Дисертації з теми "Bacteria accumulation"
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Goddard, P. A. "Metal accumulation in bacteria." Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373881.
Повний текст джерелаSabeti, Azad Mahnaz. "Accumulation of a bactericidal antibiotic by tolerant bacteria and insights into bacterial persistence." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS585.
Повний текст джерелаAminoglycoside (AG) is a family of antibiotic which target bacterial ribosome. Few examples of this family are neomycin, gentamicin and streptomycin. When these antibiotics bind to ribosomes, they cause miscoding or inhibit protein synthesis which consequently leads to cell death. Although discovery of these antibiotics was more than half a century ago, there are many facts about AGs’ action mechanism which remain unknown. AG accumulation in the bacterial cells happens in three steps. First step is cell membrane attachment. This step is driven by an electrostatic interaction with the cationic AGs. Second step is an energy dependent phase I (EDPI). In EDPI, the antibiotic enters into the cytoplasm and reaches ribosomes, causing miscoding and production of misfolded proteins. EDPI depends on cellular energy level, however to date the mechanism by which AGs pass through membranes and enter cytoplasm is unknown. The third step is energy dependent phase II (EDPII) in which the antibiotic enters into the cytoplasm in larger amount due to damages in the membrane that resulted from EDPI. The aim of this PhD was to create new tools to study the interaction of AGs with bacteria and apply the methodology to study fast growing bacteria as well as persister cells. We have made fluorescently-tagged AGs with preserved bactericidal properties. We used these conjugates to track down the interaction of AG at single cell level by fluorescence microscopy. We combined fluorescence microscopy and fluorescence-activated cell sorting (FACS) analysis to measure AGs accumulation in the cells at different time points to capture the kinetics of antibiotic penetration. This study showed that there are two accumulations patterns for the drug in cells: in the first step there is a peripheral accumulation, which corresponds to specific binging to cell membrane. Next there is a cytoplasmic accumulation in which the antibiotic in entering into the cytoplasm. According to microscopy time laps study, low levels of cytoplasmic accumulation is tolerated by cells and did not cause cell death. Using FACS analysis, we used an inhibitor of EDPI and EDPII and proved that with this technique we can distinguish different steps of AGs accumulation. During protocol adjustment steps we found that AGs can enter into the cytoplasm as a result of mechanosensation and activation of mechanosensitive (MS) channels. These channels have already been shown to have affinity to AG and here this is a first time that we observed that mechanical manipulation of cells lead to opening of MS channel causing massive cytoplasmic accumulation. This unpredictable result may lead us to a better understanding of the mechanism of AG entrance into the cytoplasm. After studying AG accumulation in fast growing cells, we studied AG tolerance for non-growing cells, which are called persisters. Persisters are antibiotic tolerant sub-population among susceptible bacterial cell population. Persisters are non-growing, dormant cells which tolerate high concentrations of antibiotic. In the absence of antibiotic, they exit this dormant state and grow into an antibiotic susceptible population. By fluorescence microscopy we showed that persister cells have peripheral accumulation of AG. Thanks to our methodology, we have a powerful tool by which we can determine the patterns of AG accumulation. Prior to this study, it was only possible to know the levels of accumulation and not the corresponding patterns. We applied the method to investigate AG accumulation in two mutants of E. coli, which are less tolerant to AG and defined their pattern of accumulation. Finally, we developed a coated microfluidic system, which is adapted to our antibiotics for studying in real time drug accumulation by persister cells
Lopez, Hector Matias. "Influence of the coupling between flow and bacteria on the fluid rheology and on bacterial transport." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112168.
Повний текст джерелаThe question of transfer and spreading of living microorganisms, such as motile bacteria, is of interest in biology and ecology, but also in engineering and medicine.The way in which the background flow affects the behavior of these bacteria and how it impacts the bacterial transport through complex systems and on the macroscopic properties of the fluid remains unclear and little studied.In this thesis, I present an experimental investigation of the coupling between the local bacteria-driven motion and the fluid advection.In a first part, I investigate the rheological response of E. coli suspensions when subjected to weak flows (low shear rates). I show that, in particular conditions, the microscopic perturbations caused by the bacteria highly impact on the macroscopic viscosity of the suspension, leading to a striking viscosity decrease and eventually overcoming the dissipative effects due to viscous loss. I also identify the relevant time scales defining this viscosity decrease.In a second part, I perform experiments in a capillary channel and analyze the coupling for stronger flows (higher shear rates), at which bacteria were found not to impact on the macroscopic viscosity. Instead, by analyzing the bacterial trajectories under flow, I evidence a breakage of the symmetry of this trajectories which, characterized by a preferential migration, causes the localization of the bacteria in a layer that extends over a significant distance from the surface, and thus potentially influencing the bacterial transport in complex systems
Koo, S. P. "Regulation of compatible solute accumulation in enteric bacteria by osmotic stress." Thesis, University of Aberdeen, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.592900.
Повний текст джерелаDavies, Giddings Egba Arikpo. "Heavy metal accumulation by the green alga Chlorella emersonii." Thesis, London South Bank University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336421.
Повний текст джерелаZhao, Hui. "Inhibition of Fusarium Growth and Trichothecene Accumulation in Grain by Antifungal Compounds from Lactic Acid Bacteria." Diss., North Dakota State University, 2013. https://hdl.handle.net/10365/26870.
Повний текст джерелаDurand, Alexis. "Diversité et caractérisation fonctionnelle des communautés microbiennes inféodées au peuplier et issues d'une friche industrielle enrichie en mercure." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD037/document.
Повний текст джерелаSoil has a natural capital that gives it the capacity to produce ecosystem services, cultural as well as regulation or supply, it is essential to the Life as we know it and the development of human activities. However, anthropogenic activities and pollution, in particular by trace elements (ETs) such as mercury (Hg), disrupt the soil and modify in depth the organization of ecosystems. Facing these challenges, remediation and management projects for polluted sites and soils have emerged during the last decades with a view to future re-exploitation of these soils. This thesis is part of the ANR-BIOFILTREE and EC2CO FREIDI-Hg projects managed by the Chrono-Environnement laboratory. My Ph-D work explored the diversity of microorganism communities associated with a poplar plantation at a Hg-contaminated site managed by phytomanagement, combining approaches such as very high-throughput sequencing and conventional culture-based techniques. These combined methods revealed i) the diversity of the bacterial and fungal communities of the poplar plantation; ii) the groups of microorganisms particularly resistant to Hg (Trichoderma and Pseudomonas); and iii) plant growth promoting bacteria (PGPB). In addition, understanding the cellular mechanisms related to the accumulation of Hg by microorganisms was one of my objectives carried out in collaboration with the LIEC (University of Lorraine). The eukaryotic models Saccharomyces cerevisiae and Podospora anserina were used to test the potential role of some ion transporters in the entry of Hg into fungal cells. The results showed that the magnesium transporter Alr1 located on the plasma membrane could participate in the transport of Hg. In addition, a transcriptomic approach in Saccharomyces cerevisiae after a short exposure to Hg of mutant and wild strains has been implemented. To conclude, this work aims to be a reference work for future phytomanagement projects in Hg-contaminated environments, which highlights micro-organism communities and their fundamental roles
Rahman, Aminur. "Bioremediation of Toxic Metals for Protecting Human Health and the Ecosystem." Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51436.
Повний текст джерелаFerreira, 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 джерелаPolyhydroxyalkanoates (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.
Sgobi, Murilo Augusto [UNESP]. "Acúmulo de matéria seca, extração e exportação de nutrientes de cultivares de trigo inoculados com Azospirillum brasilense." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/148817.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Inocular sementes de trigo com a bactéria Azospirillum brasilense pode propiciar a fixação biológica de nitrogênio (FBN), porém tem sido observado efeito mais pronunciado desta inoculação no crescimento inicial de plantas, assim, com o sistema radicular mais desenvolvido, a absorção de nutrientes e água pode ser maior. Com isso, o crescimento, produtividade e exportação de nutrientes da cultura do trigo podem ser maiores, porém a resposta a esta inoculacao pode variar conforme a afinidade da bacteria com os cultivares de trigo. Dessa forma, objetivou-se avaliar o acúmulo de matéria seca e extração de nutrientes em estádios fenológicos, exportação de nutrientes pelos grãos, componentes de produção e produtividade de grãos de cultivares de trigo inoculados ou não com Azospirillum brasilense. O experimento foi desenvolvido em Selvíria - MS, em um Latossolo Vermelho Distroférrico de textura argilosa, em sistema plantio direto. O delineamento experimental foi em blocos ao acaso com quatro repetições, com os tratamentos dispostos em esquema fatorial 3 x 2, sendo três cultivares de trigo (CD 116, IPR CATUARA TM e IAC 385), com ou sem inoculação de sementes por Azospirillum brasilense (300 ml ha-1 do produto, com estirpes Abv5 e Abv6 (garantia de 2x108 UFC mL-1). Procedeu-se também a análise de regressão em esquema de parcela subdividida com quatro repetições, em que as parcelas foram constituídas pelos seis tratamentos descritos acima, e as subparcelas no tempo, por sete épocas de coletas de plantas (antes do afilhamento, afilhamento e antes da adubação nitrogenada de cobertura, folha bandeira, emborrachamento, florescimento, grão pastoso e maturação fisiológica), para o acúmulo de matéria seca e extração de nutrientes. A inoculação com Azospirillum brasilense propiciou maior índice de clorofila foliar (ICF) e acúmulo de matéria seca de raízes, independentemente do cultivar de trigo. Os cultivares de trigo extraíram quantidades totais de nutrientes semelhantes, porém a extração por tonelada de grãos produzida foi diferenciada para K, Mg, S, B, Cu, Mn e Zn. A extração de nutrientes total ou por tonelada de grãos produzida em ordem decrescente foi de N>K>P>S>Ca>Mg>Fe>Mn>Zn≥B>Cu, com ou sem a inoculação com Azospirillum brasilense. As maiores exportações totais de K, Ca, Mg, S e Mn foram obtidas sem a inoculação com Azospirillum brasilense, entretanto, esta bactéria diazotrófica proporcionou maiores exportações de N, P, K, Ca e Mg por tonelada de grãos produzida e de Zn total. As maiores exportações relativas (acima de 50% do que é extraído) foram de Zn, Cu, P, N e B e de Mg apenas com a inoculação. O cultivar CD 116 foi o mais produtivo e que propiciou as maiores exportações totais de nutrientes, apesar da menor absorção de K, Mg, S, Cu, Mn e Zn por grãos produzido em relação aos demais cultivares. A inoculação com Azospirillum brasilense interfere de forma diferenciada nos cultivares de trigo, sendo que o cultivar CD 116 proporcionou a maior produtividade de grãos quando inoculado.
Wheat seeds inoculated with Azospirillum brasilense bacteria can provide biological nitrogen fixation (BNF), but has been observed more pronounced effect of this inoculation in the initial plant growth (phytohormonal effect), thereby, with the further development of root system, the nutrients and water uptake may be greater. Thus, the growth, productivity and nutrients removal from the wheat crop may be higher, but the response to this inoculation may vary according to the affinity of the bacterium with the wheat cultivars. The aim of this study was to evaluate the dry matter accumulation the accumulation of dry matter and nutrients uptake at different growth stages, nutrients export by grains, yield components and grains yield of wheat cultivars inoculated or not with Azospirillum brasilense. The experiment was conducted in Selvíria - MS, in a distroferric Oxisol clayey in no-till system. The experimental design was a randomized block with four replications, with the treatments arranged in a factorial 3 x 2, with three wheat cultivars (CD 116, IPR CATUARA TM and IAC 385) with or without seed inoculation by Azospirillum brasilense (300 ml ha-1 product with strains Abv5 Abv6 (2x108 guarantee UFC mL-1). Also proceeded regression analysis in a split plot scheme with four replications, where the plots were the six treatments described above, and the subplots, seven plants collections seasons (before of tillering, tillering and before nitrogen topdressing, leaf flag, booting, flowering, doughy grain and physiological maturity), for the accumulation of dry matter, extraction and export of nutrients. Azospirillum brasilense inoculation provided greater leaf chlorophyll index (LCI) and accumulation of roots dry matter, regardless of the wheat cultivar. The wheat cultivars uptake similar total amounts of nutrients, but the uptake per ton of grain produced was differentiated for K, Mg, S, B, Cu, Mn and Zn. Total nutrient extraction or per ton of grain produced in descending order was N>K>P>S>Ca>Mg>Fe>Mn>Zn>B>Cu, with or without inoculation with Azospirillum brasilense. The highest total removal of K, Ca, Mg, S and Mn were obtained without inoculation with Azospirillum brasilense; however, this diazotrophic bacterium provided higher removal of N, P, K, Ca and Mg per ton of grain produced and Zn total. The highest relative removal (above 50% that is uptake) was the Zn, Cu, P, N and B and Mg only with inoculation. The CD 116 cultivar was the most productive and provided the highest total nutrients removal, despite the lower uptake of K, Mg, S, Cu, Mn and Zn by grains produced in relation to the other cultivars. The inoculation with Azospirillum brasilense interferes differently in wheat cultivars, and cultivar CD 116 obtained the highest grain yield when inoculated.
Sgobi, Murilo Augusto. "Acúmulo de matéria seca, extração e exportação de nutrientes de cultivares de trigo inoculados com Azospirillum brasilense /." Ilha Solteira, 2016. http://hdl.handle.net/11449/148817.
Повний текст джерелаResumo: Inocular sementes de trigo com a bactéria Azospirillum brasilense pode propiciar a fixação biológica de nitrogênio (FBN), porém tem sido observado efeito mais pronunciado desta inoculação no crescimento inicial de plantas, assim, com o sistema radicular mais desenvolvido, a absorção de nutrientes e água pode ser maior. Com isso, o crescimento, produtividade e exportação de nutrientes da cultura do trigo podem ser maiores, porém a resposta a esta inoculacao pode variar conforme a afinidade da bacteria com os cultivares de trigo. Dessa forma, objetivou-se avaliar o acúmulo de matéria seca e extração de nutrientes em estádios fenológicos, exportação de nutrientes pelos grãos, componentes de produção e produtividade de grãos de cultivares de trigo inoculados ou não com Azospirillum brasilense. O experimento foi desenvolvido em Selvíria - MS, em um Latossolo Vermelho Distroférrico de textura argilosa, em sistema plantio direto. O delineamento experimental foi em blocos ao acaso com quatro repetições, com os tratamentos dispostos em esquema fatorial 3 x 2, sendo três cultivares de trigo (CD 116, IPR CATUARA TM e IAC 385), com ou sem inoculação de sementes por Azospirillum brasilense (300 ml ha-1 do produto, com estirpes Abv5 e Abv6 (garantia de 2x108 UFC mL-1). Procedeu-se também a análise de regressão em esquema de parcela subdividida com quatro repetições, em que as parcelas foram constituídas pelos seis tratamentos descritos acima, e as subparcelas no tempo, por sete épocas de c... (Resumo completo, clicar acesso eletrônico abaixo)
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Richter, Robert [Verfasser]. "Predicting bacterial accumulation of anti-infectives by measuring permeability across surrogates of the Gram-negative bacterial cell envelope / Robert Richter." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1227925352/34.
Повний текст джерелаBauda, Pascale BLOCK JEAN CLAUDE. "ACCUMULATION ET TOXICITE DU CADMIUM CHEZ LES BACTERIES GRAM NEGATIVES : ROLE DES ENVELOPPES BACTERIENNES /." [S.l.] : [s.n.], 1986. ftp://ftp.scd.univ-metz.fr/pub/Theses/1986/Bauda.Pascale.SMZ8603.pdf.
Повний текст джерелаConrady, Deborah. "The role of zinc-dependent intercellular adhesion in biofilm formation in Staphylococcus epidermidis." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1275920539.
Повний текст джерелаVadari, Yoganand. "Estimation of Microbial Diversity in Poultry Litter Using Terminal Restriction Fragment Length Polymorphism and Isolation of Phosphate Accumulating Bacteria from Poultry Litter." TopSCHOLAR®, 2004. http://digitalcommons.wku.edu/theses/239.
Повний текст джерелаWu, Yu-Sheng, and 吳育昇. "Application of Shift-Down Phenomenon in PHAs Accumulation Bacteria Screening and Fermentation Production." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59855681936854495124.
Повний текст джерела高苑科技大學
化工與生化工程研究所
100
Polyhydroxyalkanoates (PHAs), one of the biodegradable biosynthetic polymers were function as carbon and energy reservoirs in numerous bacteria. They were known to accumulate inside the bacteria usually when carbon source is excess and one else essential growth nutrient is limited. Shift-down, a temporary unbalanced bacteria culture method established by simple dilution culture procedure can equivalently induce the PHAs accumulation. A temporary unbalanced bacteria growth phenomenon established by shift-down culture procedure was applied to screening PHAs accumulating environment bacteria isolates. The culture method was applied to test PHAs accumulating in standard and environment bacteria isolates. Despite the typical limiting nutrient or C/N ratio, PHAs accumulation seems to be common in bacteria applied of the culture method. This result shown that the shift-down culture method is simple and broad spectrum in screening environment bacteria to find new industry available PHAs produced candidates. The products were characterized as PHB in recovery of Pseudomonas sp. and Bacillus sp.0.03 g/L and 0.07g/L respectively.
Li, Hsiu-Ping. "Roles of Naturally Occurring Bacteria in Controlling Iodine-129 Mobility in Subsurface Soils." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11637.
Повний текст джерелаKim, Shin-Hee. "Identification of bacteria crucial to histamine formation and monitoring their occurrence and histamine accumulation in scombroid fish." Thesis, 2001. http://hdl.handle.net/1957/25939.
Повний текст джерелаGraduation date: 2002
Hsieh, Shu-Ping, and 謝舒萍. "The study of polyhydroxyalkanoate accumulation in marine bacteria Paracoccus stylophorae KTW-16 and the cloning of the PHA synthase gene." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/44999840767248177832.
Повний текст джерела國立高雄海洋科技大學
海洋生物技術研究所
100
The marine bacterium, Paracoccus stylophorae KTW-16, was isolated from the coral Stylophora pistillata, collected from the Kenting sea waters southern Taiwan. In the marine broth (MB) without extra carbon source, P. stylophorae KTW-16 was capable of synthesizing 80 mol% 3-hydroxybutyrate (3-HB) and 20 mol% 3-hydroxyvalerate (3-HV) of PHA copolymer. At 25oC, P. stylophorae KTW-16 accumulated 30% PHA with 75 mol% 3-HB and 25 mol% 3-HV. The 3-HV monomer composition of PHA was decreased with the increase of tryptone in MB. According to this result, the effect of amino acid supplemented to the MB on PHA accumulation was tested. The addition of threonine, valine, and isoleucine significantly enhanced the 3-HV monomer composition. In addition, under the presence of β-oxidation pathway inhibitor acrylic acid in the medium, P. stylophorae KTW-16 synthesized 3-HB, 3-HV and 3-hydroxyhexanoate (3-HHx) terpolymer. The polymer structure was by nuclear magnetic resonance spectroscopy (13C-NMR) analyzed. It confirmed that three monomers were randomly copolymerized. This study also constructed a genomic library of P. stylophorae KTW-16. The PHA synthase gene was cloned. The in vivo substrate specificity of PHA synthase of P. stylophorae KTW-16 was analyzed in the PHA mutant Pseudomonas putida GPp104 PHA-. The PHA synthase of P. stylophorae KTW-16 biosynthesis 80 mol% 3-HB, 18 mol% 3-HHx and 2 mol% 3-hydroxyoctanoate (3-HO) of PHA from 0.4% octanoate as the carbon source, compared with that of Ralstonia eutropha H16 (PhaCH16) synthesizing 96 mol% 3-HB, 3 mol% 3-HHx and 1 mol% 3-HO of PHA. The above results strongly suggested that the PHA synthase of P. stylophorae KTW-16 was of broader substrate specificity than PhaCH16.
Ansiães, Márcia Filipa Carrilho. "Development and optimization of tungsten-accumulator bacteria as biotools for raw materials recovery." Master's thesis, 2018. http://hdl.handle.net/10316/86271.
Повний текст джерелаDiversas actividades antropogénicas libertam metais no meio ambiente, o que se tem vindo a tornar um problema grave. Microorganismos modificados podem ser usados como ferramentas promissoras de biorremediação para limpar áreas contaminadas por metais. O tungstênio (W) é um elemento de transição, com alta densidade que é usado em várias indústrias em todo mundo. Alguns microorganismos têm a capacidade de utilizar esse elemento como cofator para enzimas. Eles são capazes de transportar W para dentro das células usando o transportador de tungstênio altamente específico tupABC, que é constituído pela TupA (proteína de ligação W), TupB (proteína formadora de poros transmembranares) e TupC (ATPase periplasmática). Neste estudo, o grupo de genes tupABC da estirpe Sulfitobacter dubius NA4 foi usado para realizar várias construções genéticas na estirpe Escherichia coli DH5α. Foram construídos cinco clones diferentes, tupA_1 (gene completo tupA), tupA_2 (tupA sem sequência de endereçamento), tupA_3 (tupA com sequência de endereçamento do gene ompA), tupBC e tupBCA. Todos os clones foram testados quanto à capacidade de absorção de tungstênio, molibdênio (Mo) e crómio, utilizando diferentes métodos de quantificação de metais. A técnica de ICP-MS foi utilizada como abordagem padrão para a quantificação de W e Mo e os métodos DPC adaptado e ácido tânico foram utilizados como métodos espectrofotométricos para quantificação de W e Mo, respectivamente. O método DPC padrão foi usado para quantificação de cromato. Neste trabalho, concluímos que o clone tupBCA apresentou a maior capacidade de absorção W e Mo quando comparado com os outros clones. Embora a sua capacidade fosse mais relevante para W do que para o Mo. Em conclusão, estes resultados confirmaram que o sistema tupABC é o principal mecanismo de transporte de W para as células e a presença da proteína de ligação ao W é essencial para melhorar a absorção de W pelas células bacterianas. Em relação às técnicas alternativas para quantificação de W e Mo, ambos os métodos espectrofotométricos foram úteis na quantificação de metais, embora tenham mostrado algumas limitações, como a baixa sensibilidade à concentração de metais.
Several anthropogenic activities have released metals in the environment, which has become a serious issue. Modified microorganisms can be used as promising bioremediation tools to clean metal contaminated areas. Tungsten (W) is a transition element, with a high density that is used in several industries around the world. Some microorganisms have the capacity to use this element as cofactor in their enzimes. They are able to transport W into the cells using the highly specific tungsten transporter tupABC, which is constituted by the TupA (W binding protein), TupB (transmembrane pore forming protein) and TupC (periplasmatic ATPase). In this study the tupABC gene cluster of strain Sulfitobacter dubius NA4 was used to perform several genetic constructions in the strain Escherichia coli DH5α. Five different clones were constructed, tupA_1 (tupA full gene), tupA_2 (tupA without addressing sequence), tupA_3 (tupA with ompA gene addressing sequence), tupBC and tupBCA. All the clones were tested to tungsten, molybdenum (Mo) and chromium uptake capability using different metal quantification methods. ICP-MS was used as the standard approach for W and Mo quantification and the adapted DPC and the tannic acid methods were used as spectrophotometric methods for W and Mo quantification, respectively. The standard DPC method was used for chromate quantification. In this work, we concluded that clone tupBCA showed the highest ability to accumulate W and Mo when compared with the other clones. Though its capability was more relevant for W than Mo. In conclusion, these results confirmed that the tupABC system is the main W-transport mechanism to the cells and the presence of the W-binding protein is essential to improve the W uptake by bacterial cells. Moreover, in regard of the alternative techniques for W and Mo quantification, both spectrophotometric methods were useful in metal quantification, although they had shown some limitations, such as their low metal concentration sensitivity.
Atkinson, Blaise William. "Identification of polyphosphate accumulating bacteria from pilot- and full scale nutrient removal activated sludges." Thesis, 1999. http://hdl.handle.net/10321/1923.
Повний текст джерелаGeneral removal of phosphorus (P) from wastewater was introduced in Scandanavia in the late 1960's. At that time it was believed that P alone was limiting to algal growth and that the sole removal of P would solve the problem of eutrophication. However, we now know that both P and nitrogen (N) contribute to this deleterious effect and as such, much research has been conducted concerned with both the biological and chemical removal of these nutrients from sewage effluents. Enhanced biological phosphorus removal (EBPR), which is basically the biological accumulation of soluble P (as polyphosphate or poly-P) from the bulk liquid in excess of normal metabolic requirements, still tends to be sensitive to many external parameters and, as such, is subject to fluctuations. This makes it extremely difficult for wastewater treatment installations to achieve and maintain full compliance with strict discharge regulations. A more comprehensive understanding of the microbial community within the mixed liquor of a wastewater treatment system is therefore required which will ultimately assist in improving system design and performance. Chemical and civil engineers, when designing biological wastewater treatment systems, consider only the processes (biological or chemical) taking place within the reactor/s with little or no regard for the individual microbial species or the entire microbial community involved. Process design appears to be tackled empirically from a 'black box' approach; biological reactions or processes occurring within a system such as wastewater treatment are all lumped together and attributed to a single surrogate organism ie., the response of the surrogate to certain stimuli accounts for the total system response. This is similar to an analogy which Professor George Ekama (Dept of Civil Engineering, UCT), a leading scientist in wastewater treatment and process design, refers to where engineers, if, for example, are confronted with modelling the dynamics of carbon dioxide utilisation ofa forest, would recognise the accumulative system response and not give cognisance to each individual tree's contribution. It is true that if one had to consider every microbial species present in a highly organised community such as activated sludge, process models, designed to make quantitative and qualitative predictions as to the expected effluent quality from a particular design, would become increasingly complex and superfluous. It is evident from the countless accomplishments that engineers have succeeded, to a certain degree, in modelling wastewater treatment systems. One only has to consider the tremendous success of biological P (bio-P) removal and nitrification/denitrification processes at full-scale. However, there are limitations to this empirical approach and EBPR processes occasionally deteriorate in phosphate removal efficiency. In order to further optimise biological processes, whether they be organics oxidation, bio-P removal, nitrification or denitrification, biological community analyses will have to play a more significant role in design. The better microbial community structure and function is understood, the better the control and management of the system. With the advent of improved microbial identification and enumeration (to a certain extent) techniques (in situ), it was considered significant to investigate the mechanism ofbio-P removal and to elucidate which bacteria are actively responsible for this process. To this end, experimental work was conducted in two phases: \xAE laboratory, where samples of mixed liquor were obtained from a full-scale wastewater treatment facility exhibiting biological nutrient removal (BNR) characteristics and @ pilot plant, where an enhanced culture ofpolyphosphate accumulating organisms (PAO's) was developed and probed using molecular identification and enumeration techniques (as well as a cultivation-dependent approach). During phase \xAE of experimentat
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Matos, Leonor Rato Azevedo de. "Optimization of phosphate accumulating bacterial strains for phosphorus obtainment in residual water." Master's thesis, 2021. http://hdl.handle.net/10316/96109.
Повний текст джерелаO fósforo é um elemento essencial, que está presente em todos os seres vivos. Paradoxalmente, este elemento é ao mesmo tempo responsável por um tipo de poluição aquática devido a causas antropogénicas, e está em risco de escassez no futuro. As lamas ativadas, usadas em estações de tratamento de águas residuais, são ricas em fósforo e alguns países Europeus têm vindo a implementar legislações que fazem com que seja obrigatória a recuperação de fósforo nas estações de tratamento de águas.O objetivo deste trabalho é estudar a eficácia de bioaumentação de lamas ativadas numa estação de tratamento de águas residuais de escala laboratorial, para o melhoramento do processo de remoção de fósforo utilizando estirpes de bactérias nativas ou geneticamente modificadas, capazes de remover fósforo de águas residuais, nomeadamente as estipes Acinetobacter johnsonii 5bvlmeb2 e Escherichia coli BL21_pET30a_ppk1, respetivamente.Nas experiências de bioaumentação, realizada numa estação de tratamento de águas a escala laboratorial, a quantificação diária do fósforo presente no efluente, durante 5 dias, mostrou que a concentração média de fósforo na água, comparada com o controlo, foi reduzida em mais de metade quando se bioaumentou com E. coli BL21_pET30a_ppk1 ao mesmo tempo que a acumulação de polifosfato nas células aumentou substancialmente. Estes resultados indicam que a bioaumentação de lamas ativadas com esta estirpe modificada poderá potencialmente melhorar o desempenho da obtenção biológica de fósforo a partir de águas residuais no futuro e, por isso, mais estudos deverão ser realizados com a estirpe.
Phosphorus is an essential element that is found in every living entity. Paradoxically, not only is it responsible for aquatic eutrophication, due to anthropogenic causes, but is also at risk of shortage in the future. The activated sludge, produced, during wastewater treatment, is rich in this element and European countries have been implementing legislations making nutrient recovery, i.e. phosphorus, from wastewater facilities mandatory.The focus of this thesis is on studying native and genetically modified bacterial strains, such as Acinetobacter johnsonii 5bvlmeb2 and Escherichia coli BL21_pET30a_ppk1, respectively, which were show to be capable of removing phosphorus from wastewater. These will be used to bioaugment activated sludge in a laboratory-scale wastewater treatment plant. for the purpose of understanding if the bioaugmentation is efficient or not in improving the phosphorus removal process.Daily phosphorus quantification of the effluent water from the 5-day bioaugmentation experiments, performed in a laboratory-scale wastewater treatment, showed that the average residual phosphorus concentration was reduced by more than half in comparison to the control when using E. coli BL21_pET30a_ppk1. It was also shown that the polyphosphate uptake increased substantially. These results indicate that activated sludge bioaugmentation using this modified strain could potentially improve biological phosphorus removal in the future and, for that, more studies should be conducted with more depth.
Outro - Bolsa do Programa Erasmus+, durante 3 meses, financiada pela Comissão Europeia
Zhang, Miaomin. "Controlling salmonella accumulation inside solid tumors via bacterial chemotaxis engineering and combined treatment with lipid A." 2012. https://scholarworks.umass.edu/dissertations/AAI3546051.
Повний текст джерелаYeh, Ying-Chih, and 葉穎緻. "A study of polyphosphate-accumulating ability for purple non-sulfur bacteria under different cultivation conditions." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/52967886125684054010.
Повний текст джерелаGagnon, Hubert. "The isoflavonoids of Lupinus albus, their constitutive and environmentally induced accumulation and secretion, and their effect on bacterial growth." Thesis, 1993. http://spectrum.library.concordia.ca/5187/1/MM90835.pdf.
Повний текст джерелаGlöß, Stefanie [Verfasser]. "Detektion und Charakterisierung Polyphosphatspeichernder Bakterien in Gewässersedimenten = Detection and characterization of polyphosphate accumulating bacteria in lake sediments / von Stefanie Glöß." 2010. http://d-nb.info/1012200728/34.
Повний текст джерела姚慧怡. "The Effect and Biochemical Characteristics of Different P/C Feeding Ratio on Culturing Polyphosphate Accumulating Bacteria by Sequential Batch Reactor." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/67955300882861644152.
Повний текст джерела國立臺灣大學
環境工程與科學系
86
The object of this research is to investigate how the different C/NH4-N/P(wt/wt/wt) feeding ratios influence the biochemical mechanisms of denitrification and phosphorous removal of the activated sludge in an anaerobic-aerobic alternated reactor. Experimental results indicated that when the feeding ratio is 500/50/10, the polyphosphorus-accumulating bacteria (PAB) become the dominant bacteria in the SBR bioreactor and total-P removal efficiency reaches to 100%. Howerver, while changing the feeding ratio to 500/50/25 and to 500/50/50, the relative increase of P source to NH4-N source results in other bacteria instead of PAB to be the dominant bacteria. By analyzing the quantity of PHB and glycogen contained in the cell of the PAB, we verified that: the decreasing trend of glycogen during the anaerobic stage (ORP≦-200mv) can illustrate that the glycolysis provides the reducing equivalent NADH2 or NAD(P)H to form PHB, however, during the initial anaerobic stage (while the ORP is still ≧-200mv which is due to the influence of aerobic state at the last batch), acetate will form the accumulation of glucose by Glyoxylate cycle, and the Glyoxylate cycle also provides the reducing equivalent to form the PHB. Also by STS modified method, this research discovered that the control of low-molecular-weight polyphosphate(LWP) is rather relative to the mechanism of phosphorous-release during anaerobic stage and the mechanism of phosphorous-uptake during aerobic stage.
Wu, Chie-Fan, and 吳之凡. "The effect of silver nanopacticles to against four different bacterias, bacterias in live feeds and black seabream (Acanthopagrus schlegeli) fertilized eggs, and its effects on the growth, survival rate and the accumulation of grouper (Epinephelus coioides)." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/50656913137333231164.
Повний текст джерела國立臺灣海洋大學
水產養殖學系
100
This study evaluated the efficacies of nanosilver solution (2000 ppm) and nanosilver non-woven fabric applied in aquaculture. The MIC value of nanosilver against Vibrio alginolyticus was 8 ppm; the MBC value was 16 ppm. Nanosilver of 2000 ppm could produce bacteriostatic circles against Vibrio alginolyticus, Vibrio parahaemolyticus, Aeromonas hydrophila and Edwardsiella tarda growth in TSA, with diameters of 14.0 ± 2.0, 14.0 ± 1.5, 7.5 ± 2.5 and 14.5 ± 2.0 mm, respectively. When V. alginolyticus or V. parahaemolyticus reached a bacterial count of 103 CFU/mL in seawater, treatment with 8 ppb nanosilver for 2 hours or 1/2 hour had a complete bacteriostatic effect; when the bacterial count increased to 105 CFU/mL, treatment time with the same concentration increased to 4 and 1 hour. When A. hydrophila or E. tarda reached a bacterial count of 103 CFU/mL in freshwater, treatment with 1 ppb nanosilver for 1/2 hour or 2 hours had a bacteriostatic effect; when the bacterial count increased to 105 CFU/mL, treatment with 2 ppb for 1/2 hour was effective. In the experiment to find the bacteroistatic effect of nanosilver in different salinities of seawater, 15 and 25 ppt seawater which contained 103 CFU/mL V. alginolyticus were treated with 8 ppb nanosilver, and the bacteriostatic effects could last for 2 days; when the salinity was increased to 35 ppt, the effect could only last for 1 day. When the nanosilver concentration was increased to 16 ppb, the effect could last for 4 days in 35 and 25 ppt seawater, and for 5 days in 15 ppt seawater. This experiment also confirmed that nanosilver, less than 16 ppb, would not affect the ammonia-nitrogen, nitrite, dissolved oxygen, pH or redox potential in aquaculture water. In the disinfectant experiment on live feeds, treatment of 16 ppb nanosilver on Brachionus plicatilis for 15 minutes could maintain their vitality and has a good bacteriostatic effect; however, nanosilver was unsuitable to be used for disinfection of Isochrysis galbana. Feeding diets supplemented with 800 ppb nanosilver to Epinephelus coioides for 8 weeks would not affect their growth or survival; nanosilver would not remain in the muscle tissues, but would remain in the liver, intestines, brain, and head kidney. Also, treatment with 25 ppb nanosilver on Acanthopagrus sivicolus fertilized eggs for 10 minutes could result in bacteriostasis, and their hatchability would not be affected. 15 grams of nanosilver non-woven fabric was used as a filter material to treat seawater contained 103 CFU/mL V. alginolyticus, at a water flow rate of 5 ± 0.5 mL/sec. After one filtration process, 50% of the bacteria could be diminished; after four processes, 75% could be diminished. This study assessed that nanosilver and nanosilver non-woven fabric were usable in aquaculture as a bacteriostatic supplement and as a filter material.