basis) in the absence of ammonia, and 55%wt. (VSS basis) in the presence, were obtained. For the real feed, the PHA content was about 40%wt. (VSS basis) in both reactors.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Ercan, Can. "Phpa As A Frictional Pressure Loss Reducer And Its Pressure Loss Estimation." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608451/index.pdf.

Повний текст джерела

Анотація:

As the demand of oil and gas is increasing, using the existing reservoirs more efficiently as well as searching for new reservoirs is mandatory. Most undiscovered reservoirs are in deep or ultra-deep offshore locations, where drilling to such targets are very difficult with the available fluid circulation technology, since there exists a significant frictional pressure loss due to extreme long wellbores. In order to reduce the frictional pressure losses inside the drillstring, frictional drag reducers are used. Frictional drag reducers are mostly high molecular weight linear polymer molecules and can be used with water or hydrocarbon based solvents. The system used in this study is Baroid EZ-Mud water solutions. Baroid EZ-Mud is a liquid polymer emulsion containing partially hydrolyzed polyacrylamide / polyacrylate (PHPA) co-polymer. This study aims to observe the performance of EZ-Mud as a frictional drag reducer. For this purpose, a flow loop that consisted of a circular pipe where the frictional pressure losses can be observed under various flow rates and concentrations is developed. Pipe flow experiments were performed using water-based mud generated using different concentrations of Baroid EZ-Mud at different flow rates. Differential pressure values were recorded for each run. Rheological properties of each mud sample were determined using Fann (Couette) viscometer in order to determine the theoretical frictional pressure losses. Theoretical and measured frictional pressure losses were compared. Results showed that, as the concentration of EZ-Mud was increased, considerable frictional drag reduction as high as 60% was observed. Based on the experimental data obtained from the flow loop using EZ-Mud with different concentrations, a friction factor correlation as a function of Reynolds Number and EZ-Mud concentration is developed. The proposed correlation performance was also compared with the existing correlations from the literature. It has been observed that, frictional pressure losses using the developed friction factor could be estimated within an error range of maximum 15 %, whereas, the existing models could not predict frictional pressure losses as accurate as the proposed model.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Piggot, William Benjamin. "The geography of exclusion : race and suburbanization in postwar Philade[l]phia /." Columbus, Ohio : Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1166561231.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Costa, Siddhartha Georges Valadares Almeida de Oliveira [UNESP]. "Estudo da produção de metabólitos por Pseudomonas aeruginosa: Ramnolipídios e Polihidroxialcanoatos (PHAs)." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/103958.

Повний текст джерела

Анотація:

Made available in DSpace on 2014-06-11T19:32:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-20Bitstream added on 2014-06-13T21:05:14Z : No. of bitstreams: 1 costa_sgvao_dr_rcla.pdf: 982367 bytes, checksum: 52f037ca5cb5fbb958ef2b1a4f53f13c (MD5)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O presente trabalho visou estudar a produção de biossurfactante e PHAs de Pseudomonas sp. em substratos alternativos oriundos do processamento de alimentos bem como determinar as propriedades, composição química e aplicações dos compostos obtidos. Foram isoladas 21 cepas bacterianas, sendo que duas cepas demonstraram capacidade de crescer no meio de cultivo proposto e produzir ramnolipídios e PHAs. Estas cepas foram identificadas como Pseudomonas aeruginosa e receberam as seguintes terminações: P. aeruginosa L2-1 e P. aeruginosa B1-3. Com relação a caracterização de ramnolipídios e PHAs, suas composições variaram de acordo com a fonte de carbono e a linhagem utilizada na fermentação. O meio manipueira adicionado com óleo de fritura (MOF) apresentou os melhores resultados, alcançando uma produção de PHA de 39% do peso seco de células e uma produção de ramnolipídios de 660 mg/L. A manipueira se mostrou um substrato alternativo com potencial para a produção de ramnolipídios e PHAs, principalmente quando adicionada com óleo de fritura, além de ser uma solução do ponto de vista ambiental e também agregar valor a estes resíduos. A manipueira adicionada de óleo de fritura pode reduzir os custos de produção permitindo a obtenção concomitante de ramnolipídios e PHAs. O ramnolipídio produzido pela linhagem P. aeruginosa L2-1 no substrato manipueira adicionado de óleo de fritura foi recuperado e apresentou excelentes propriedades tenso-ativas, (baixos valores de concentração micelar crítica e de tensão superficial e interfacial, excelente atividade emulficante e estabilidade da emulsão), além de potencial para uso na remediação de ambientes contaminados, removendo até 89% de petróleo na areia após processo de lavagem, conferindo características semelhantes e algumas vezes melhores que o ramnolipídio comercial JBR599 (Jeneil Biosurfactant Co.)
This work evaluated the rhamnolipid and PHAs production by Pseudomonas sp. in alternative low-cost substrates from food processing, determining the properties, applications and chemistry composition of compounds obtained. Were isolated 21 strains, being that 2 isolates were able to growth and produce rhamnolipids and PHAs in the substrates. These bacteria were identified as Pseudomonas aeruginosa. The polymers and surfactants produced were characterized by gas-chromatography mass spectrophotometry (GC-MS) and by high performance liquid chromatography-MS (HPLC-MS), and their composition was found to vary with the carbon source and the strain used in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with cassava wastewater added with waste cooking oil (CWO) as the carbon source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipids production being 660 mg/L. It would appear that CWO has the highest potential as alternative substrate, and its use may contribute to a reduction in the overall environmental impact generated by discarding such residues. The rhamnolipid produced by P. aeruginosa L2-1 in CWO showed excellent tension-active properties (low values of critic micellar concentration and superficial and interfacial tensions) and potential to use in remediation of contaminated environmental, removing 89% of petroleum after washing process in sand, with characteristics similar or better than commercial rhamnolipid JBR599 (Jeneil Biosurfactant Co.)

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Paula, Fabrício Coutinho de [UNESP]. "Polihidroxialcanoatos (PHAs): bioprospecção de micro-organismos e produção a partir de glicerol." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/103963.

Повний текст джерела

Анотація:

Made available in DSpace on 2014-06-11T19:32:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-10Bitstream added on 2014-06-13T19:43:45Z : No. of bitstreams: 1 paula_fc_dr_rcla.pdf: 1312616 bytes, checksum: 37d3ba636c09c8b0df0d9d23402e492d (MD5)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os polihidroxialcanoatos (PHAs) são poliésteres biodegradáveis, sintetizados como grânulos intracelulares em células bacterianas, na presença de excesso de fonte de carbono e limitação de nutrientes necessários ao crescimento. Estes biopolímeros são atraentes substitutos para os polímeros derivados do petróleo, devido às suas propriedades similares com vários termoplásticos e elastômeros. Atualmente, a produção de biocombustíveis é outra grande alternativa para a substituiçã do petróleo, especialmente o biodiesel produzido a partir da transesterificação de gorduras e óleos vegetais e animais. O glicerol bruto é o principal subproduto da produção deste biocombustível, o qual tem baixo custo devido à presença de impurezas. O desafio na produção de PHAs é a competitividade com os preços dos polímeros derivados do petróleo. Uma solução para este problema tem sido propor a implementação de biorefinarias que obtém outros produtos, agregando valores à cadeia de produção do biodiesel, tal como, a produção de biopolímeros bacterianos, utilizando glicerol bruto como fonte de carbono. Portanto, torna-se necessária a descoberta de novas linhagens bacterianas promissoras, na produção de PHAs a partir deste insumo. Neste trabalho, realizou-se a busca por micro-organismos capazes de produzir polihidroxialcanoatos (PHAs) utilizando glicerol em meios de cultivo. Para verificar o potencial de produção destes polímeros a partir desta fonte de carbono, foram avaliadas 107 linhagens de micro-organismos através da reação com o corante Sudan Black B. Entre os quais, estavam 76 isolados obtidos de solo de Floresta Ombrófila Densa (Mata Atlântica) e 31 de solo de Mangue. Além disso, foram também avaliadas 7 linhagens de P. aeruginosa provenientes de solos contaminados com hidrocarbonetos e manipueira...
The polyhydroxyalkanoates (PHAs) are biodegradable polyesters that are synthesized intracellularly and deposited as granules in bacterial cultures in the presence of excess carbon source and a growth limiting nutrient. These biopolymers are attractive substitute for petrochemical-based plastics due to their similar material properties to various thermoplastics and elastomers. Actually, the biofuels production is another great alternative to replace the petroleum, specially the biodiesel generated from the transesterification of vegetable or animal fats and oils. The crude glycerol is the main byproduct of biodiesel production, which has a relative low value due to the presence of impurities. The challenge in the PHAs production is the competitive prices of petroleum polymers. A solution for this problem has been proposed with the implementation of biorefineries that co-produce additional valueadded products along with biodiesel, such as bacterial biopolymers production utilizing crude glycerol as a carbon source. Therefore, it is necessary to discover a new promising PHAsproducing bacterial strains. In this work, was carried out the search for PHA-producer microorganisms utilizing glycerol as a sole carbon source. For this, 107 bacterial strains were evaluated by Sudan Black B staining reaction. Among which were 76 strains isolated from a tropical moist forest soil (Atlantic forest) and 31 from Mangrove ecosystem. Furthermore, 7 P. aeruginosa strains isolated from hydrocarbon-contaminated soil and cassava wastewater were also evaluated for PHAs production. In this experiments were determined the pH, carbon source consumption e cell dry weight. The freeze-dried cells were subjected to propanolysis for PHAs determination.The propyl esters were assayed by gas chromatography... (Complete abstract click electronic access below)

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Paula, Fabrício Coutinho de. "Polihidroxialcanoatos (PHAs) : bioprospecção de micro-organismos e produção a partir de glicerol /." Rio Claro : [s.n.], 2012. http://hdl.handle.net/11449/103963.

Повний текст джерела

Анотація:

Orientador: Jonas Contiero
Banca: José Gregório Cabrera Gomez
Banca: Eloizio Júlio Ribeiro
Banca: Elisabeth Loshchagin Pizzolitto
Banca: Andre Henrique Rosa
Resumo: Os polihidroxialcanoatos (PHAs) são poliésteres biodegradáveis, sintetizados como grânulos intracelulares em células bacterianas, na presença de excesso de fonte de carbono e limitação de nutrientes necessários ao crescimento. Estes biopolímeros são atraentes substitutos para os polímeros derivados do petróleo, devido às suas propriedades similares com vários termoplásticos e elastômeros. Atualmente, a produção de biocombustíveis é outra grande alternativa para a substituiçã do petróleo, especialmente o biodiesel produzido a partir da transesterificação de gorduras e óleos vegetais e animais. O glicerol bruto é o principal subproduto da produção deste biocombustível, o qual tem baixo custo devido à presença de impurezas. O desafio na produção de PHAs é a competitividade com os preços dos polímeros derivados do petróleo. Uma solução para este problema tem sido propor a implementação de biorefinarias que obtém outros produtos, agregando valores à cadeia de produção do biodiesel, tal como, a produção de biopolímeros bacterianos, utilizando glicerol bruto como fonte de carbono. Portanto, torna-se necessária a descoberta de novas linhagens bacterianas promissoras, na produção de PHAs a partir deste insumo. Neste trabalho, realizou-se a busca por micro-organismos capazes de produzir polihidroxialcanoatos (PHAs) utilizando glicerol em meios de cultivo. Para verificar o potencial de produção destes polímeros a partir desta fonte de carbono, foram avaliadas 107 linhagens de micro-organismos através da reação com o corante Sudan Black B. Entre os quais, estavam 76 isolados obtidos de solo de Floresta Ombrófila Densa (Mata Atlântica) e 31 de solo de Mangue. Além disso, foram também avaliadas 7 linhagens de P. aeruginosa provenientes de solos contaminados com hidrocarbonetos e manipueira... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The polyhydroxyalkanoates (PHAs) are biodegradable polyesters that are synthesized intracellularly and deposited as granules in bacterial cultures in the presence of excess carbon source and a growth limiting nutrient. These biopolymers are attractive substitute for petrochemical-based plastics due to their similar material properties to various thermoplastics and elastomers. Actually, the biofuels production is another great alternative to replace the petroleum, specially the biodiesel generated from the transesterification of vegetable or animal fats and oils. The crude glycerol is the main byproduct of biodiesel production, which has a relative low value due to the presence of impurities. The challenge in the PHAs production is the competitive prices of petroleum polymers. A solution for this problem has been proposed with the implementation of biorefineries that co-produce additional valueadded products along with biodiesel, such as bacterial biopolymers production utilizing crude glycerol as a carbon source. Therefore, it is necessary to discover a new promising PHAsproducing bacterial strains. In this work, was carried out the search for PHA-producer microorganisms utilizing glycerol as a sole carbon source. For this, 107 bacterial strains were evaluated by Sudan Black B staining reaction. Among which were 76 strains isolated from a tropical moist forest soil (Atlantic forest) and 31 from Mangrove ecosystem. Furthermore, 7 P. aeruginosa strains isolated from hydrocarbon-contaminated soil and cassava wastewater were also evaluated for PHAs production. In this experiments were determined the pH, carbon source consumption e cell dry weight. The freeze-dried cells were subjected to propanolysis for PHAs determination.The propyl esters were assayed by gas chromatography... (Complete abstract click electronic access below)
Doutor

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Costa, Siddhartha Georges Valadares Almeida de Oliveira. "Estudo da produção de metabólitos por Pseudomonas aeruginosa : Ramnolipídios e Polihidroxialcanoatos (PHAs) /." Rio Claro : [s.n.], 2010. http://hdl.handle.net/11449/103958.

Повний текст джерела

Анотація:

Resumo: O presente trabalho visou estudar a produção de biossurfactante e PHAs de Pseudomonas sp. em substratos alternativos oriundos do processamento de alimentos bem como determinar as propriedades, composição química e aplicações dos compostos obtidos. Foram isoladas 21 cepas bacterianas, sendo que duas cepas demonstraram capacidade de crescer no meio de cultivo proposto e produzir ramnolipídios e PHAs. Estas cepas foram identificadas como Pseudomonas aeruginosa e receberam as seguintes terminações: P. aeruginosa L2-1 e P. aeruginosa B1-3. Com relação a caracterização de ramnolipídios e PHAs, suas composições variaram de acordo com a fonte de carbono e a linhagem utilizada na fermentação. O meio manipueira adicionado com óleo de fritura (MOF) apresentou os melhores resultados, alcançando uma produção de PHA de 39% do peso seco de células e uma produção de ramnolipídios de 660 mg/L. A manipueira se mostrou um substrato alternativo com potencial para a produção de ramnolipídios e PHAs, principalmente quando adicionada com óleo de fritura, além de ser uma solução do ponto de vista ambiental e também agregar valor a estes resíduos. A manipueira adicionada de óleo de fritura pode reduzir os custos de produção permitindo a obtenção concomitante de ramnolipídios e PHAs. O ramnolipídio produzido pela linhagem P. aeruginosa L2-1 no substrato manipueira adicionado de óleo de fritura foi recuperado e apresentou excelentes propriedades tenso-ativas, (baixos valores de concentração micelar crítica e de tensão superficial e interfacial, excelente atividade emulficante e estabilidade da emulsão), além de potencial para uso na remediação de ambientes contaminados, removendo até 89% de petróleo na areia após processo de lavagem, conferindo características semelhantes e algumas vezes melhores que o ramnolipídio comercial JBR599 (Jeneil Biosurfactant Co.)
Abstract: This work evaluated the rhamnolipid and PHAs production by Pseudomonas sp. in alternative low-cost substrates from food processing, determining the properties, applications and chemistry composition of compounds obtained. Were isolated 21 strains, being that 2 isolates were able to growth and produce rhamnolipids and PHAs in the substrates. These bacteria were identified as Pseudomonas aeruginosa. The polymers and surfactants produced were characterized by gas-chromatography mass spectrophotometry (GC-MS) and by high performance liquid chromatography-MS (HPLC-MS), and their composition was found to vary with the carbon source and the strain used in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with cassava wastewater added with waste cooking oil (CWO) as the carbon source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipids production being 660 mg/L. It would appear that CWO has the highest potential as alternative substrate, and its use may contribute to a reduction in the overall environmental impact generated by discarding such residues. The rhamnolipid produced by P. aeruginosa L2-1 in CWO showed excellent tension-active properties (low values of critic micellar concentration and superficial and interfacial tensions) and potential to use in remediation of contaminated environmental, removing 89% of petroleum after washing process in sand, with characteristics similar or better than commercial rhamnolipid JBR599 (Jeneil Biosurfactant Co.)
Orientador: Jonas Contiero
Coorientador: Marcia Nitschke
Banca: José Gregório Cabrera Gomez
Banca: Marcos Rogério Tótola
Banca: Humberto Márcio Santos Milagre
Banca: Lucia Regina Durrant
Doutor

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Trébuil, Guy. "Sathing Phra : un système agraire en crise au sud de la Thaïlande." Paris, Institut national d'agronomie de Paris Grignon, 1987. http://www.theses.fr/1987INAPA010.

Повний текст джерела

Анотація:

La recherche des causes de la faible adoption des techniques rizicoles de la revolution verte dans le district de sathing phra conduit a l'analyse detaillee du systeme agraire local au moyen d'une approche globale, systemique et historique: genese et caracteres originaux du mode traditionnel d'artificialisation de l'ecosysteme (en particulier l'association riz-palmier a sucre), fonctionnement et typologie des principaux systemes de production agricole, analyse et performance des principaux itineraires techniques paysans

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Ticona, Chambi Wilma Gladis. "Caracterización química, mineralógica estructural de tres arcillas (ph`asas) de la región altiplática boliviana: hacia una visión científica en su aplicación tradicional." Universidad Mayor de San Andrés. Programa Cybertesis BOLIVIA, 2008. http://www.cybertesis.umsa.bo:8080/umsa/2008/ticona_cw/html/index-frames.html.

Повний текст джерела

Анотація:

La presente tesis desarrolla la caracterización química, mineralógica y estructural de tres arcillas. Estás en general son conocidas con el nombre de “ph’asas”, p'asa, pasa, ppassa, pahsa, p'asalla en el lengua aymará siendo ampliamente utilizadas por lo médicos ”kallawayas”, por sus propiedades particulares que poseen, en el campo de la medicina tradicional boliviana y como alimento en especial en la región altiplánica de Bolivia. Dos de estás ph’asas corresponden a la localidad de Achocalla (Departamento de La Paz) y otra de la localidad de Andamarka (Departamento de Oruro), Bolivia. La caracterización geológica revela como fase mayoritaria (casi única) aluminosilicatos hidratados de K, Mg, Ca y Fe que corresponden a minerales del grupo de las Esmectitas en su especie Montmorillonita, identificándose como impurezas feldespatos para las muestras de La Paz y sílice tipo Cuarzo y Cristobalita en la de Oruro. La caracterización estructural en relación a la caracterización química, revela que las dos muestras de La Paz presentan una alta similitud, dado que el origen geomorfológico es similar, por otro lado estos productos son materiales arcillosos tipo Montmorillonita de carácter sódico, frente a la muestra de Oruro, que es también una Montmorillonita pero de carácter cálcico. Está diferencia elemental en su composición estructural, influye fundamentalmente en las propiedades físico – químicas de las muestras, favoreciendo para el caso de las muestras sódicas sus capacidades de: absorción de moléculas orgánicas (específicamente etilenglicol) o agua (en este ultimo caso una mayor tendencia a la hidratación e hinchamiento – pasando por la gelificación) y neutralización de un medio ácido. En la muestra de Oruro su capacidad para estás propiedades es reducida por su carácter Cálcico. La caracterización química ha sido desarrollada utilizando los resultados obtenidos mediante el análisis por IPC-plasma, Fluorescencia de rayos X (FRX), la estructural por Difracción de rayos X (DRX), Microscopia Electrónica de Barrido (SEM) e Infrarrojo (IR) y las propiedades fisicoquímicas utilizando un pH metro y espectroscopia de Absorción Atómica (AA). La arcilla de la localidad de Achocalla –La Paz presenta mejores características para la aplicación tradicional. Finalmente se presenta las conclusiones del trabajo y sugerencias según sus propiedades, que se propone para futuras experiencias relacionadas.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Ligny, Romain. "Nouveaux (co)polyesters à séquences contrôlées par catalyse de polymérisation stéréosélective." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S110/document.

Повний текст джерела

Анотація:

Les poly(hydroxyalcanoate)s (PHAs) sont des polyesters biodégradables et biocompatibles d'intérêt pour leur application dans le domaine biomédical ou en substitution des plastiques dérivés de l'industrie pétrolière. La synthèse des PHAs par polymérisation par ouverture de cycle (ROP) de monomères cycliques, les β-lactones, permet un bon contrôle de la masse molaire, de la microstructure et de la fonctionnalité des polymères. Les propriétés des polyesters peuvent être modulées par l'utilisation de différents monomères. Depuis quelques décennies, différents PHAs ont été synthétisés, notamment le poly(hydroxybutyrate) (PHB) et les poly(malolactonate d'alkyle)s (PMLARs). Ces travaux ont été étendus à la ROP d'une nouvelle famille de β-lactones, les 4- alcoxyméthlylène-β-propiolatones (BPLORs). Ainsi, différents systèmes catalytiques à base d'yttrium offrent des (co)polymères de tacticité (syndiotactique, atactique ou isotactique) et de topologie (copolymères à blocs, alternés ou aléatoires) originales. La stéréosélectivité des systèmes catalytiques mis en œuvre est inédite dans le contexte scientifique actuel. En effet, la nature des substituants des ligands ancillaires des complexes d'yttrium permet de moduler la microstructure et donc les propriétés des PHAs obtenus
Poly(hydroxyalkanoate)s (PHAs) are biodegradable and biocompatible polyesters of interest for their application in the biomedical field or as alternative to plastics derived from the petroleum industry. The synthesis of PHAs by ring-opening polymerization (ROP) of cyclic monomers, β-lactones, enables a good control of the molar mass, the microstructure and the functionality of the polymers. The properties of the polyesters can be tuned by the using different monomers. In recent decades, various PHAs have been synthesized, in particular poly(hydroxybutyrate) (PHB) and poly(alkyl malolactonate)s (PMLARs). This work has been extended to the ROP a new family of β-lactones, namely 4-alkoxymethlylene-β-propiolatones (BPLORs). Thus, various yttrium-based catalyst systems provide (co)polymers with original tacticity (syndiotactic, atactic or isotactic) and topology (block, alternating or random copolymers). The stereoselectivity of the catalytic systems implemented is unprecedented in the current scientific context. Indeed, the nature of the substituants on the ancillary ligand of the yttrium complexes enables to tune the microstructure and therefore the properties of the resulting PHAs

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Linha, Vojtěch. "Příprava a aplikace nanovláken a nanočástic na bázi PHA." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-318127.

Повний текст джерела

Анотація:

The goal of this thesis was to summarize basic options of fiber spinning and manufacturing and their usability in industry. Methods of nanofiber spinning are described in the teoretical part, alongside the materials used in experimental part. The experimental part was focused on creating of workflow of defined nanofibers in laboratory enviroment, the possible modification of nanofibers with aditives. The release of aditives from different nanofibers into different enviroments was measured.

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "PHSA"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями