Rozprawy doktorskie na temat „Propionibacterium”
Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Propionibacterium.
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Propionibacterium”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Perry, Alexandra L. "Characterisation of propionibacterium acnes". Thesis, Aston University, 2004. http://publications.aston.ac.uk/11015/.
Pełny tekst źródłaStreszczenie:
This thesis has sought to investigate the phenotypic, genetic and antigenic properties of P. acnes strains isolated from sciatica patients undergoing microdiscectomy, normal skin, blood cultures, prosthetic hips and acne lesions. Isolates’ phenotype was examined by determining their biotype by analytical profile index, antimicrobial susceptibility, virulence factor expression and serotype. A molecular typing method for P. acnes was developed using random amplification of polymorphic DNA (RAPD). Patent serum was used to screen P. acnes strains for antigens expressed in vivo and the chemical composition determined. The serodiagnostic potential and inflammatory properties of identified antigens were assessed. The optimised and reproducible RAPD protocol classified strains into three major clusters and was found to distinguish between the serotypes I and II for a large number of clinical isolates. Molecular typing by RAPD also enabled the identification of a genotype that did not react with the type I or II monoclonal antibodies and these strains may therefore constitute a previously undiscovered subspecies of P. acnes with a genetic background different from the type I and II serotypes. A major cell-associated antigen produced by all strains as identified and characterised. A serological assay based on the antigen was used to measure IgG and IgM levels in serum from patients with acne, sciatica and controls. No difference in levels of antibodies was detected. Inflammatory properties of the antigen were measured by exposing murine macrophage-like cells and measuring the release of nitric oxide and tumour necrosis factor-alpha (TNF-a). Only TNF-a was elicited in response to the antigen. The phenotypic, genotypic and antigenic properties of this organism may provide a basis for future studies on P. acnes virulence and provide an insight into its mechanisms of pathogenesis.
2
Glenn, J. V. "Propionibacterium acnes and medical device infection". Thesis, Queen's University Belfast, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273034.
Pełny tekst źródła
3
Valanne, M. S. "The pathogenic potential of Propionibacterium acnes". Thesis, Queen's University Belfast, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273147.
Pełny tekst źródła
4
Fougnot, Sébastien Lozniewski Alain. "Etude de l'activité des antibiotiques sur propionibacterium acnes impliqué dans les infections neuro-méningées". [S.l] : [s.n], 2003. http://www.scd.uhp-nancy.fr/docnum/SCDMED_T_2003_FOUGNOT_SEBASTIEN.pdf.
Pełny tekst źródła
5
Lan, Annaïg. "Survie et potentialités probiotiques de Propionibacterium freudenreichii". Rennes 1, 2006. http://www.theses.fr/2006REN1S125.
Pełny tekst źródłaStreszczenie:
Afin d’étudier les potentialités probiotiques de P. Freudenreichii, une bactérie propionique laitière principalement étudiée pour ses propriétés technologiques en industrie fromagère, plusieurs souches ont été sélectionnées par criblages in vitro puis in vivo pour tester leur survie et leurs activités métaboliques dans le tractus digestif. Une des souches, présentant des aptitudes probiotiques in vitro et in vivo, a été administrée à des rats à microbiote humain afin de tester son influence sur la carcinogenèse colique à court et à moyen termes. Cette souche s’est révélée être protectrice dans les stades précoces de carcinogenèse en augmentant significativement l’apoptose des cellules épithéliales coliques mais est sans effet sur la réduction du nombre de lésions prénéoplasiques coliques. Par ailleurs, les scénarii létaux induits par les métabolites des propionibactéries in vitro ont été identifiés et précisés en tenant compte du gradient de pH, variable physiologique intestinale.
6
Fachin, Luciano. "Contagem de Bifidobacterium animalis Bb 12 e efeito da adição de Propionibacterium freudenreichii PS-1 e do tratamento termico do leite sobre o desenvolvimento de Bifidobacterium animalis Bb 12 em iogurte". [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255805.
Pełny tekst źródłaStreszczenie:
Orientadores: Walkiria Hanada Viotto, Mieko KimuraTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-04T02:47:09Z (GMT). No. of bitstreams: 1 Fachin_Luciano_D.pdf: 623874 bytes, checksum: 39038138708fcb9d94eb3e5320272cbb (MD5) Previous issue date: 2005
Resumo: A produção de iogurtes com Bifidobacterium spp. tem crescido muito nas últimas décadas visando a produção de alimentos funcionais. Contudo, para que o produto possa apresentar tais propriedades, tem sido alegado que o número mínimo de células viáveis de Bifidobacterium spp. presentes no momento do consumo deva ser de 106 UFC/g de produto. Entretanto, vários estudos têm mostrado produtos comerciais com contagens menores do que as recomendadas, durante a estocagem do iogurte. Esse fato é reflexo tanto da dificuldade de incorporação destes microrganismos ao iogurte, devido às condições de processo que não são favoráveis ao desenvolvimento da bifidobactéria, bem como pela dificuldade de enumeração destes microrganismos na presença das culturas do iogurte. Este trabalho avaliou o uso dos meios M-MRS, MRS-NNLP, MRS-LP, RCPB pH5 e RCPB pH5 enriquecido com extrato de fígado, visando a contagem seletiva ou diferencial de Bifidobacterium animalis Bb 12 na presença das culturas do iogurte e estudou o efeito do tratamento térmico do leite, visando o aumento do teor de lactulose e, da adição de Propionibacterium freudenreichii PS-1, sobre o desenvolvimento e manutenção do número de células viáveis de B. animalis Bb 12 durante a fermentação e estocagem do iogurte. Dos meios estudados, o meio RCPB pH5, enriquecido com 150mL/L de extrato de fígado, foi o mais indicado para a contagem de B. animalis Bb 12 em iogurte por ter apresentado uma excelente diferenciação deste microrganismo, após a estocagem refrigerada do iogurte. O tratamento térmico do leite de 142°C/15 segundos não afetou o desenvolvimento de B. animalis Bb 12 durante a fermentação do iogurte e também não influenciou a sua resistência à estocagem refrigerada. Entretanto, o tratamento térmico alterou significativamente a textura, diminuindo consideravelmente a dureza, gomosidade e adesividade do iogurte, resultando em um produto com menor separação de soro. A adição de P. freudenreichii PS-1 aumentou em aproximadamente duas vezes o número de células de B. animalis Bb 12 ao final da fermentação e melhorou a resistência da bifidobactéria à estocagem refrigerada. A presença da propionibactéria também alterou significativamente a textura final do iogurte, aumentando consideravelmente a gomosidade e adesividade do produto final, bem como resultou em um iogurte com menor separação de soro durante a estocagem refrigerada
Abstract: Bifidobacterium spp. has been used to produce probiotic yoghurts due to its therapeutic properties. However, it has been claimed that the number of bifidobactéria in yoghurt at the time of consuming must be 106 CFU /g of product to perform their therapeutic functions. Many studies found a low recovery of bifidobactéria from commercial products during shelf life. The low viability of bifidobactéria can be attributed to the process conditions of yoghurt, which is not favorable to the growth of bifidobactéria, and to the difficulty for enumeration of bifidobactéria in the presence of yoghurt bacteria. The objectives of this work were to evaluate the following media: M-MRS, MRS-NNLP, MRS-LP, RCPB pH5 and fortified RCPB pH5 to enumerate B. animalis Bb 12 in yoghurt, and to evaluate the heat treatment of milk (142°C/15 seconds) and the addition of P. freudenreichii PS-1 on the growth of B. animalis Bb 12 during yoghurt fermentation and during shelf life. RCPB pH5 fortified with 150 mL/L of liver extract was the best media due to its excellent differentiation during refrigerated storage of yoghurt. The heat treatment of milk (142°C/15 seconds) did not have effect on the growth of bifidobactéria during fermentation and it also did not improve the bifidus viability during storage. Heat treatment, however, had a strong effect on yoghurt texture, decreasing the sineresis and some parameters of TPA (hardness, gumminess and adhesiveness). The addition of P. freudenreichii PS-1 increased two fold the bifidobactéria growing during yoghurt fermentation and it also increased the viability of bifidobactéria during yoghurt shelf life. The addition of P. freudenreichii PS-1 also decreased the sineresis and increased TPA parameters of hardness, gumminess and adhesiveness. Addition of P. freudenreichii PS-1 to the yoghurt seems to be a good growth promoter for B. animalis Bb 12
Doutorado
Tecnologia de Alimentos
Doutor em Tecnologia de Alimentos
7
Curiche, Natalia. "Visualization of Propionibacterium acnes in Patients Diagnosed with Acne Vulgaris. - Propionibacterium acnes Detected with Immunofluorescence and Fluorescence in situ Hybridization". Thesis, Umeå universitet, Biomedicinsk laboratorievetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-58623.
Pełny tekst źródła
8
Van, der Merwe Iansha (Iansha Rosalia) 1975. "Characterization of thoeniicin 447 produced by Propionibacterium thoenii". Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52729.
Pełny tekst źródłaStreszczenie:
Thesis (MSc)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: Antimicrobial peptides continue to be one of the most important classes of food additives. The food industry is especially interested in the application of naturally occuring and biologically derived preservatives. Among the metabolites of industrial importance produced by propionibacteria are peptides called bacteriocins. Bacteriocins are ribosomally synthesized peptides with antagonistic activity against closely related microorganisms. Many microorganisms associated with food produce bacteriocins, which have stimulated interest in the use of these peptides as natural food preservatives. Numerous bacteriocins are produced by lactic acid bacteria, but only a few have been reported for propionibacteria. Since propionic acid bacteria have GRAS (generally regarded as safe) status, their metabolic compounds should be safe for human consumption. Propionibacterium thoenii 447, isolated from Emmentaler cheese, produces a bacteriocin-like peptide, named thoeniicin 447, with a narrow spectrum of activity. The peptide displays a bactericidal mode of action against Lactobacillus delbrueckii subsp. bulgaricus and a bacteriostatic action against Propionibacterium acnes. Optimal bacteriocin production was detected during the early stationary growth phase. The peptide is resistant to heat treatments of 60°C and 80°C for 15 and 30 min and to 100°C for 15 min, but loses 80% of its activity after autoclaving (10 min at 121°C). Thoeniicin 447 remains active after incubation in buffers with pH values ranging from 1-10. The peptide is inactivated by pepsin, pronase, a-chymotrypsin, trypsin and Proteinase K. Thoeniicin 447 was partially purified by ammonium sulfate precipitation, followed by SP-Sepharose cation exchange chromatography. The estimated size of thoeniicin 447, according to tricine-SDSPAGE, is approximately 6 kDa. Based on DNA sequencing, the mature peptide is 7130 Da in size and homologous to propionicin Tl produced by P. thoenii strain 419. Thoeniicin 447 is a relatively small, cationic and heat-stable peptide and can therefor be classified as a member of class II bacteriocins. These features are very similar to those of bacteriocins produced by lactic acid bacteria. However, no unique classification system has been proposed for bacteriocins of propionibacteria. As a member of the genus Propionibacterium, P. thoenii 447 is generally regarded as safe. This, together with the narrow spectrum of activity, particularly the action against P. acnes, heat tolerance of thoeniicin 447 and its activity over a wide pH range renders the peptide suitable for possible pharmaceutical applications.
AFRIKAANSE OPSOMMING: Antimikrobiese middels sal deurgaans beskou word as een van die belangrikste klasse van voedsel bymiddels. Die voedselindustrie is veral geïnteresseerd in die toepassing van preserveermiddels van 'n meer natuurlike en biologiese oorsprong. Onder die metaboliese produkte van industriële belang wat deur propionibakterieë geproduseer word is antimikrobiese peptiede (bakteriosiene). Bakteriosiene is ribosomaal-gesintetiseerde peptiede met 'n antagonistiese aktiwiteit teenoor naverwante bakterieë. Verskeie bakteriosiene word deur melksuurbakterieë geproduseer, terwyl slegs enkele vir propionibakterieë beskryf is. Baie van hierdie propionibakterieë word in die algemeen as veilig beskou en het GRAS status. Die metaboliete wat hulle produseer behoort dus veilig vir menslike gebruik te wees. Propionibacterium thoenii 447 is uit Emmentaler kaas geisoleer en produseer 'n bakteriosien-agtige peptied, naamlik thoeniicin 447 met 'n beperkte spektrum van aktiwiteit. Die peptied het 'n bakteriosidiese werking teenoor Lactobacillus delbrueckii subsp. bulgaricus en 'n bakteriostatiese werking teenoor Propionibacterium acnes. Optimum bakteriosien produksie is verkry tydens die vroeë stationêre groeifase. Die peptied is bestand teen hittebehandelings van 60°C en 80°C vir 15 en 30 min, asook 100°C vir 15 min, maar verloor 80% van sy aktiwiteit na outoklavering (lOmin by 121°C). Die peptied blyaktief na inkubasie in buffers van pH 1-10. Die peptied word deur pepsien, pronase, uchymotripsien, tripsien en Proteinase K geïnaktiveer. Thoeniicin 447 is met behulp van ammoniumsulfaat-presipitasie, gevolg deur SPSepharose katioon-uitruilchromatografie gedeeltelik gesuiwer. Skeiding op "n trisien-SDS poliakrielarnied-jel het 'n aktiewe band van ongeveer 6 kDa getoon. Volgens die DNA volgorde bepaling is thoeniicin 447, 7130 Da in grootte en homoloog aan Propionicin Tl, geisoleer vanaf P. thoenii stam 419. Thoeniicin 447 is 'n relatiewe klein, kationiese en hitte-bestande peptied en kan op grond hiervan as 'n lid van die klas II bakteriosiene geklassifiseer word. Hierdie eienskappe is soortgelyk aan die eienskappe van bakteriosiene geproduseer deur melksuurbakterieë. Tot op hede is geen klassifikasiesisteem vir die bakteriosiene van propionibakterieë voorgestel nie. As 'n lid van die genus Propionibacterium, word P. thoenii 447 in die algemeen as veilig beskou. Dit, tesame met die nou spektrum van aktiwiteit, veral teenoor P. acnes, die hittetoleransie van thoeniicin 447, asook die aktiwiteit oor 'n wye pH-grens, maak die peptied geskik vir moontlike farmaseutiese toepassings.
9
Grassi, Maria Carolina de Barros 1984. "Estudo genético e metabólico da bactéria Propionibacterium acidipropionici". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316784.
Pełny tekst źródłaStreszczenie:
Orientadores: Gonçalo Amarante Guimarães Pereira, Johana Rincones PerezTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-22T01:57:47Z (GMT). No. of bitstreams: 1 Grassi_MariaCarolinadeBarros_D.pdf: 11791511 bytes, checksum: e41c1f0116c9c3dcfd0795e255f117a9 (MD5) Previous issue date: 2012
Resumo: O resumo poderá ser visualizado no texto completo da tese digital
Abstract: The abstract is available with the full electronic document
Doutorado
Genetica de Microorganismos
Doutor em Genetica e Biologia Molecular
10
Vieira, Machado Eduardo Souza. "Culture de propionibacterium freudenreichii et production d'arôme emmental". Compiègne, 1994. http://www.theses.fr/1994COMP734S.
Pełny tekst źródłaStreszczenie:
La biomasse de propionibacterium freudenreichii a été préparée en vue de la production d'arome emmental. Dans une première partie nous avons étudié l'effet de l'aération, de l'agent de neutralisation et de l'addition d'extrait de levure sur la croissance des bactéries propioniques cultivées sur lactoserum proteolyse a 32c et ph 6,8. Les résultats obtenus démontrent que la souche répond favorablement à une faible aération (1,0 vvm/200 rpm), et la vitalité mesurée en termes de ufc/ml passe de 0,2 a 1,2. 10#1#0 ufc/ml. Des conditions d'aération plus énergiques sont nuisibles pour les cellules. L'utilisation de nh#4oh a la place de naoh a permis d'augmenter de 11,4% la matière sèche de la culture et la vitalité en termes d'ufc/ml. L'hydroxyde de calcium n'a pas d'effet important sur le dénombrement maximal mais les cultures produites avec son utilisation sont plus stables. Une fois déterminées les conditions optimales, des cultures ont été conduites pour l'obtention de la biomasse pour la production de l'arome emmental sur caille granulaire. L'addition d'extrait de levure s'est montrée favorable à la production de biomasse et à la vitalité, mais réduit le rapport acide propionique/acide acétique des cultures. Cinq types de caille ont été testés, tout en variant les cultures d'inoculation: bactéries propioniques pures, et additionnées de l. Helveticus, s. Thermophilus ou mélangé des deux souches à 0,1% ou 1,0% de chaque souche lactique. Le meilleur caille a été obtenu après l'addition des souches lactiques a 0,1%. Ce caille soumis a un panel de dégustation a été considéré comme type et de force 5.
11
Lin, Yu-fei. "Genome-wide analysis of Propionibacterium acnes gene regulation". Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/15231/.
Pełny tekst źródłaStreszczenie:
Sequencing of the genome of Propionibacterium acnes produced a catalogue of genes many of which enable this organism to colonise sites in human skin and survive a range of environmental challenges. However as yet, there is little understanding of the relationships and interactions between genes that give rise to an organism, which has major impact on human health and wellbeing as an opportunistic pathogen that causes infections beyond the skin. To provide a platform for better understanding gene regulation in P. acnes, this thesis shows using microarrays, reproducible genetic responses to external changes relevant to the skin environment in P. acnes can be studied using batch cultures. It then goes on to describe the generation of nucleotide-resolution maps of the primary and secondary transcriptome. The maps were produced by combining differential and global RNA sequencing approaches. Sites of transcriptional initiation, stable RNA processing and mRNA cleavage as well as riboswitches, small non-coding RNAs, vegetative promoters, and previously undetected genes were identified across the genome. In addition, evidence was obtained for the widespread use of leaderless mRNAs, which may be translated by specialised ribosomes. Preliminary evidence for the existence of the latter, in the form of particular ribosomal RNA processing, was obtained. The study also provided statistically robust evidence for pervasive transcription that is associated with both the sense and antisense strands of coding regions. Continuing annotation of the primary and secondary transcriptomes of pathogens will assist comparative and functional genomics approaches and may also aid the modelling of the disease process and therapeutic development.
12
Pruitt, Corunda T. "Effects of compatible solutes on cold tolerance of propionibacterium freudenreichii and the significance of propionibacterium cold tolerance in Swiss cheese manufacturing". Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1123184280.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xiv, 107 p.; also includes graphics. Includes bibliographical references (p. 90-97). Available online via OhioLINK's ETD Center
13
Dahlberg, Ida. "Förekomsten av Propionibacterium acnes är låg hos patienter med Rosacea : En studie av sambandet mellan Propionibacterium acnes och Rosacea med immunofluorescens". Thesis, Umeå universitet, Biomedicinsk laboratorievetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-58624.
Pełny tekst źródła
14
Guérin, Philippe. "Osteomyelite multifocale a propionibacterium acnes : a propos d'un cas". Clermont-Ferrand 1, 1993. http://www.theses.fr/1993CLF1M031.
Pełny tekst źródła
15
Mak, Tim Nam [Verfasser]. "Host modulating properties of Propionibacterium acnes / Tim Nam Mak". Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1033306703/34.
Pełny tekst źródła
16
Joubert, Hannarine. "Optimisation of propionibacterial ECP production and the influence of propionibacteria on the UASB granulation process". Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51866.
Pełny tekst źródłaStreszczenie:
Thesis (MSc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: The "classical" propionibacteria are used in a variety of natural dairy fermentations where they produce natural preservatives (propionic and acetic acids and bacteriocins) and large amounts of vitamin B12. The extracellular polysaccharide (ECP) producing ability of these bacteria also make them of special interest to the food and waste water management industries as the ECP has been illustrated to playa role in the initial granule formation in upflow anaerobic bioreactor systems. There is little known on the ECP production by propionibacteria and in this study different environmental conditions that influence ECP production were studied. Nineteen different Propionibacterium strains were examined in terms of ECP production and Propionibacterium strain 278 was identified as the best ECP producer. Further studies were only done on this strain because of its high ECP production and because it was originally isolated from an anaerobic digester. The influence of temperature, pH and sucrose concentration was determined through the measurement of ECP production and medium viscosity. It was found that more ECP was produced at temperatures lower than the optimum for growth with the optimum being between 22° and 25°C. Lower initial pH conditions of the growth medium (below pH 7.0) were found to inhibit ECP production and the influence when the initial pH values were between 7.0 and 8.5, was not significant. A higher carbon: nitrogen ratio, when 8% sucrose was added, was also found to enhance the ECP production. The upflow anaerobic sludge bed (UASB) bioreactor process depends on the upward movement of soluble matter through a blanket of active methanogenic granular sludge. The long start-up times as a result of the slow granulation process, as well as the need for a speedy replacement of granules once they have been washed out of the system, are limitations that restrict the general application of this excellent waste water treatment technology. Full exploitation of this biomass immobilisation technique can thus not be realised until the granule formation conditions are defined and optimised. The precise nature of the mechanisms involved in the formation of granules and the reason for their stability, is still not fully understood. It was hypothised by Britz et al. in 1999 that, through the implementation of environmental 'stress' conditions, a shift in the population dynamics of the anaerobic community can be obtained. This results in a concurrent increase in ECP formation that appears to enhance aggregate formation. In the second study it was found that, when 'stress' conditions were applied to already formed granules, the Gram-positive lactate-utilising acidogenic population gained an advantage and more propionic acid producing bacteria were present. The propionic and acetic acid concentrations were also found to increase, and concurrently, a decrease in the growth medium pH occurred. This confirms part of the granulation hypothesis that, when granules are 'stressed', the acidogenic population dynamics change and the lactate-utilising population responds to the gradual decrease in pH and the more acid-tolerant propionic acid producing bacteria gain a competitive advantage resulting in the increase in the propionic acid concentration. When propionibacteria were added to raw sludge during the granule production process, the granules were found to be more active than when nopropionibacteria had been added. This was probably due to the ECP formation by the propionibacteria that enhances the aggregation of the granules. Enhanced granulation was thus found in the batch systems with the fatty acids formed in correlation with the model for granulation. A good correlation was evident between the hypothesis and the experimental data and the hypothesis was partially verified in this study.
AFRIKAANSE OPSOMMING: Die "klassieke" propionibakterieë word in 'n verskeidenheid van natuurlike suiwel fermantasies gebruik waarin hulle verantwoordelik in vir die produksie van natuurlike voedsel preserveermiddels (propioonsuur, asynsuur en bakteriosiene) en groot hoeveelhede vitamiene B12. Die Ekstra Sellulêre Pollisakkaried (ESP) produserende eienskap van hierdie groep bakterieë maak hulle ook van belang in die voedsel en afvoerwater beheer industrieë, aangesien gevind is dat ESP 'n rol speel in die aanvanklike granule formasie in anaerobiese bioreaktor sisteme. Daar is nog baie min bekend oor die ESP produksie van propionibakterieë en in hierdie studie is verskeie omgewings faktore wat die ESP produksie beïnvloed, bestudeer. Negentien verskillende Propionibakterium stamme was bestudeer in terme van ESP produksie en Propionibakterium stam 278 was geïdentifiseer as die stam wat die meeste ESP produseer. Verdere studies was op hierdie stam gedoen na aanleiding van sy hoë ESP produksie en omdat dit oorspronklik uit 'n anaerobiese verteerder geisoleer is. Die invloed van termperatuur, pH en sukrose konsentrasie was bepaal deur die meting van die ESP produksie en die medium viskositeit. Dit was gevind dat meer ESP geproduseer was by temperature laer as die optimum vir groei, met die optimum temperatuur tussen 22° en 25°C. Dit is ook gevind dat laer aanvangs groei-medium pH (laer as pH 7.0), ESP produksie inhibeer. Die invloed van die aanvangs groei-medium pH tussen 7.0 en 8.5 was egter nie betekenisvol nie. Dit is ook gevind dat 'n hoër koolstof tot stikstof verhouding, verkry deur die byvoeging van 8% sukrose, die ESP produksie verhoog. Die "upflow anaerobic sludge blanket" (UASB) proses vind plaas as gevolg van die opwaarste beweging van opgeloste organiese materiaal deur 'n granule bed van aktiewe metanogeniese granulêre slyk. Die lang 'start-up' tye as gevolg van die stadige granulasie proses, en die nodigheid om 'n vinnige verplasing van granules te hê nadat dit uit die sisteem gewas is, is beperkings wat die algemene toepassing van hierdie fantastiese afvoerwater tegnologie, strem. Volle implementering van hierdie biomassa immobilisereings tegniek kan dus nie plaasvind voordat die granule formasie gedefinieer en geoptimiseer is nie. Die presiese eienskappe van die meganismes betrokke en die formasie van die granules en die rede vir hul stabiliteit word egter nog nie ten volle verstaan nie. Volgens 'n hipotese deur Britz et al. (1999), vind 'n verskuiwing in die populasie dinamika van die anaerobiese gemeenskap plaas tydens die implementasie van omgewings 'stress' toestande. Die resultaat is 'n verhoging in ESP produksie en 'n gevolglike verbetering in die granulasie proses. In die tweede studie was dit gevind dat, wanneer 'stress' toestande op die reeds gevormde granulasie toegepas word, die Gram-positiewe laktaat-benuttende asetogeniese populasie voordeel geniet en meer propioonsuur produserende bakterieë was teenwoordig. Die propioonsuur en asynsuur konsentrasies het ook verhoog en met 'n gevolglike daling in die groei-medium se pH. Dit bevestig 'n gedeelte van die hipotese dat, wanneer die granules onder 'stress' geplaas word, die asetogeniese populasie dinamika verander en die laktaat-benuttende populasie reageer tot die gedeeltelike afname in pH. Die meer suur-tolerante propioonsuur produserende bakterieë verkry 'n kompeterende voordeel en gevolglik is daar 'n verhoging in propioonsuur konsentrasie. Propionibakterieë was gevoeg by die onbehandelde slyk gedurende die granule produksie proses, en daar is gevind dat meer aktiewe granules gevorm word as andersins. Dit is moontlik as gevolg van die die ESP produksie van propionibakterieë wat die granulasie versnel het. Verbeterde granulasie was dus verkry in die sisteme waar propionibakterieë bygevoeg is. Vetsuur analises het gedui dat die gevormde vetsure ook in korrelasie was met die model van granulasie. Goeie korrelasie was dus verkry tussen die hipotese en die eksperimentele data en die hipotese is gedeeltelik bewys in hierdie studie.
17
Whale, Gary Anthony. "Purification and characterisation of the lipid macroamphiphiles of propionibacterium acnes". Thesis, Robert Gordon University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270026.
Pełny tekst źródła
18
Bassalo, Marcelo Colika 1989. "Estudo do metabolismo aeróbico da bactéria anaeróbica facultativa Propionibacterium acidipropionici". [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316761.
Pełny tekst źródłaStreszczenie:
Orientador: Gonçalo Amarante Guimarães PereiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-23T08:13:02Z (GMT). No. of bitstreams: 1 Bassalo_MarceloColika_M.pdf: 8530833 bytes, checksum: 675d7e6b45b1284552a7e3f9939d929a (MD5) Previous issue date: 2013
Resumo: A sociedade atual é fundamentalmente dependente do petróleo, recurso natural inserido na grande maioria dos setores da economia. Entretanto, fatores como a limitada disponibilidade deste recurso, sua instabilidade no mercado devido a problemas de natureza geopolítica e a emissão de dióxido de carbono ocasionada pela utilização deste combustível, acentuaram as iniciativas para substituir o petróleo por fontes alternativas e renováveis de matéria prima. A bactéria Propionibacterium acidipropionici surge como uma excelente candidata para a substituição de compostos petroquímicos, através da produção do ácido propiônico. No entanto, antes de transformar esta bactéria em uma plataforma industrial, é necessário aprofundar a compreensão do metabolismo deste microrganismo e desenvolver ferramentas de manipulação genética. No que diz respeito à compreensão do metabolismo, poucos estudos avaliaram o perfil aeróbico desta bactéria, considerada anaeróbica estrita até recentemente. No presente trabalho, foi identificada nesta bactéria a presença de todos os componentes de uma cadeia transportadora de elétrons. No entanto, a citocromo c oxidase identificada apresenta-se mutada e os testes realizados confirmaram a não funcionalidade deste complexo. A existência de uma oxidase alternativa, a citocromo bd oxidase, caracterizada pela alta afinidade ao oxigênio, surge então como uma hipótese promissora acerca da microaerofilia desta bactéria. O trabalho também avaliou o perfil fermentativo dessa bactéria em condições aeróbicas com diferentes fontes de carbono, o que ressaltou a enorme flexibilidade metabólica apresentada por P. acidipropionici, capaz de redirecionar o fluxo de carbono para diferentes produtos finais a depender da necessidade de manutenção do balanço redox. Este estudo também revelou uma propriedade bastante peculiar e industrialmente relevante do xarope de cana-de-açúcar. A fermentação aeróbica com este substrato, ao contrário de todas as outras fontes de carbono, apresentou um crescimento superior ao das condições anaeróbicas e, adicionalmente, exibiu um perfil fermentativo próximo ao observado em ausência de oxigênio. A identificação do composto presente no xarope de cana-de-açúcar, responsável por simular o metabolismo anaeróbico, poderia viabilizar a produção do ácido propiônico em dornas de fermentação aeróbicas, o que traria enormes benefícios para a produção economicamente viável do ácido propiônico e na implementação de P. acidipropionici como uma plataforma industrial
Abstract: The dependence of contemporary society on petroleum is axiomatic, and this natural resource could be found intrinsically embedded in the vast majority of economic sectors. Nonetheless, the limited availability of this natural resource, the instability in the stock market due to geopolitical problems, and also the carbon dioxide emissions associated with the use of fossil fuels have highlighted the need to search for renewable energy sources. The bacteria Propionibacterium acidipropionici arises as an excellent strategy for the substitution of petrochemical compounds, through the production of propionic acid. Before we could implement this bacterium as an industrial platform, however, it becomes necessary to enhance the knowledge regarding the metabolism of P. acidipropionici, and thus create a backbone for the development of genetic manipulation tools. Regarding the metabolism of this bacterium, there aren't comprehensive studies about its aerobic metabolism, thus being considered strict anaerobes until recently. In the present work, it was identified that P. acidipropionici has all required components for a functional electron transport chain. However, the cytochrome c oxidase of this bacterium has a frameshift mutation, and the functional studies proved that this complex is not operative. The presence of an alternative oxidase of high oxygen affinity, called cytochrome bd oxidase, is then suggested as a hypothesis to explain the microaerofilic habit of this bacterium. This work has also shed light into the fermentative profile showed by this bacterium under aerobic cultivation with different carbon sources, bringing attention to the highly flexible metabolism of P. acidipropionici. This bacterium has shown to be capable of completely changing its carbon flux to different end products, as a strategy to maintain the redox balance. In addition, this work has also unveiled an interesting and industrially-relevant property of the sugar cane syrup. It was demonstrated that the aerobic cultivation of P. acidipropionici with sugar cane syrup increased the culture growth, as well as it changed the fermentation end products in a way more similar to the anaerobic cultivation. It was hypothesized that this unusual property found in the sugar cane syrup was due to the presence of a mineral compound that could be used as a final electron acceptor by P. acidipropionici. The identification of this specific compound would allow the aerobic production of propionic acid in industrial conditions, and thus could be a major breakthrough to turn its industrial production into an economically viable process
Mestrado
Genetica de Microorganismos
Mestre em Genética e Biologia Molecular
19
Calabrese, Ana Paula Mazine. "Estudos da inativação de Propionibacterium acnes por fotodinamização de hipericina". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-04012013-161203/.
Pełny tekst źródłaStreszczenie:
Um dos maiores desafios na área médica dermatológica tem sido o tratamento da acne. Esta dermatose afeta 80 a 90% dos adolescentes. A busca por tratamentos alternativos tornou-se importante devido à resistência bacteriana de Propionibacterium acnes (P. acnes) aos antibióticos comumente utilizados contra este agente etiológico e pelos efeitos colaterais produzidos por estas drogas. Visando minimizar estes efeitos colaterais e proporcionar a eliminação de P. acnes, uma nova modalidade de tratamento vem sendo pesquisada, a terapia fotodinâmica (TFD). TFD já está bem estabelecida no combate a muitos tipos de câncer e tem se mostrado promissora na área estética. Os protocolos de TFD para tratar a acne tem como base a síntese endógena de hematoporfirina e compostos relacionados induzida por ácido 5-aminolevulínico (ALA), um tratamento com tempo de incubação grande, dolorido e usando a luz azul. O objetivo deste estudo foi de um modo geral avaliar a eficácia da inativação fotodinâmica sobre o microrganismo P. acnes utilizando como FS a hipericina e irradiado com um LED amarelo (590 nm). A inativação do microorganismo foi conseguida mesmo com uma concentração baixa de hipericina (menos de 1 \'mü\'g/mL) e foi caracterizada pelo curto tempo de bioacumulação estacionária (cerca de 2 min 30 s). A eficiência fotodinâmica de hipericina foi comprovada nos experimentos, e também pode-se observar que o uso do LED amarelo a partir de doses pequenas (4,55 ± 0,08 J \'CM POT.-2\') sendo capaz de reduzir 63% das células viáveis utilizando 10 \'mü\'g/mL de hipericina.One of the prominent challenges in medical dermatology has been the treatment of acne. The acne affects 80 to 90% of teenagers. The search for alternative treatment has become important due to bacterial resistance of P. acnes to usually applied antibiotics against this etiologic agent and the side effects produced by these drugs. In order to overcome these limitations to inactivated the P. acnes, the photodynamic based protocols has been studied. Already, well established named photodynamic therapy has been used against many cancers and the use of light has shown promise in the esthetic area, the photodynamic protocols has been used to treat acne based on endogenous synthesis of hematoporphyrin and related compounds induced by -aminolevulinic acid, a long term treatment and using the blue light. The objective of this study was to evaluate the effectiveness of photodynamic inactivation of the P. acnes using hypericin, irradiated by a yellow LED (590 nm). The microorganism inactivation was achieved even at low concentration of hypericin (less than 1 \'mü\'g/mL), and was characterized by the short time bioaccumulation stationary state (around 2.5 minutes). In order to guarantee the reproducibility typically the incubation time was 10 minutes. The photodynamic efficiency was evaluated to be 4.55 ± 0.08 J \'CM POT.-2\' able to reduce 63% of the viable cells using 10 \'mü\'g/mL of hypericin. These results allow concluding that the hypericin is an effective FS to inactivate P. acnes.
20
Davis, Nigel. "The structural genes for methylmalonyl-CoA metabolism in Propionibacterium shermanii". Thesis, University of Cambridge, 1986. https://www.repository.cam.ac.uk/handle/1810/270400.
Pełny tekst źródła
21
LEMEE, RIWANON. "Systeme autolytique de propionibacterium freudenreichii cnrz 725 bacterie propionique laitiere". Rennes 1, 1994. http://www.theses.fr/1994REN10198.
Pełny tekst źródłaStreszczenie:
Les bacteries propioniques laitieres et en particulier celles de l'espece propionibacterium freudenreichii, jouent un role majeur dans l'etape de l'affinage des fromages a pate pressee cuite, type emmental par leur intervention dans l'ouverture de la pate et certainement dans la proteolyse du caille. Or la proteolyse due en partie a des peptidases intracellulaires implique la liberation de ces enzymes dans la pate par eclatement des bacteries nommees autolyse. Lors de cette these nous avons determine des parametres inducteurs de l'autolyse par une approche biochimique et ultrastructurale. Ainsi la capacite a l'autolyse depend de la souche consideree, du stade de croissance cellulaire, de l'absence de nutriment carbone, des conditions physicochimiques du milieu environnant (ph, nature des sels, temperature,). Les enzymes responsables de l'autolyse cellulaire (nommees autolysines), au nombre de 8 chez p. Freudenreichii, ont ete partiellement caracterisees (pm, resistance thermique, glycosylation). Des etapes de purification de ces autolysines ont ete franchies. Les resultats obtenus contribueront a un choix moins empirique des levains propioniques utilises en fromagerie
22
Suwannakham, Supaporn. "Metabolic engineering for enhanced propionic acid fermentation by Propionibacterium acidipropionici". Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1111728310.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xix, 258 p.; also includes graphics (some col.) Includes bibliographical references (p. 199-212). Available online via OhioLINK's ETD Center
23
Duarte, Juliana Canto 1984. "Produção de ácidos orgânicos C-3 e C-4 através da fermentação de diferentes substratos por Propionibacterium acidipropionici". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266058.
Pełny tekst źródłaStreszczenie:
Orientador: Gustavo Paim ValençaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-26T07:00:33Z (GMT). No. of bitstreams: 1 Duarte_JulianaCanto_D.pdf: 4804028 bytes, checksum: 8a14cd7e6bdf26f6d7000302437af726 (MD5) Previous issue date: 2014
Resumo: Foram realizadas fermentações em batelada do sorbitol, sacarose, glicerol e glicose por Propionibacterium acidipropionici livre em biorreatores. As fermentações do sorbitol forneceram a maior concentração final de ácido propiônico (39,5±5,2 g L-1) e as fermentações da glicose forneceram a menor concentração final de ácido propiônico (23,9±2,1 g L-1). Apenas as fermentações do glicerol produziram n-propanol e sua concentração final foi de 1,7±0,1 g L-1, além disso, o ácido acético não foi produzido nas fermentações do glicerol. As fermentações da sacarose forneceram a maior concentração final de ácido acético (10,9±0,0 g L-1). O maior valor de produtividade do ácido propiônico foi obtido nas fermentações do sorbitol (0,60 g L-1 h-1). Fermentações do sorbitol e da sacarose em batelada utilizando células de P. acidipropionici livres e imobilizadas em montmorilonita K10 foram realizadas em três ciclos sequenciais com reciclo celular. As concentrações finais de ácido propiônico para as fermentações do sorbitol com células livres foram 39,5±5,2; 35,8±1,4 e 34,4±1,9 g L-1 e para células imobilizadas foram 33,1±0,7; 37,2±0,6 e 36,6±0,4 g L-1, para o primeiro, segundo e terceiro ciclos sequenciais, respectivamente. O maior valor de produtividade e de rendimento do ácido propiônico nas fermentações do sorbitol foi obtido para o primeiro ciclo com células livres: 0,60 g L-1 h-1 e 0,613 g g-1, respectivamente. As concentrações finais de ácido propiônico para as fermentações da sacarose com células livres foram 33,4±0,3; 31,3±0,9 e 31,1±0,1 g L-1 e para células imobilizadas foram 26,9±0,6; 29,1±0,3 e 29,5±0,8 g L-1 para o primeiro, segundo e terceiro ciclos sequenciais, respectivamente. A produtividade e o rendimento do ácido propiônico foram maiores no primeiro ciclo para células livres: 0,48 g L-1 h-1 e 0,409 g g-1, respectivamente. Foram realizadas co-fermentações de glicose:glicerol em duas razões mássicas (1:1 e 2:1) em batelada utilizando P. acidipropionici livre e imobilizada em montmorilonita K10. Apenas nas co-fermentações foi observada a produção do ácido lático e trealose além dos ácidos acético, succínico e propiônico. A maior concentração final de ácido propiônico foi obtida para as co-fermentações glicose:glicerol de razão mássica 2:1 com células de P. acidipropionici livres (31,4±0,3 g L-1) e a menor concentração final foi obtida nas co-fermentações de razão mássica 1:1 para células imobilizadas (23,9±0,8 g L-1). O ácido acético foi produzido apenas nas co-fermentações de razão mássica 2:1 para células livres (0,3±0,4 g L-1) e imobilizadas (1,1±0,2 g L-1). A maior concentração final de ácido lático foi obtida nas co-fermentações de razão mássica 1:1 para células livres (10,5±0,3 g L-1) e a menor concentração final foi obtida nas co-fermentações de razão mássica 2:1 para células livres (0,9±0,6 g L-1). A maior concentração final de trealose foi obtida nas co-fermentações de razão mássica 2:1 para células imobilizadas (12,1±0,1 g L-1) e a menor concentração final foi obtidas nas co-fermentações de razão mássica 2:1 para células livres (6,7±1,0 g L-1). O maior valor de produtividade e de rendimento do ácido propiônico foram obtidos nas co-fermentações de razão mássica 2:1 para células livres: 0,45 g L-1 h-1 e 0,412 g g-1, respectivamente
Abstract: Batch fermentations of sorbitol, sucrose, glycerol and glucose by free cells of Propionibacterium acidipropionici were conducted in bioreactors. Sorbitol fermentations yield the major final propionic acid concentration (39.5±5.2 g L-1) while glucose fermentations yield the minor result (23.9±2.1 g L-1). Only glycerol fermentations yield n-propanol (1.7±0.1 g L-1), furthermore, acetic acid was not generated in glycerol fermentations. In the other hand, sucrose fermentations yield great acetic acid final concentration (10.9±0.0 g L-1). The major propionic acid productivity was got in sorbitol fermentations (0.60 g L-1 h-1). Sorbitol and sucrose batch fermentations by free and immobilized cells of P. acidipropionici in montmorillonite K10 were carried out in three sequential cycles with cell reuse. The final propionic acid concentrations to sorbitol with free cells were 39.5±5.2; 35.8±1.4 e 34.4±1.9 g L-1 and with immobilized cells were 33.1±0.7; 37.2±0.6 e 36.6±0.4 g L-1, to the first, second and third sequential cycles, respectively. The major propionic acid productivity was got in the first cycle with free cells to sorbitol fermentations (0.60 g L-1 h-1). The major propionic acid yield was 0.613 g g-1 in the first cycle to free cells. The final propionic acid concentrations to sucrose fermentations with free cells were 33.4±0.3; 31.3±0.9 e 31.1±0.1 g L-1 and to immobilized cells were 26.9±0.6; 29.1±0.3 e 29.5±0.8 g L-1 to the first, second and third sequential cycles, respectively. The propionic acid productivity was major in the first cycle to free cells (0.48 g L-1 h-1). The major propionic acid yield was 0.409 g g-1 in the first cycle to free cells. Batch co-fermentations of glucose and glycerol were also conducted in two different mass ratios (1:1 and 2:1 glucose:glycerol) by P. acidipropionici free and immobilized in montmorillonite K10. The major propionic acid final concentration was got in glucose:glycerol 2:1 mass ratio co-fermentations by free cells (31.4±0.3 g L-1) while the minor final concentration was got with co-fermentation 1:1 mass ratio to immobilized cells (23.9±0.8 g L-1). Acetic acid was got only in co-fermentations 2:1 mass ratio to free (0.3±0.4 g L-1) and immobilized (1.1±0.2 g L-1) cells. The major propionic acid productivity was got in co-fermentations 2:1 mass ratio to free cells (0.45 g L-1 h-1). The major propionic acid yield was got in co-fermentations 2:1 mass ratio to free cells (0.412 g g-1). Only co-fermentations yield lactic acid and trehalose. The major lactic acid final concentration was got in co-fermentations 1:1 mass ratio to free cells (10.5±0.3 g L-1) and the minor final concentration was got in co-fermentations 2:1 mass ratio to free cells (0.9±0.6 g L-1). The major trehalose final concentration was got in co-fermentations 2:1 mass ratio to immobilized cells (12.1±0.1 g L-1) and the minor final concentration was got in co-fermentations 2:1 mass ratio to free cells (6.7±1.0 g L-1)
Doutorado
Engenharia de Processos
Doutora em Engenharia Quimica
24
Liao, Yu-Hua. "Polymerase chain reaction based cloning of acetate kinase in Propionibacterium acidipropionici /". Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1072778140.
Pełny tekst źródła
25
Meurice, Guillaume. "Reconstruction in silico de voies métaboliques : application aux voies glycolitiques de Propionibacterium freudenreichii subsp. shermanii". Rennes, Agrocampus Ouest, 2004. http://www.theses.fr/2004NSARI041.
Pełny tekst źródłaStreszczenie:
Depuis la dernière décennie, la recherche en microbiologie fait face à un véritable changement qualitatif et quantitatif avec l’émergence de la génomique (qui concerne les génomes et leur analyse) et le développement de la biologie à haut débit (tous les ʺomiquesʺ). Ce changement permet d’aborder l’étude du fonctionnement cellulaire (voies de signalisations, voies métaboliques) dans sa globalité, et non plus par l’étude individuelle de ses acteurs biologiques. Dans le cadre de cette thèse, nous nous intéressons à la reconstruction des voies métaboliques d’une bactérie d’intérêt agro-alimentaire, Propionibacterium freudenreichii subsp. Shermanii (P. Shermanii), à partir de l’analyse de son génome. La problématique de la reconstruction de voies métaboliques est double. D’une part, il faut pouvoir identifier les fonctions enzymatiques présentes dans l’organisme, ce qui se traduit par l’analyse du génome de P. Shermanii. D’autre part, il s’agit de reconstruire le réseau des voies métaboliques à partir des fonctions enzymatiques précédemment identifiées. Après avoir mis en place des méthodologies et des outils bioinformatiques permettant d’analyser les données génomiques de P. Shermanii, nous en avons reconstruit manuellement et automatiquement les voies glycolytiques (glycose et pentose phosphates).
26
Cousin, Fabien. "Le premier lait fermenté exclusivement par une bactérie propionique laitière : mise au point et potentiel probiotique". Rennes, Agrocampus Ouest, 2012. http://www.theses.fr/2012NSARI066.
Pełny tekst źródłaStreszczenie:
Les bactéries propioniques laitières sont principalement utilisées comme levain d’affinage dans des fromages à pâte pressée cuite tels que l’emmental. De plus, des propriétés probiotiques ont été décrites pour ces bactéries. Certaines de ces propriétés nécessitent que les bactéries propioniques laitières arrivent en nombre suffisant et métaboliquement actives dans le côlon. A ce jour, il n'existe pas de produit laitier fermenté permettant d'étudier spécifiquement les effets bénéfiques des bactéries propioniques laitières. La matrice laitière protégeant les probiotiques des stress subis dans le tractus digestif, un lait fermenté exclusivement par une bactérie propionique laitière permettrait d’étudier le potentiel probiotique de cette bactérie. L’objectif de cette thèse était de mettre au point un produit laitier fermenté exclusivement par une bactérie propionique laitière et de le tester comme vecteur d’apport pour étudier les propriétés probiotiques de ces bactéries. Un nouveau lait fermenté exclusivement par une bactérie propionique laitière, dont la population a atteint 109 bactéries par millilitre, a ainsi été développé. Il a protégé efficacement les bactéries des stress digestifs in vitro et in vivo. Il a induit l’apoptose (suicide cellulaire programmé) de cellules cancéreuses humaines coliques et gastriques in vitro. Ce lait fermenté a présenté également un potentiel immunomodulateur in vitro et in vivo, en faveur d’un profil anti-inflammatoire. Un outil performant d'étude du potentiel bénéfique des bactéries propioniques laitières est maintenant disponible pour la communauté scientifique. Il permettra d'explorer les bénéfices de ces bactéries vis-à-vis de la santé, suggérés in vitro, dans des études précliniques et cliniquesDairy propionibacteria are mainly used as ripening starters in Swiss-type cheeses such as Emmental cheese. Moreover, probiotic properties have been described for these bacteria. Some of these effects require high populations of live and metabolically active dairy propionibacteria in the colon. To date, no fermented dairy product exists to study specifically the beneficial effects of these bacteria in the colon. As dairy matrix protects probiotics from stresses undergone in the digestive tract, a milk exclusively fermented by dairy propionibacteria would allow to explore its probiotic potential. The aim of this thesis was to develop a milk exclusively fermented by a dairy propionibacterium and to test it as a probiotic vehicle to study the probiotic properties of this bacterium. A new milk exclusively fermented by dairy propionibacteria, in which the bacteria population reached 109 bacteria per milliliter, has been designed. It protected propionibacteria from digestive stresses in vitro and in vivo. It induced apoptosis (programmed cell death) in human colon and gastric cancer cells in vitro. This fermented milk also displayed an immunomodulatory potential in vitro and in vivo, in favor of an anti-inflammatory pattern. A powerful tool to study the potential benefits of dairy propionibacteria is now available for the scientific community. It will allow to explore the health benefits of these bacteria, suggested in vitro, in preclinical and clinical studies
27
Silva, José Bruno Nunes Ferreira da. "Avaliação da atividade imunomoduladora de Propionibacterium acnes em animais submetidos à sepse letal e perfuração do ceco (CLP)". Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/12238.
Pełny tekst źródłaStreszczenie:
Submitted by Chaylane Marques (chaylane.marques@ufpe.br) on 2015-03-12T18:18:54Z
No. of bitstreams: 2
DISSERTACAO JOSE BRUNO NUNES F SILVA1.pdf: 1053159 bytes, checksum: a48e447775ceb490115f967616656248 (MD5)
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)Made available in DSpace on 2015-03-12T18:18:54Z (GMT). No. of bitstreams: 2 DISSERTACAO JOSE BRUNO NUNES F SILVA1.pdf: 1053159 bytes, checksum: a48e447775ceb490115f967616656248 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-03-30
CAPES
Sepse é uma resposta inflamatória sistêmica que apresenta falha na resposta imune do hospedeiro associado à infecção. Propionibacterium acnes é uma bactéria conhecida por sua atividade imunomoduladora in vitro e in vivo. Neste estudo, foi avaliado o efeito da P. acnesinativada por fenol, na formulação comercial Imunoparvum®, sobre a infecção polimicrobiana induzida por ligadura e perfuração cecal (CLP). Camundongos albinos suíços machos (Mus musculus) foram divididos em 5 grupos (n=8-16/grupo). A administração de salina 0,9% (grupo controle S-CLP) ou Imunoparvum®(grupo tratado) foi realizada 1, 3, 5 e 7 dias antes da CLP. A CLP foi realizada no oitavo dia. A taxa de sobrevida foi analisada com oito animais de cada grupo.Para determinação do número de células peritoneais, citocinas, contagem bacteriana e MPO, os animais foram sacrificados 6 h após a indução de sepse e tiveram a cavidade peritoneal lavada com PBS + EDTA. O grupo tratado comImunoparvum®mostrou aumento da taxa de sobrevivência de 50% em 96 horas. O tratamento com Imunoparvum®casusou um aumento na migração celular para o peritôneo, induziu uma significante redução no lavado peritoneal da citocinas pró-inflamatórias TNF-α, MCP-1 e a citocina antiinflamatória IL-10 (TNF-α de 112,89±7,31pg/mL para 61,04±18,93 pg/mL, MCP-1 de 1321,98 ± 3,84 pg/mL para 778,89±1,24 pg/mL e IL-10 de 1837,41 ± 173,87 pg/mL para 718,80 ± 47,52 pg/mL). Por outro lado, houve um aumento nas concentrações de IL-6 (de 340,33 ± 11,48 pg/mL para 416,89 ± 8,14 pg/mL) no grupo tratado em relação ao controle. Não houve diferença nos níveis de mieloperoxidase (MPO) no pulmão dos animais do grupos Imunoparvum® e controle. O tratamento com Imunoparvum® reduziu o número de bactérias viáveis na cavidade peritoneal. De acordo com os resultados, Imunoparvum®promoveu o aumento da taxa de sobrevida de animais com sepse, em parte atribuída às suas propriedades imunomoduladoras, importantes no combate de microorganismos patogênicos, bem como ao melhor comtrole da infecção através da redução da contagem bacteriana.
28
Figueira, Aburjaile Flavia. "Mécanismes moléculaires de la survie à long terme chez Propionibacterium freudenreichii". Thesis, Rennes, Agrocampus Ouest, 2015. http://www.theses.fr/2015NSARB273/document.
Pełny tekst źródłaStreszczenie:
Propionibacterium freudenreichii est une bactérie très utilisée par l’industrie laitière. Elle appartient aux Actinomycètes connus pour leur survie pendant de longues périodes, dans des conditions environnementales défavorables. Pour mieux comprendre ce phénomène, la caractérisation phénotypique de 8 souches de P. freudenreichii a été réalisée sur 11 jours dans un milieu en carence nutritionnelle. Le taux de survie bactérienne a été mesuré par densité optique, par énumération et évaluation de la viabilité cellulaire. En outre, l’absence de lyse cellulaire a été évaluée par PCR quantitative. La croissance de P. freudenreichii a été décrite en phases exponentielle, stationnaire, stationnaire tardive et survie à long terme.Dans nos conditions expérimentales pendant la période de survie à long terme, les bactéries sont restées viables. La caractérisation phénotypique a montré que P. freudenreichii CIRM-BIA138 était la plus résistante à la carence nutritionnelle et entrait dans un état viable mais non-cultivable. Cette souche a été utilisée pour une étude fonctionnelle par RNA-Seq ainsi que pour des analyses biochimiques sur les surnageants de culture, en phases exponentielle et stationnaire. L’association de ces données transcriptomiques et métabolomiques a permis de déduire les stratégies impliquées dans la survie de cette bactérie. La préparation à l’état de dormance, la diminution du métabolisme et l’utilisation de sources alternatives d’énergie semblent impliquées dans l’adaptation et la persistence de P. freudenreichii CIRM-BIA138 en carence nutritionnelle durant de longPropionibacterium freudenreichii is a dairy bacterium belonging to the Actinobacteria group, which is known to survive for long periods in harsh environmental conditions. In order to investigate the long-term survival phenomenon in P. freudenreichii, 8 strains were phenotypically characterized for a period of 11 days in nutrient shortage condition. Bacterial survival rate was assessed by optical density, CFU counting and live-dead cellular viability. In addition, the absence of cell lysis was evaluated by quantitative PCR. P. freudenreichii growth phases were classified as exponential, stationary, late stationary and long-term survival. Moreover, it was observed that bacterial viability was maintained during long-term survival.Phenotypical characterization indicated that P. freudenreichii CIRM-BIA138 was more resistant to nutrient shortage being able to enter into a viable but nonculturable dormant state. In addition, functional studies of this strain were conducted by RNA-Seq on cultures sampled in exponential and stationary growth phases. Concomitantly, several biochemical analyses were carried out on the culture supernatant. An integrative approach of metabolomic and transcriptomic data allowed us to infer strategies associated with the survival of this bacterium, such as preparation for the dormant state, slow down of metabolic activity and utilization of alternative sources of energy, which altogether might allow P. freudenreichii CIRM-BIA 138 to adapt and persist through nutrient shortage for long periods
29
Ryan-Kewley, Angela E. "Microbial ecology of Propionibacterium acnes in patients undergoing treatment with isotretinoin". Thesis, University of Lincoln, 2011. http://eprints.lincoln.ac.uk/6073/.
Pełny tekst źródłaStreszczenie:
Following failure to respond to antibiotic therapy, 56 patients (mean age 22yrs; range 15-46yrs) with recorded active Acne vulgaris were treated with a standard course of isotretinoin (1mg/kg body weight for 16 weeks). This study investigated the recovery and analysis of skin surface organisms from several skin sites at the start of treatment, 8 weeks into treatment, at the end of the course and 1 month post treatment. The number of anaerobic isolates - presumptive Propionibacterium acnes and also aerobic isolates recovered by appropriate media from each of three specific sites per patient were compared with age-matched controls of healthy volunteers. Patients and controls exhibited similar total numbers of organisms on the cheek, nares and toe web before treatment. Following treatment with isotretinoin the majority of patients had a significant reduction in bacterial numbers (1-2 orders of magnitude) on the cheek. Numbers in the nares and toe web did not show this reduction. Isotretinoin has no antibacterial activity in vitro or in vivo so the observed reduction would strongly suggest that the effect is mediated through alteration of the skin nutritional micro-environment. The clinic-based patients demonstrated high levels of isolates with antibiotic resistance from the outset; the resistance status of each patients’ skin microbiota was determined before, during and after treatment and the dynamics of the population from these sites was investigated. Previous studies of the nature of skin organisms and of the complex multifactorial mechanisms that lead to the eruption of acne have shown that P. acnes play a significant but as yet poorly explained role in the pathogenesis of the disease although it is traditionally the target organism for anti-acne therapy. The clinical samples were cultured using conventional methods to confirm the presence of P. acnes and staphylococci. Novel modifications of PCR amplification methodology were developed to enhance the detection of specific organisms. New protocols for comprehensive and detailed RAPD-PCR analysis of whole cell PCR were developed and employed to profile recovered isolates from individual patients before and after clinical treatment. RAPD-PCR proved to be a useful tool to survey changing bacterial profiles within the cohort. Isolates from some patients were highly similar to each other at the outset, but displayed increased diversity by the end of therapy. Interestingly, other studies have linked clonal populations of bacteria with high pathogenicity. Some patients appear to have acquired a strain which was not evident at their original sampling, but was present in other patients attending the same clinic. P. acnes persist in the environment and may be found on many inanimate objects, from where they could become a source for transmission. As there is some evidence of acquisition of strains from the environment, this is of considerable significance to the management of dermatology clinics throughout the country.
30
De, Annunzio Sarah Raquel. "Atividade antimicrobiana sinérgica da terapia fotodinâmica e tetraciclina contra Propionibacterium acnes /". Araraquara, 2017. http://hdl.handle.net/11449/152524.
Pełny tekst źródłaStreszczenie:
Orientador: Carla Raquel FontanaBanca: Ilana Lopes Baratella da Cunha Camargo
Banca: Juliana Cabrini Carmello
Resumo: A Acne vulgar é uma das mais comuns doenças dermatológicas atingindo adolescentes e adultos. A principal causadora da acne é a infecção pela bactéria Propionibacterium acnes (P. acnes). Atualmente, as opções de tratamento para acne vulgar são numerosas, porém muitas vezes com extensos efeitos colaterais. Fatores como resistência aos antibióticos, e a ação inicial lenta das terapias tópicas têm levado pesquisadores a buscar tratamentos alternativos. Desta forma, o presente estudo objetivou avaliar a eficácia da inativação fotodinâmica mediada por curcumina dissolvida em caldo (TrypcticSoyBroth) TSB e solução de sacarose 0,5% e a combinação dessa terapia com a tetraciclina, contra P. acnes em fase planctônica e biofilme. A viabilidade celular foi avaliada através da quantificação das colônias formadas por mililitro de amostra (UFC/mL). A concentração bactericida mínima (CBM) da tetraciclina sobre P. acnes foi determinada através do método de microdiluição em caldo. Foi realizada a avaliação da biomassa total e inibição da formação do biofilme através do método de coloração por cristal violeta 0,5%. A análise estatística dos dados foi feita através do teste de Análise de Variância (oneway ANOVA) com pós-teste de Tukey. Os resultados do presente estudo mostraram que a terapia fotodinâmica antimicrobiana (TFDa) mediada por curcumina foi eficiente na redução microbiana quando realizada a quantificação das colônias formadas, comparada ao grupo controle negativo em forma planctônica ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Acne vulgar is one of the most common dermatological and adult diseases. The main cause of acne is an infection by the bacterium Propionibacterium acnes (P. acnes).Currently there are many treatment options for acne vulgaris, although often with extensive side effects. Factors such antibiotics resistance and slow initial action of topical therapies that led researchers to seek alternative treatments. Thus, the present study aimed to evaluate the efficacy of curcumin-mediated photodynamic inactivation in broth (Tryptic Soy Broth) TSB and 0.5% sucrose solution and the combination of this therapy with tetracycline against planktonic phase P. acnes and biofilm. Cell viability was evaluated by quantification of the colonies formed per milliliter of sample (CFU / mL). The minimum bactericidal concentration (MBC) of tetracycline over P. acnes was determined by the broth microdilution method. The evaluation of the total biomass and inhibition of the formation of the biofilm was performed through the method of staining by violet crystal 0.5%. The statistical analysis of the data was done through the variance analysis (ANOVA one way) test with Tukey's post test. The results of this study showed that curcumin-mediated photodynamic antimicrobial therapy (TFDa) was efficient in microbial reduction when quantification of the colonies was performed, compared to the negative control group in planktonic form as well as in biofilm both diluted in TSB broth and in solution sucrose 0.5% being able to reduce all bacterial load. A reduction of more than 28% of the total biofilm biomass and an inhibition of more than 70% was achieved after treatment. It was possible to conclude that curcuminmediated TFDa dissolved in TSB broth and 0.5% sucrose solution was efficient for the total reduction of the planktonic and biofilm microbial load. Curcumin... (Complete abstract click electronic access below)
Mestre
31
Liao, Yu-Hua. "Polymerase chain reaction based cloning of acetate kinase in propionibacterium acidipropionici". The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1072778140.
Pełny tekst źródła
32
Murano, Elsa Alina. "Role of polymorphonuclear leukocytes in the tumoricidal activity of Propionibacterium acnes". Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/50069.
Pełny tekst źródłaStreszczenie:
The mechanism responsible for the killing of tumor cells after injection of mice with a mixture of tumor cells and Propionibacterium acnes were investigated. Tumor cells were injected intramuscularly into Balb/c mice either alone or together with P. acnes vaccine. The tumor cells were then removed from the injection site 12 hours after injection, and transferred into fresh mice. Tumor cells from control animals given tumor cells only caused tumors when transferred into fresh mice 12 hours after injection whereas tumor cells from animals given both tumor cells and vaccine did not develop tumors in the fresh nice.
ELISA tests were done to estimate the number of tumor cells in the lesions. In control animals given 10⁵ tumor cells the estimated numbers dropped to 10³ cells at 24 hours, but thereafter rose steadily. Palpable tumors were present 7-10 days later. In animals given 10⁵ tumor cells + 500 ug of P. acnes vaccine, estimated tumor cell numbers fell steadily, and could not be detected after 2 days. Palpable tumors never developed in these animals. These results indicate that tumor cells are killed, or rendered nontumorigenic, during the first 12 hours after co-injection into mice with P. acnes
Histological studies showed that injection of P. acnes vaccine, with or without tumor cells, induced large numbers of polymorphonuclear leukocytes (PMNs) at 12 hours. To determine the role of PMNs in the killing of tumor cells, tumor cells were incubated with supernatant obtained from the phagocytosis mixture of PHNs and P. genes. After a 2- hr. incubation, the tumor cells were washed and injected into fresh mice. No tumors developed, indicating that a product of the phagocytosis of P. acnes by PMNs played a role in the killing of tumor cells. Bacterial vaccines such as P. freudenreichii, which are poorly protective against tuner cells, produced phagocytosis supernatants which were unable to kill tumor cells.
Various oxygen radical scavengers/inhibitors were used to test their effect on the toxicity of the supernatant on tumor cells and chinese hamster ovary cells. Both azide and catalase rendered the supernatant nontoxigenic, suggesting that H₂O₂, produced by PHNs during phagocytosis of P. acnes, is responsible for the killing of tumor cells. However, the addition of catalase 30 minutes after the start of phagocytosis had no effect on the toxicity of the supernatant, suggesting that H₂O₂ is converted to other toxic radicals during the course of phagocytosis of P. acnes by PMNs.
The oxygen consumption levels of PHNs during phagocytosis of P. acnes or other bacterial vaccines was measured and found to be similar regardless of the antitumor ability of the vaccine used. This suggests that the difference in the ability of various vaccines to protect mice against tumors may be in the production of a particular oxygen radical by PMNs during phagocytosis, and not in the production of different quantities of the same radicals.Master of Science
incomplete_metadata
33
Jarrousse, Véronique. "Rôle de Propionibacterium acnes dans la différenciation et l'immunité innée kératinocytaire". Nantes, 2006. http://archive.bu.univ-nantes.fr/pollux/show.action?id=7bef751e-1ac8-4cb6-b817-0979934f8e0f.
Pełny tekst źródłaStreszczenie:
L'acné est une maladie chronique du follicule pilo-sébacé sous dépendance hormonale qui se déroule en trois phase: la stimulation de la production de la glande sébacée qui induit une hyperséborrhée débutant en général à la puberté, puis la formation du micro-comédon qui est considéré comme la lésion élémentaire de l'acné et qui se ferait à partir d'anomalies de la prolifération, de l'adhésion et de la différenciation des kératinocytes et, enfin la formation des lésions inflammatoires dans laquelle Propionibacterium acnes (P. Acnes) et l'immunité innée semblent jouer un rôle fondamental. Les Lymphomes Cutanés T Epidermotropes (LCTE) : Mycosis Fongoïde (MF) et Syndrome de Sézary (SS) sont caractérisés par la présence d’un infiltrat important de lymphocytes T CD4+ matures (composé de lymphocytes T réactionnels et tumoraux). L’étiologie des LCTE demeure inconnue toutefois l’implication d’un agent infectieux (EBV, HTLV-1) est fortement suspectée. Notre objectif était d’étudier le rôle de P. Acnes dans l’immunité innée et la différenciation kératinocytaire. Afin d’analyser les effets de P. Acnes sur la différenciation kératinocytaire et l’immunité innée, nous avons mis au point un modèle cutané d’acné en incubant les extraits de P. Acnes (FM : fractions membranaires, SA : surnageant A et SB : surnageant B), soit avec des kératinocytes normaux humains en monocouches, soit avec des explants cutanés. En utilisant ce modèle nous avons étudié l’expression des intégrines 1, 3, 6, V6 et de la filaggrine. Nos résultats suggèrent que P. Acnes joue un rôle important dans les anomalies de la différenciation kératinocytaire puisque cette bactérie induit des modifications de l’expression des intégrines et de l’expression de la filaggrine. Nous avons également montré que l’immunité innée kératinocytaire était activée par P. Acnes : en effet, l’expression du Toll-like Récepteur 2 (TLR2, récepteurs de l’immunité innée) par les kératinocytes est stimulée par l’extrait FM en particulier. Le zinc est utilisé par les dermatologues pour le traitement de l’acné de type inflammatoire minime à modérée. La pluralité du mode d’action anti-inflammatoire du zinc n’est que partiellement connue. Nos résultats montrent que le zinc inhibe l’expression de TLR2 lorsque celle-ci est induite par l’extrait FM de P. Acnes. Cette inhibition n’est pas liée à une modification de l’expression de NF-B ou de l’interleukine-8. Ainsi, P. Acnes semble jouer un rôle clé dans la physiopathologie de l’acné en agissant sur les kératinocytes dès l’étape du microcomédon jusqu'à la réaction inflammatoire. En parallèle, nous avons étudié les modulations de l’immunité innée dans une pathologie cutanée inflammatoire ou un agent infectieux est suspecté : les LCTE. Nous avons montré que les profils d’expression des TLRs 2, 4 et 9 au sein des MF étaient différents de ceux observés au cours du SS : en effet la totalité des MF étudiés exprime ces trois TLRs dont un tiers très fortement tandis qu’un tiers des SS étudiés n’exprime pas du tout TLRs 2,4 et 9. En conclusion, nous démontrons que l’expression des TLRs 2, 4 et 9 est augmentée dans l’épiderme de patients MF. Cette activation par un agent infectieux pourrait jouer un rôle dans l’induction et le maintien de l’infiltrat de lymphocytes T dans les lésions cutanées de mycosis fungoïde et du syndrome de SézaryThe aim of this work was to determinate the effects of Propionibacterium acnes in keratinocytes differentiation and innate immunity. Our results suggest that P. Acnes play a part in abnormal keratinocytes differentiation indeed P. Acnes extract modulate integrins and filaggrin expression. We also show that FM P. Acnes extract induce TLR2 expression. Zinc could partially inhibit this expression. In conclusion, P. Acnes seems to play an important part in acne physiopathology from microcomedon to the inflammation. Concurrently, we have studied innate immunity modulation in cutaneous T cell lymphoma (CTCL). The origin of this pathology remains unknown but the implication of viruses is highly suspected. We show that TLRs 2, 4 and 9 expressions by keratinocytes was increase in CTCL epidermis compare to normal skin. Furthermore TLRs 2, 4 and 9 pattern expression in MF skin was different to that observed in SS skin. In conclusion, the activation of TLRs 2, 4 and 9 by an infectious antigen could play a role in the chronic activation of T lymphocytes in the skin of CTCL patients
34
Limpisathian, Patcharee. "Characterization of the interaction between Lactobacillus helveticus and Propionibacterium in Swiss Cheese". Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1123789201.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvii, 143 p.; also includes graphics. Includes bibliographical references (p. 106-111). Available online via OhioLINK's ETD Center
35
Calderón, Luige Armando Llerena 1986. "Estudo de otimização das condições da fermentação para produção de ácido propiônico por Propionibacterium acidipropionici utilizando xarope de cana-de-açúcar". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314278.
Pełny tekst źródłaStreszczenie:
Orientador: Gonçalo Amarante Guimarães PereiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-21T20:10:33Z (GMT). No. of bitstreams: 1 Calderon_LuigeArmandoLlerena_M.pdf: 3485086 bytes, checksum: 33f779fcd9679f472303314b64f35d8d (MD5) Previous issue date: 2012
Resumo: O ácido propiônico possui grande importância para a economia devido às suas diversas aplicações nas indústrias químicas e alimentícias. Atualmente, ele é produzido a partir de derivados do petróleo, mas as atuais preocupações ambientais relacionadas às emissões de carbono provenientes de fontes fósseis tornam a sua produção por rotas biológicas e fontes renováveis um processo cada vez mais atraente. O ácido propiônico também pode ser produzido a partir do metabolismo heterofermentativo da Propionibacterium acidipropionici. Embora existam diversos estudos que visem à otimização do processo de produção de ácido propiônico por rotas biológicas, ainda não existe nenhum processo eficiente que possa ser escalonado a um nível industrial. Consequentemente, o foco deste trabalho está no uso de ferramentas de planejamento experimental para a produção de ácido propiônico a partir de xarope de cana-de-açúcar (caldo de cana-de-açúcar concentrado), levando-se em conta três respostas de extrema importância para este bioprocesso: rendimento, produtividade volumétrica e a resposta de menor formação de ácido succínico (RMS). Na primeira parte do trabalho foi realizada a adequação de um método cromatográfico para a quantificação dos açúcares presentes no xarope de cana-de-açúcar, a identificação da linhagem P. acidipropionici ATTC 4875 como a mais adequada para a produção de ácido propiônico e o estudo do papel do extrato de levedura como fonte de nitrogênio para o meio de cultura. Utilizando-se o delineamento experimental Plackett & Burman, foram estudados 8 fatores com o objetivo de avaliar a sua importância no processo. Dos 8 fatores, três (temperatura, concentração de extrato de levedura e concentração de xarope de cana-de-açúcar) foram selecionados por apresentarem influência significativa no processo de produção de ácido propiônico. Em uma segunda etapa, utilizando um delineamento composto central rotacional (DCCR), foram determinados os valores ótimos desses fatores como sendo 35 ºC de temperatura, 22 g/L de extrato de levedura e 54 g/L de concentração de xarope de cana-de-açúcar. Com estas condições, obteve-se um rendimento de 47% (m/m), uma produtividade volumétrica de 0,89 g/L. h e uma RMS de 94%. Estes resultados significaram um incremento de 5%, 196% e 8% no rendimento, na produtividade volumétrica e na RMS, respectivamente, quando comparados à condição de cultivo inicial
Abstract: Propionic acid is of great importance for economy because of its variety of applications in the chemical and food industries. It is currently produced from petroleum, but due to environmental concerns related to carbon emissions from fossil fuels the production based on renewable biological routes is becoming more attractive. Propionic acid can be produced through the heterofermentative metabolism of Propionibacterium acidipropionici. Despite the existence of several studies aimed at optimization of propionic acid production through biological routes, no efficient process that can be scaled up to an industrial level has been developed yet. Consequently, the goal of this project is the use of chemometric tools for the production of propionic acid from sugar cane syrup (concentrated sugar cane juice), taking into account three responses of extreme importance to an industry level process: yield, volumetric productivity and the response of lowest succinic acid formation (RMS). The first steps were the adaptation of a chromatography method for the quantification of sugars present in sugar cane syrup, the identification of strain P. acidipropionici ATCC 4875 as the most suitable organism for propionic acid production and the role of yeast extract as a nitrogen source in the culture medium. Using the experimental design method, developed by Plackett and Burman, 8 factors were evaluated to assess their importance in the process. Three of these eight factors (temperature, yeast extract concentration and sugar cane syrup concentration) were selected because of their significant influence on propionic acid production. In a second step, central composite design (CCD) was used to determine the optimum values of these factors, being 35°C for temperature, 22 g/L of yeast extract and 54 g/L of sugar cane syrup. Under these conditions, a yield of 47% (w/w), a volumetric productivity of 0.89 g/L. h and a RSM of 94% were obtained. These results represented an increase of 5%, 196% and 8% in yield, volumetric productivity and RMS, respectively, compared to the initial culture condition
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
36
Gardner, Nancy. "Production d'acide propionique sur un milieu riche en extraits de levure". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/MQ40583.pdf.
Pełny tekst źródła
37
Carpentier, Jean. "Variabilité moléculaire et mode évolutif du gène de virulence Gp-Rbp-A et du co-Facteur RanGap2 impliqués dans l’interaction incompatible entre le nématode Globodra pallida et la pomme de terre Gpa2 résistante". Rennes, Agrocampus Ouest, 2012. http://www.theses.fr/2012NSARC105.
Pełny tekst źródłaStreszczenie:
Afin de lutter contre le nematode à kyste de la pomme de terre, Globodera pallida, l’utilisation de variétés résistantes est maintenant préconisée. Cependant la plupart des gènes de résistances connus, comme le gène majeur Gpa2 ne sont efficaces que vis-à-vis d’un nombre réduit de populations. De plus Gpa2 nécessite la présence d’un co-facteur, RanGAP2, pour reconnaître la protéine d’avirulence du nématode codée par le gène Gp-Rbp-1 et déclencher alors les mécanismes de défenses de la plante. L’objectif de cette étude est de caractériser le spectre d’e efficacité de Gpa2 vis-à-vis de populations de G. Pallida originaires d’Europe et d’Amérique du Sud (bassin d’origine du nématode) et de décrire la variabilité moléculaire et fonctionnelle de Gp-Rbp-1 et chez Gp-Rbp-1 qui pourrait affecter l’interaction ave Gpa2 et du polymorphisme chez RanGAP2 qui pourrait être utilisé pour élargir le spectre d’action du gène Gpa2. Nous avons montré que la sensibilité d’un cultivar de pomme de terre exprimant Gpa2 à une population de G. Pallida ne pouvait être expliquée exclusivement par la fréquence de variants avirulents de Gp-Rbp-1 dans cette population de nématodes. De plus parmi les huit sites de Gp-Rbp-1 détectés sous slection positive, la seule variation d’acide mainé en position 187 (proline/sérine) s’est avérée suffisante pour expliquer la reconnaissance de GP-RBP-1 par GPA2. Malgré de nombreux sites détectés sous sélection purifiante, RanGAP2 présente deux sites polymorphes (acides aminés 106 et 237) et une insertion/délétion d’intérêt. La variabilité au niveau de ces sites ne permet pas la reconnaissance des variants virulents (non reconnus ) de GP-RBP-1 par GPA2 mais semble néanmoins affecter l’intensité de la réaction d’hypersensibilité qui se produits lors de lla reconnaissance des variants avirulents de GP-RBP-1 par GPA2In order to control the potato cyst nematode. Globodera pallida, using resistant varieties is now advocated. Nevertheless, most of the resistance genes, including ther major gene Gpa2 are efficient only against a lim ited number of nematode populations. Moreover Gpa2 needs the presence of a co-factor – RanGAP2 – to recognize the nematode avirulence protein coded by the Gp-RBP-1 gene and to trigger the plant defence mechanisms. The present work aims to characterize the efficiency spectrum of Gpa2. Our goals were to identify the Gp-Rbp-1 polymorphisms affecting the outcome of the interaction with Gpa2 and the polymorphisms in RanGAP2 that can be used to expand the range of G. Pallida populations controlled by Gpa2. We have shown tha susceptibility of a potato cultivar expressing Gpa2 to a G. Pallida population. Furthermore, among the eight sites of Gp-Rbp-1 found under positive selection, the sole variation at amino acid position 187 (proline/serine) remained sufficienet to explain the recognition of GP-RBP 1 by GPA2. Despite numerous sites found to have evolved under purifying selection, RanGAP2 have two polymorphic sites (amino acids 106 and 237) and one insertion/deletion of interest. Variability observed at these sites do not enable the recognition of virulent variants (non-recognized) of GP-RBP-1 by GPA2 but seems to affect intensity of the hypersensitive response triggered by the recognition of avirulent variants of Gp Rbp-1 GPA2
38
Aubin, Guillaume. "Phylogénie et tropisme de Cutibacterium acnes : impact sur la réaction inflammatoire et la réaction immunitaire lors des infections sur implant". Thesis, Nantes, 2017. http://www.theses.fr/2017NANT1006/document.
Pełny tekst źródłaStreszczenie:
L’objectif de cette thèse a été d’étudier la physiopathologie des infections à Cutibacterium (anciennement Propionibacterium) acnes). D’un point de vue phylogénique, nous avons démontré par MLST la prédominance des complexes clonaux (CC) 36 et 53 au sein des infections sur prothèse articulaire et celles des CC18 et 28 au sein des isolats responsables d’acné ou d’infection sur matériel rachidien. Grâce à un modèle de Caenorhabditis elegans, nous avons identifié deux groupes de virulence chez C. acnes. Ces groupes n’étaient pas corrélés au CC ou à l’origine clinique des isolats. Les études d’interaction de C. acnes avec les cellules osseuses ont montré que les isolats appartenant au CC36 ne sont pas internalisés par les ostéoblastes et les ostéoclastes contrairement aux isolats appartenant aux CC18/28. Par ailleurs, ces derniers sont capables de persister au sein des ostéoblastes pendant au moins 96 heures. Les souches de C. acnes diminuent in vitro la résorption osseuse avec un effet plus marqué pour les isolats du CC36. L’analyse par séquençage du génome entier a révélé 27 gènes de C. acnes potentiellement liés au phénotype d’internalisation cellulaire. Les études d’interaction de C. acnes avec les cellulaires immunitaire ont révélé, grâce à un modèle de granulome in vitro, que les isolats appartenant au CC36 orientent la réponse immunitaire vers le recrutement de lymphocytes CD8+ alors que les isolats du CC18/28 orientent cette réponse vers le recrutement de lymphocytes CD4+. L’isolat S8 issu d’un ganglion d’un patient atteint de sarcoïdose engendrait la formation d’un plus grand nombre de granulomes. L’étude de souches cliniques de C. acnes résistantes à la rifampicine nous a permis de caractériser sur le plan moléculaire les mutations au sein du gène rpoB responsables de cette résistance. Au décours de ce travail, nous avons identifié et décrit une nouvelle espèce au sein du phylum des Actinobacteria : Propionibacterium namnetense. L’ensemble de ces travaux apporte de nouvelles explications sur le développement des infections à C. acnes à travers le prisme de la phylogénie de cette bactérieUsing a Caenorhabditis elegans model, we identified two virulence groups of C. acnes not linked to their CC or clinical origin. Studies about C. acnes and bone cells interactions showed that CC36 C. acnes strains were significantly less internalized by osteoblasts and osteoclasts than CC18 and CC28 C. acnes strains. The CC18 C. acnes ATCC6919 isolate could survive intracellularly for at least 96 hours. C. acnes significantly decreased the resorption ability of osteoclasts with a major impact by the CC36 strain. Genome analysis revealed 27 genes possibly linked to these phenotypic behaviors. Studies about C. acnes interactions with immune cells revealed, thanks to a granuloma in vitro model, that isolate belonging to CC36 recruits more CD4+ lymphocytes inside the granuloma, whereas isolates belonging to CC18/28 recruit more CD4+ lymphocytes. The S8 strain isolated from the lymph node of a sarcoidosis patient generates more granulomas than other strains (acne and PJI isolates). Clinical strains of C. acnes resistant to rifampicin allowed us to characterize the mutations in the rpoB gene leading to this resistance. During this work, we identified and described a new species among the Actinobacteria phylum: Propionibacterium namnetense. Taken together, these studies provide new explanations about the development of C. acnes infections through the angle of the phylogeny of this bacteria. The aim of this thesis was to study the physiopathology of Cutibacterium (formerly Propionibacterium) acnes infections. From a phylogeny point of view, by MLST, we showed that C. acnes belonging to clonal complexes (CC) 36/53 were associated to prosthetic joint infections (PJI) and CC18/28 C. acnes isolates were linked to acne and spine material infections
39
Oprica, Cristina. "Characterisation of antibiotic-resistant Propionibacterium acnes from acne vulgaris and other diseases /". Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-755-3/.
Pełny tekst źródła
40
Sutcliffe, Iain C. "The lipids and lipoglycan of Propionibacterium freudenreichii and other gram-positive bacteria". Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328137.
Pełny tekst źródła
41
McCafferty, Darragh. "Understanding the role of Propionibacterium acnes in the aetiology of prostate cancer". Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678939.
Pełny tekst źródłaStreszczenie:
Prostate carcinoma represents one of the leading causes of cancer death in men within the Western world, Several studies have hypothesised that chronic prostatic inflammation may predispose men to developing this malignancy. In 2005, the Gram-positive anaerobe, Propionibacterium acnes was identified as the predominant bacterium in cancerous prostate glands; with its pro-inflammatory nature illustrated following acute and chronic infection of such cells both in vitro and in vivo, The main objective of this study was therefore to further elucidate the potential role of p, acnes in the aetiology of prostate cancer. Firstly, the inflammatory response of normal prostate epithelial cells (RWPE-1s), following short-term exposure to a number of P. acnes phylogroups, was examined; with particular interest on the effects of infection on expression of pro-inflammatory molecules, such as PAR-2. Next, long-term infection studies Were performed to evaluate P. acnes persistence, and the mechanisms by which this bacterium stimulates chronic prostatic inflammation. Short-term P. acnes infection potently induced PAR-2 expression in RWPE-1s, as revealed by RT-PCR and Western! immunoblotling; with all strains also found to enhance secretion of inflammatory mediators, including IL-6 and IL-8. Distinct phylotypic differences were noted during these studies; thus underpinning reports of diversity among P. acnes phylotypes. Total viable counts demonstrated the ability of P. acnes to establish chronic RWPE-1 infection; thereby facilitating the induction of sustained prostatic inflammation, achieved through augmentation of PAR-2, and increased release of pro-inflammatory molecules, Moreover, qRT-PCR array analysis revealed P. acnes infection to upregulate many pro-angiogenic genes; a response reflected during in vitro tubule assays upon incubation of HMEC-1 s with conditioned media obtained from P. acnes-infected RWPE-1s. Taken together, the findings obtained these studies highlight prostatic P. acnes infection as a potential risk factor for prostate carcinogenesis, due to the strong inflammatory response that is generated upon exposure to such cells.
42
De, Canha Marco Nuno. "Antimicrobial and anti-inflammatory effect of southern African plants against Propionibacterium acnes". Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/79786.
Pełny tekst źródłaStreszczenie:
Twenty southern African plants were selected based on traditional use. The ethanol extracts were tested for their antimicrobial activity against P. acnes (ATCC 11827) [Propionibacterium acnes (Gilchrist) Douglas and Gunter deposited as Corynebacterium acnes (Gilchrist) Eberson]. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the extracts were also determined.
Cytotoxicity on human macrophage cells (U937) was performed using the 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) reduction assay. The cytotoxicity was performed to ensure that the extracts are not toxic to human macrophage cells (U937) and to obtain a non-lethal range of concentrations to be tested in the anti-inflammatory assay. The anti-inflammatory potential was tested using IL-8 as a marker cytokine. This is a pro-inflammatory cytokine secreted when cells are stimulated with heat-killed P. acnes cultures.
During the investigation of the antimicrobial activity, four plant extracts were found to have significant inhibitory activity against P. acnes. Helichrysum odoratissimum showed the best activity with a minimum inhibitory concentration (MIC) at 7.81μg/ml. Clausena anisata, Rapanea melanophloeos and Helichrysum kraussii were also active with MICs at 31.25μg/ml, 15.63μg/ml and 125μg/ml, respectively. All MICs were selected based on PrestoBlue as the growth indicator. Helichrysum odoratissimum showed also showed the best antioxidant activity with an IC50 of 3.86 ± 0.24μg/ml. It was also reported to have the best selectivity index (SI) of 2.76 on U937 cells. Clausena anisata exhibited good antimicrobial activity and low toxicity on U937 cells with an IC50 at 74.46μg/ml and an SI of 2.38.
During the investigation of the synergistic activity of the extracts, the combination of 3.13μg/ml of Helichrysum odoratissimum and Helichrysum kraussii at 0.78μg/ml showed better antimicrobial activity of either of the plant extracts acting alone against P. acnes with a fractional inhibitory index (ΣFIC) of 0.42.
Clausena anisata was selected as the extract for the Interleukin-8 (IL-8) inhibition assay as it was shown to be traditionally used for treatment of many inflammatory disorders or symptoms. The inhibition of IL-8 by C. anisata in vitro when plant extract was added to stimulated U937 cells was low but there was some inhibition. The IL-8 protein concentration produced by U937 cells treated with 100μg/ml of heat-killed P. acnes was 840.52pg/ml. Low levels of IL-8 inhibition were observed when cells stimulated with P. acnes were treated with non-lethal concentrations of C. anisata extract. Treatment with 50μg/ml, 25μg/ml, 12.5μg/ml and 6.25μg/ml showed a decrease in IL-8 to 322.48 ± 0.07pg/ml, 365.98 ± 0.24pg/ml, 383.62 ± 0.08pg/ml and 409.52 ± 0.13pg/ml, respectively. The untreated cell control however, seemed to show spontaneous production of IL-8 with quantified as 488.76 ± 0.06pg/ml, making it difficult to analyse effects of other cell stimulants. This spontaneous release was also inhibited with the addition of C. anisata extract at 50μg/ml, 25μg/ml, 12.5μg/ml and 6.25μg/ml which showed IL-8 levels at 299.24 ± 0.13pg/ml, 357.82 ± 0.07pg/ml, 387.14 ± 0.12pg/ml and 388.74 ± 0.19pg/ml, respectively
The use of many polyherbal formulations is becoming popular practice. Due to the variety of symptoms observed with acne vulgaris it would be beneficial to investigate mixtures of plants showing good antimicrobial, antioxidant, anti-inflammatory and anti-pathogenic activity as potential treatments for acne vulgaris.
This is the first report of the synergistic activity of Helichrysum odoratissimum and Helichrysum kraussii crude ethanol extracts used in a synergistic combination. Also the production of hyaluronidase by the tester strain P. acnes (ATCC 11827). The combination and some other active plants shown in the study should be further investigated as possible novel medicinal agents against acne vulgaris.Dissertation (MSc)--University of Pretoria, 2014.
National Research Foundation (NRF)
Plant Science
MSc
Unrestricted
43
Dherbécourt, Julien. "Lipolyse dans le fromage : implication des enzymes de Propionibacterium freudenreichii dans l’emmental". Rennes, Agrocampus Ouest, 2008. http://www.theses.fr/2008NSARI049.
Pełny tekst źródłaStreszczenie:
La lipolyse est l'hydrolyse de la matière grasse par des estérases lipolytiques, classiquement appelées lipaes, et libère des acides gras libres. Ces acides gras sont des composés d'arôme essentiels dans la flaveur de nombreux fromages dont l'emmental, qui est un fromage de poids dans l’économie laitère en France. Propionibacterium fredudenreichii, une espèce bactérienne utilisée comme levain d'affinage, a un rôle majeur dans la lipolyse de l'emmental, mais son implication directe par l'action de ses enzymes dans ce phénomène restait à confirmer. De plus, l'équipement estérasique de P. Freudenreichii n'était que peu documenté. L'objectif de cette thèse était d’identifier les estérases de P. Freudenreichii impliquées dans la lipolyse de l’emmental. Nous avons élaboré la stratégie suivante :: (i) caractériser le potentiel lipolytique de la souche CIP103027T en culture pure et au cours de l'affinage d'emmental (ii) recherche le plus exhaustivement et pertinemment possible, les estérases putatives dans le génome récemment séquencé de cette souche, par une approche génomique novatrice que nous avons développée et (iii) déterminer, parmi ces estérases putatives, les plus susceptibles d'être impliquées dans la lipolyse de l'emmental. Nous avons confirmé que P. Freudenreichii est majoritairement impliqué dans la lipolyse de l'emmental et montré que son implication résulte bien de l'action directe d'une ou plusieurs estérases lipolytiques. Nous avons mis en évidences en culture pure et dans l'emmental qu'au moins une de ces enzymes est capable d'hydrolyser les triglécérides mais aurait une préférence pour les monoglécérides et/ou diglycérides et serait régio-sélective. Nous avons formulé et conforté l'hypothèse que P. Freudenreichii possède au moins une estérase extracellulaire impliquée dans la lipolyse de l'emmental. Dans le génome de la souche CIP103027T, nous avons identifié 12 gènes d'estérases putatives. Ces gènes codent pour 6 estérases actives sur des esters de naphthyl et 6 protéines donc l'activité estérastique reste à tester sur d'autres substratsLipolysis consists in the hydrolysis of fat by lipolytic esterases, usually named lipases, resulting in the subsequent release of free fatty acids. These fatty acids are essential aroma compounds in the flavour of numerous cheeses, including the economically important emmental cheese, in France. Propionibacteriuim freudenreichii a bacterial species used for ripening, plays a major role in the lipolysis of emmental cheese. However its direct involvement by action of its enzyme in this phenomenon remains to be confirmed. Moreover, esterase equipment of P. Freudenreichii was poorly documented. The aim of this PhD thesis was to identify the esterases of P. Freudenreichii,involved in the lipolyisis of emmental cheese. We elaborated the following strategy : (i) to characterise the lipolytic potential of the CIP103027T strain in pure culture and during ripening of emmental cheese, (ii) to seek as exhaustively and pertinently as possible, the putative esterases in the recently sequenced genome of this strain, by an innovative genomic approach we developed, and (iii) to determine, which of these putative esterases are the most susceptible to be involved in the lipolysis of emmental cheese. We confirmed that P. Freudenreichii is the main lipolytic agent in emmental cheese and showed that its role in lipolysis results from the direct action of one or more lipolytic esterases. We highlighted, in pure culture and in emmental cheese, that at least one of these enzymes is able to hydrolyse triacylglycerols. However this(ese) esterase(s) seem(s) to shom a preference for monoacylglycerols and/or diacylglycerols and would be rejioselective. We formulated, then confirmed the hypotheis that P. Freudenreichii possesses at least one extracellular esterase, involved in the lipolysis of emmental cheese. In the genome of CIP103027T strain, we identified 12 putative esterase genes
44
Johnson, Jessica Virginia. "Development of a Microbial Fuel Cell Cocatalyst with Propionibacterium freudenreichii ssp. shermanii". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38450.
Pełny tekst źródłaStreszczenie:
Addressing the low power generation of anodic biocatalysts is pertinent to the advancement of microbial fuel cell technology. While Propionibacterium freudenreichii ssp. shermanii has shown potential as a biocatalyst, its incomplete consumption of the anodic substrate is a persistent issue. This research aims to optimize substrate consumption to increase power generation using Propionibacterium freudenreichii ssp. shermanii as a biocatalyst. The effect of coculturing Geobacter sulfurreducens with Propionibacterium freudenreichii ssp. shermanii was investigated. The cocatalyst and pure culture performance was tested in an air-cathode microbial fuel cell. Geobacter sulfurreducens produced the highest maximum power density among the experimental cases. Power density produced by Propionibacterium
freudenreichii ssp. shermanii was improved in the air-cathode design compared to previous experiments performed in an H-type design. The novel cocatalyst was shown to produce electricity, however a full characterization to elucidate the contribution to power generation by each microbe would be desirable to investigate.
45
Merk, Kathrin. "In-vivo-Porphyrinproduktion von Propionibacterium acnes unter systemischer Aknetherapie mit Isotretinoin und Minozyklin". Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-31015.
Pełny tekst źródła
46
Walker, Michelle. "The prevention of spoilage in fruit juices by alicyclobacillus acidoterrestris and propionibacterium cyclohexanicum". Thesis, University of Northampton, 2006. http://nectar.northampton.ac.uk/2664/.
Pełny tekst źródłaStreszczenie:
During the past two decades several novel spoilage micro-organisms have emerged. Raw materials and products have been contaminated in increasing numbers of spoilage incidents causing widespread problems within the juice and beverage industry. This study investigates two such spoilage micro-organisms, A licyclobacillus acidoterrestris and Propionibacterium cyclohexanicum, both isolated from pasteurised contaminated fruit juice. A variety of media were tested to determine which supported optimal growth of A. acidoterrestris with Orange Serum Agar providing consistently high plate counts. The presence of A. acidoterrestris in raw materials and shelf stable products was monitored and the effects on its growth and survival of temperature, headspace and movement of containers during storage were investigated. The survival of P. cyclohexanicum after pasteurisation was assessed and growth determined at a variety of temperatures. The survival of each bacterium was investigated in different fruit juices, when challenged by the preservatives sodium benzoate and potassium sorbate and the bacteriocin nisin and when grown in the same juice container and co-cultured on the same solid medium. 17% of samples tested were contaminated by A. acidoterrestris; however P. cyclohexanicum was not isolated from any sample. P. cyclohexanicum survived 10 minutes at temperatures of 4°C to 95°C and grew in orange, tomato and pineapple juice while A. acidoterrestris grew in all juices tested. A. acidoterrestris was inhibited by sodium benzoate (500ppm), potassium sorbate (500ppm) and nisin (51U/ml). P. cyclohexanicum, although not inhibited by nisin (1000IU/ml), was susceptible to sodium benzoate (500ppm) and potassium sorbate (l000ppm). I-Ieadspace, movement of containers and storage temperatures affected detection rates of A. acjdoterrestrjs. Co-cultures demonstrated that if found within the same enviromnent, both bacilli can survive and cause spoilage. A. acidoterrestris is a world wide contaminant within the soft drinks industry and, considering the results of these studies P. cyclohexanicum with its heat resistance and tolerance to nisin may also emerge as a major spoilage microorganism
47
Sampaio, Romildo Martins. "Estudo da produção de vitamina B12 por bacterias dos generos propionibacterium e pseudomonas". [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255441.
Pełny tekst źródłaStreszczenie:
Orientador: Ranulfo Monte AlegreTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-07-28T14:47:55Z (GMT). No. of bitstreams: 1 Sampaio_RomildoMartins_D.pdf: 3919745 bytes, checksum: 716e0ca6a5f49638e524df0464557d83 (MD5) Previous issue date: 1999
Resumo: O presente trabalho trata do estudo da produção de vitamina B12, consistindo das seguintes etapas: seleção do melhor microrganismo produtor; seleção da melhor fonte de substrato, e do meia de cultura, avaliação, modelagem e otimização, das variáveis experimentais e fermentação em reator de bancada, para a obtenção das condições de operação e parâmetros cinéticos que influenciam no rendimento de produção da vitamina. A primeira fase consistiu da seleção do melhor microrganismo produtor a ser utilizado, nos estudos posteriores. Partiu-se das seguintes culturas tidas como boas produtoras de B12: Propionibacterium jensenii DSM 20274, Propionibacterium freudenreichii ATCC 9614, Propionibacterium shermanii ATCC 62Q1, Pseudomonas sp. ATCC 13867 e mais três mutantes isolados. Aqui como nas duas próximas etapas, os ensaios, foram realizados em frascos agitados, com base nos resultados, obtidos, decidiu-se pela seleção do mutante Pseudomonas P3, que chegou a uma produção máxima de 3,86 mg B12/1. A escolha da melhor fonte de substrato e do meio de cultura com composição mais indicada ocorreu paralelamente à escolha do microrganismo. Foram testadas lactose e sacarose e mais três composições de meio: meio 1, meio 2, e meio 3. A sacarose e o meio 1, associados ao mutante selecionado, proporcionaram os melhores rendimentos de B12, produção de biomassa e consumo de substrato. As culturas de. Propionibacterium mostraram maior um maior consumo de lactose do que as Pseudomonas. Na terceira etapa, estudou-se a influência de sete variáveis experimentais, previamente pesquisadas e selecionadas, na produção de B12. Foram elas: idade do inoculo, tempo de fermentação, temperatura, pH, concentração de substrato, de 5,6 DMI e de cobalto. Até a etapa de otimização, foram efetuados um planejamento fracionário, dois planejamentos com composto central e um caminho de ascendência máxima. As variáveis com seus respectivos níveis otimizados, que mais influenciaram a resposta, foram: concentração de 5,6 DMI (98,8 mg/l), temperatura (34,6 °C) e pH (7,14). O planejamento experimental permitiu um aumento de quase. 100% na produção de vitamina, alcançando um máximo de 7,57 mg BI2/1. Os ensaios no fermentador de bancada objetivaram verificar a influência do tempo de adição de 5,6 DMI, KLa e controle de pH no rendimento da vitamina. Concluiu-se que o tempo, ótima de adição, do precursor e a nível de Kls mais, indicado, foram respectivamente, 48 h e 36,8 h-1. Por outro lado, percebeu-se que o controle do pH não melhorou, a produção de vitamina nem aumentou, a velocidade de crescimento do microrganismo
Abstract: The present deals with the study of the production of vitamin B12, consisting of the following stages: selection of the best producing microorganism, selection of the best substrate, source, and the more, suitable medium of culture; evaluation, modeling and optimization of the experimental variables and; fermentation in a bench-fermentor for the obtaining of the operation, conditions and. kinetic parameters that, influence, the yield of the vitamin. The first phase consisted of the selection of the best producer microorganism to be used during the work. The following strains were used: Propionibacterium freudenreichii AICC 9614, Propiombacleruan jensenii. DSM 20274, Propianibacterium shermanii ATCC 6207, Pseudomonas sp. ATCC 13867 and more three mutants isolated. Here as in o stages, the experiments were, conducted in shake-flasks Based on the obtained results, the mutant Pseudomonas P3 was selected, producing a maximum of 3.86 mg BJ2/L. The selection of the best, substrate source, and medium composition was done parallelly to the microorganism selection. Were tested sucrose, lactose and three compositions of medium: medium 1 medium 2 and medium 3. The sucrose and medium 1, associated to the mutant P. P3, provided the best yields of B12, biomass production and substrate consumption. The strains of Propionibacterium showed larger ability in the lactose degradation than Pseudomonas and its mutants. In the third stage it was studied the influence of seven experimental variables in the production of vitamin B12: age of inoculum, time of fermentation, temperature, pH, substrate concentration, 5,6 Dimethylbenzimidazole (DMT> concentration and cobalt concentration. Up to the optimization step were realized a fractional factorial design, a steepest ascent path and two central composite design The most significant parameters, with respective optimized levels, were: 5,6 DMI (98.8 mg/L), temperature (34.6 °C) and pH (7-14)-. The experimental design allowed an. increase of almost 100% in. the Vitamin production, reaching a maximum of 7.57 mg B12/L. The experiments in the bench-fermentor were done to verify, the influence of the time of addition of 5,6 DMI, Kla and pH control in the yield of vitamin B12. The better time of addition and level of KLa, were respectively 48 hr and 36.8 hr-1. The control of pH did not improve the vitamin production
Doutorado
Doutor em Engenharia de Alimentos
48
Zhang, An. "Metabolic Engineering and Process Development for Enhanced Propionic acid Production by Propionibacterium acidipropionici". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1230919153.
Pełny tekst źródła
49
Bergh, Drott Johanna. "The role of microorganisms in prostate cancer development". Doctoral thesis, Umeå universitet, Institutionen för klinisk mikrobiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-59987.
Pełny tekst źródłaStreszczenie:
Prostate cancer is the most common cancer among Swedish men, but the aetiology of this disease is largely unknown. There is evidence for a linkage between chronic inflammation and prostate cancer. The mechanisms causing prostate inflammation and how this could promote tumour development and progression are however largely unknown. Chronic inflammatory infiltrates are common findings in prostate tissue samples and infection is proposed to be one possible cause for this inflammation. Inflammatory cells release free radicals, cytokines, and growth factors that facilitate increased cell proliferation, DNA damage, mutations, and angiogenesis. However, the present literature on the presence of microbes in prostate tissue and their possible linkage to inflammation and cancer development is limited. Therefore, the aim of this thesis was to investigate if microorganisms are present in prostate tissue and to evaluate their role in inducing prostatitis and prostate epithelial neoplasia. The presence of microorganisms (virus, bacteria and fungi) was studied in clinical prostate tissue samples to evaluate whether or not the occurrences of microorganisms were different in patients that later developed cancer compared with matched controls that did not. Viruses, bacteria and fungi were found in prostate tissues. Out of eight different viruses investigated, EBV and JC virus were detected, but there were no differences in occurrence in the case group compared to the control group. The fungus Candida albicans was present in a very small proportion of the prostate tissue samples. The predominant bacterium was Propionibacterium acnes and the second most prevalent was Escherichia coli. The presence of Propionibacterium acnes was associated with inflammation and subsequent prostate cancer development. Propionibacterium acnes was further evaluated for its capacity to induce an inflammatory response both in vitro and in vivo. Live Propionibacterium acnes induced a strong immune reaction in prostate epithelial cells in vitro with up-regulation of inflammatory genes and secretion of pro-inflammatory cytokines. Infection with Propionibacterium acnes in rat prostate resulted in a lobe specific inflammation with the most intense inflammation in the dorso-lateral prostate, lasting up to 3 months post-inoculation. Propionibacterium acnes inflammation was also associated with altered epithelial cell morphology, signs of DNA damage and increased cell proliferation. Taken together, this thesis shows that different viruses and bacteria can be found in prostate tissue. Propionibacterium acnes, the most abundant among the bacteria detected and more prevalent in the cancer than in the control group, exhibits strong prostatitis promoting properties both in vitro and in vivo. In addition, Propionibacterium acnes can induce some of the epithelial changes known to occur during prostate neoplasia formation. This thesis therefore suggests that Propionibacterium acnes induced chronic prostatitis could promote prostate cancer development. Further studies are needed to elucidate the molecular interplay linking Propionibacterium acnes induced inflammation and the formation of a pre-neoplastic state that could evolve into prostate cancer.
50
BOKOBZA, PHILIPPE. "Infections neuromeningees a p. Acnes : a propos de 13 cas dont 9 porteurs de derivations de liquide cephalo-rachidien : etude des concentrations minimales inhibitrices de 8 antibiotiques sur ces souches". Reims, 1991. http://www.theses.fr/1991REIMMO97.
Pełny tekst źródła