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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Techniques de culture pour l'étude du microbiote digestif anaérobie / Techniques of culture for the study of the anaerobic gut microbiota

Guilhot, Elodie 23 November 2017 (has links)
Les microorganismes anaérobies représentent la population majoritaire de notre tube digestif et ont un impact remarquable sur notre santé. Leur culture demeure à ce jour longue, fastidieuse et coûteuse et nombreux sont ceux qui restent incultivables. Or la culture est un outil indispensable pour l'étude du microbiote digestif. Ainsi, le laboratoire dans lequel ma thèse s’est déroulée a créé un nouveau concept de culture « Microbial Culturomics » qui a permis d’isoler 193 nouvelles espèces bactériennes anaérobies. Un travail sur l’utilisation des antioxydants pour permettre la culture aérobie des bactéries anaérobies a également été amorcé : une optimisation des techniques de culture prometteuse autour de laquelle mes travaux ont vu le jour. Notre premier projet a consisté à développer un dispositif de culture innovant permettant la culture des archaea méthanogènes en aérobiose et en absence de source externe de dihydrogène. Notre deuxième projet a consisté à élaborer un flacon d’hémoculture unique dans lequel la croissance de toutes les bactéries, aérobies et anaérobies, pouvaient être détectées. Notre troisième projet quant à lui repose sur la comparaison du mode de culture anaérobie et de celui en aérobie avec les antioxydants à travers l’exemple de trois souches bactériennes strictement anaérobies. L’utilisation des antioxydants pour faciliter la culture des microorganismes anaérobies a donc apporter des résultats très prometteurs qui pourrait être utilisés, après validation par des études multicentriques dans les laboratoires de microbiologie clinique et environnementaux. / Anaerobic microorganisms are characterized by their ability to grow and survive in the absence of oxygen. Indeed free oxygen molecules are not used for their metabolism and can be toxic to varying degrees, sometimes leading to cell death. Although it is known that these microorganisms are the predominant in our digestive microbiota and that they have a great impact on our health, their culture remain long, fastidious, costly, and in most cases impossible. Becteria culture is an indispensable tool for isolating strains, performing studies from living models, and identifying new ones. Thus, the laboratory in which my thesis tooks place created a new concept of culture "Microbial Culturomics" which made it possible to isolate 193 new anaerobic bacterial species. A work based on the use of antioxidants to enable the aerobic culture of anaerobic bacteria was also initiated: a promising optimization of the culture techniques from which my work was born. Our first project consisted in developing an innovative culture device allowing the cultivation of methanogenic archaea in aerobic and without an external source of dihydrogen. In our second project, we performed a single culture bottle in which the growth of all bacteria, aerobic and anaerobic, could be detected. Our third project was based on the comparison of anaerobic and aerobic culture with antioxidants through the example of three strictly anaerobic bacterial strains.Therefore the use of antioxidants enable to facilitate anaerobic bacteria cultivation. These results are very encouraging for clinical and environmental microbiology laboratories.
132

Treatment of softdrink industry wastewater using an integrated anaerobic/aerobic membrane bioreactor

Erdogan, Innocentia Gugulethu January 2014 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technologae: Chemical Engineering in the Faculty of Engineering at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014 / Most softdrink industries in developing countries are moving towards wastewater reuse or recycling. Water and wastewater reutilization, costs of treatment and disposal guidelines, remain the most critical factors for the development of sustainable water use for softdrink industries. Wastewater reuse or recycle has potential in the softdrink industry, depending on the wastewater characteristics’ concentration and volume. During this study, an integrated laboratory scale anaerobic/aerobic sidestream membrane bioreactor (MBR) system was used for treating softdrink industry wastewater (SDIW). The aim was to evaluate the system’s performance, and identify potential opportunities to recycle the water, and therefore reduce freshwater intake and minimise wastewater production. The objectives were to: evaluate: 1) treatment efficiencies for the individual stages; 2) biogas production in the anaerobic stage; and 3) the overall performance of the integrated system under different operating conditions. The SDIW used in this study was classified as medium to high strength wastewater with a total chemical oxygen demand (CODt) ranging between 2 242 and 11 717 mg/L and a biological oxygen demand (BOD) of up to 1 150 mg/L. The major pollutants in the SDIW were caustic soda; dissolved sugars, namely fructose (1 071 mg/L) and sucrose (6 900 mg/L); with the pH ranging between 6.1 and 12. The SDIW was characterized by total suspended solids (TSS) of 66 mg/L, as well as fats, oils and greases (FOG) of 40 mg/L. The maximum turbidity and colour was 65.3 NTU and 42 mg Pt/L, respectively. All the physiochemical properties and inorganic parameters were within the within the City of Cape Town’s (CCT’s) industrial wastewater quality discharge standards by-law (South Africa, 2006). Excluding the total dissolved solids (TDS) and electrical conductivity (EC) with maximum values were 1 050 mg/L and 1 483 μS/cm, respectively. Anaerobic pre-treatment of this SDIW was studied using a laboratory-scale expanded granular sludge bed (EGSB) reactor maintained at mesophilic temperature of between 35 to 37˚C. An organic loading rate (OLR), upflow velocity (Vup) and hydraulic retention time (HRT) of 10.9 kg COD/m3d, 0.85 m/h and ~11.8 h, respectively, resulting in COD treatment efficiencies of up to 93% CODt. An increase in nitrate (NO3-) in the EGSB product stream was an indication of an anaerobic ammonium (NH4+) oxidation (ANAMMOX) process. Anaerobic digestion (AD) of SDIW in the EGSB resulted in biogas production with methane (CH4), carbon dioxide (CO2), nitrogen (N2), and oxygen (O2), concentrations of up to 70%, 11%, 14.8%, and 4.1%, respectively. At the OLR and Vup of 10.9 kg COD/m3d and 0.85 m/h, respectively, the EGSB produced 16.7 L/d of biogas. The EGSB anaerobic pre-treatment resulted in stable treatment efficiencies for the removal of organic constituents, as well as biogas production without adding an external carbon source. The MBR post-treatment satisfactorily operated at a feed flowrate of up to 33.7 L/d, OLR of 2.3 and 3.1 kg COD/m3d for the anoxic and aerobic zones, respectively, and an HRT of approximately 0.41 h for both zones. The average CODt removal achieved was 86%. The dissolved oxygen (DO) concentration of 2.1 mg/L in the anoxic zone combined with an aeration rate and DO concentration of 11.8 L/min and 5.7 mg/L, in the aerobic zone resulted in NH4+; NO3-; and orthophosphate (PO43-), removal rates up to 90%; 55% and 39%, respectively. However, the MBR post-treatment did not decrease the orthophosphate concentration to within the SANS 241:2011 drinking water standards. The integrated EGSB-MBR treatment for SDIW was able to achieve an overall CODt removal efficiency of up to 94%. Although the MBR performance was successful the EC, TDS, PO43-, and colour concentrations in the ultrafiltration (UF) permeate did not meet the CCT’s industrial wastewater standards by-law (2006) as well as the SANS’ drinking water standards 241:2011 and required further treatment for reuse.
133

Bioprodução de 2,3-butanodiol eem meio mineral contendo glicerol derivado da indústria de biodiesel

Souza, Bruna Campos de 25 May 2018 (has links)
O 2,3-butanodiol (2,3-BDO) é um composto com potencial de uso em diferentes segmentos industriais, podendo ser obtido por síntese química tradicional ou via processos fermentativos a partir de diferentes fontes de carbono. Entre suas aplicações potenciais, destaca-se a utilização como precursor na indústria de polímeros, matéria-prima na produção de solventes, agente anticongelante, combustível líquido ou aditivo de combustíveis. A síntese de 2,3-BDO pela fermentação do glicerol subproduto da indústria de biodiesel por bactérias anaeróbias facultativas é particularmente atrativa, considerando-se a grande disponibilidade desta matéria-prima e a possibilidade de integração de processos e produtos no conceito de biorrefinaria. Entretanto, o uso do glicerol subproduto para este fim, deve ser ainda cuidadosamente avaliado, considerando a significativa quantidade de impurezas nele contidas. Neste trabalho, avaliou-se a utilização do glicerol subproduto em meio mineral, para o crescimento celular e produção de estereoisômeros de 2,3-BDO e acetoína por Klebsiella oxytoca ATCC 8724 e Enterobacter aerogenes ATCC 13048. Os resultados foram comparados com os alcançados om o uso de glicerol puro e glicose, em ensaios em regime descontínuo alimentado com concentração inicial de substrato (S0) de 80 g/L, em meio mineral padrão (PC), frequência dos agitadores de 700 rpm e fluxo específico de ar de 0,50 volumes de ar por volume de meio por minuto (vvm). Na sequência, foram realizados ensaios fermentativos com E. aerogenes com glicerol subproduto e diferentes meios de cultivo relatados na literatura, com S0 = 40 g/L, variação da frequência dos agitadores (650 a 750 rpm) e do fluxo específico de ar (0,50 a 0,87 vvm). Para a otimização do meio de cultivo, realizou-se um planejamento experimental do tipo Box-Behnken Design-3k, com a avaliação de três variáveis independentes - (NH4)2SO4, (NH4)2HPO4 e MgSO4.7H2O -, em três níveis. A avaliação cinética do cultivo de E. aerogenes no meio definido foi realizada em regime descontínuo em comparação ao uso do meio mineral padrão (PC). As metodologias analíticas utilizadas no decorrer da pesquisa foram validadas. Como resultados, nos cultivos com E. aerogenes em regime descontínuo alimentado, empregando-se glicerol puro e subproduto como substratos, rendimentos (ρ) da ordem de 82 e 84%, respectivamente, foram atingidos, sendo superiores ao obtido com glicose (71%). Nos ensaios conduzidos com diferentes formulações de meios de cultivos, a produção de biomassa foi favorecida na primeira etapa da fermentação com o uso do meio MD4, sendo cerca de 38% superior em relação ao meio mineral padrão (PC). Nos ensaios de otimização, E. aerogenes foi capaz de adaptar-se frente às diferentes concentrações dos sais presentes no meio contendo glicerol subproduto. Visando maximizar os resultados em termos de produção específica em relação à biomassa (YP/X), fator de conversão de substrato em produtos (YP/S) e concentração final de produtos (Pf), a partir dos resultados da otimização, sugere-se a utilização de um meio de cultivo definido contendo (g/L): glicerol, 80; (NH4)2SO4, 7,71; (NH4)2HPO4, 3,15; MgSO4.7H2O, 0,6; KOH, 0,45. Considerando o conjunto de características dos métodos cromatográficos e espectrofotométricos utilizados, ambos são adequados para aplicação nesta pesquisa, fornecendo resultados confiáveis das fermentações. De forma geral, os resultados alcançados indicam a aplicabilidade do glicerol subproduto como substrato para a produção fermentativa de 2,3-BDO e acetoína pelas bactérias anaeróbias facultativas Klebsiella oxytoca ATCC 8724 e Enterobacter aerogenes ATCC 13048. Além disso, também foi demonstrado que a produção de 2,3-BDO pode ser conduzida com E. aerogenes a partir de glicerol subproduto, empregando-se meios simplificados em comparação ao padrão descrito na literatura, significando um ganho econômico para esta fermentação. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES / 2,3-butanediol (2,3-BDO) is a compound with potential to be used in different industrial segments, that can be obtained by traditional chemical synthesis or via fermentative processes from different carbon sources. Among its potential applications, it is included the use as chemical building blocks in polymer industries, raw material for the production of solvents, antifreeze agent, liquid fuel or fuel additive. The synthesis of 2,3-BDO by the fermentation of glycerol by-product of the biodiesel industry by facultative anaerobic bacteria is particularly attractive considering the high availability of this substrate and the possibility of integrating processes and products into the concept of biorefinery. However, the use of the by-product glycerol for this purpose is still to be carefully assessed considering the significant amount of impurities it contains. In this work, the use of by-product glycerol in mineral medium for the cell growth and the production of stereoisomers of 2,3-BDO and acetoin by Klebsiella oxytoca ATCC 8724 and Enterobacter aerogenes ATCC 13048 was evaluated. The results were compared with those obtained with the use of pure glycerol and glucose, in fed-batch cultivations with initial substrate concentration (S0) of 80 g.L-1, standard mineral medium (PC), impeller speed of 700 rpm, and air flow rate of 0.50 volumes of air per volume of medium per minute (vvm). In order, cultivations with E. aerogenes with by-product glycerol and different culture media reported in the literature, with S0 = 40 g.L-1, variation of the impeller speed (650 to 750 rpm) and the specific air flow rate (0.50 to 0.87 vvm), were carried out. For the optimization of the culture medium, an experimental Box-Behnken Design -3k was performed, with the evaluation of three independent variables – (NH4)2SO4, (NH4)2HPO4 and MgSO4.7H2O –, at three levels. The kinetic evaluation of the cultivation of E. aerogenes in the defined medium was performed in batch fermentations in comparison to the use of the standard mineral medium (PC). The analytical methodologies used during the research were validated. As results, in fed-batch cultivations with E. aerogenes, using pure glycerol and by-product as substrates, yields (ρ) of the order of 82 and 84%, respectively, were reached, higher than that obtained with glucose (71%). In the trials conducted with different formulations of culture media, biomass production was favored in the first fermentation stage using the MD4 medium, about 38% higher than the standard mineral medium (PC). In the optimization experiments, E. aerogenes was able to adapt to the different concentrations of the salts present in the medium containing by-product glycerol. In order to maximize the results in terms of specific production factorin relation to biomass (YP/X), product from substrate conversion factor (YP/S) and final product concentration (Pf), from the optimization results, it is suggested the use of a defined medium containing (g.L-1): glycerol, 80; (NH4)2SO4, 7.71; (NH4)2HPO4, 3.15; MgSO4.7H2O, 0.6, KOH, 0.45. Considering the set of characteristics of the chromatographic and spectrophotometric methods used, both are suitable for application in this research, providing reliable results of the fermentations. In general, the results indicate the applicability of by-product glycerol as a substrate for the fermentative production of 2,3-BDO and acetoin by the facultative anaerobic bacteria Klebsiella oxytoca ATCC 8724 and Enterobacter aerogenes ATCC 13048. In addition, it has also been demonstrated that the production of 2,3-BDO can be conducted by E. aerogenes from by-product glycerol, using simplified media in comparison to the standard one described in the literature, which would positively reflect in the costs for this fermentation.
134

Relationship between the presence of periodontal pathogens and plasma biomarkers in development of periodontal disease in children with type I diabetes mellitus = Relação entre a presença de periodontopatógenos e os níveis de biomarcadores plasmáticos no desenvolvimento da doença periodontal em crianças portadoras de diabetes melito tipo I / Relação entre a presença de periodontopatógenos e os níveis de biomarcadores plasmáticos no desenvolvimento da doença periodontal em crianças portadoras de diabetes melito tipo I

Dib João, Mariana Ferreira, 1987- 23 August 2018 (has links)
Orientadores: Cristiane Duque, Renata de Oliveira Mattos Graner / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-23T19:41:09Z (GMT). No. of bitstreams: 1 DibJoao_MarianaFerreira_M.pdf: 1014789 bytes, checksum: 02391fe3292ee31afa12160829713a12 (MD5) Previous issue date: 2013 / Resumo: A doença periodontal compreende um grupo de infecções inflamatórias que afeta os tecidos periodontais, podendo ser desencadeada por múltiplos fatores locais e sistêmicos. Indivíduos de todas as faixas etárias são susceptíveis ao desenvolvimento dessa doença e a gengivite, condição reversível limitada aos tecidos gengivais, é comumente vista em crianças e no início do período da adolescência. A presença de uma microbiota patogênica específica é um fator essencial para o desenvolvimento da doença periodontal (DP). Doenças sistêmicas tais como diabetes melito, podem contribuir para o desenvolvimento da doença, principalmente devido à resposta exacerbada do sistema imunológico e alterações em parâmetros fisiológicos que contribuem para a agressão tecidual. O objetivo deste estudo foi comparar os aspectos clínico, microbiológico e imunológico de crianças portadoras de diabetes melito tipo I (DM) com crianças não diabéticas (NDM). Vinte e quatro pacientes diabéticos e vinte e sete normoglicêmicos foram avaliados. As condições bucais foram avaliadas através dos índices de placa, gengival e profundidade de sondagem e o perfil de saúde geral dos pacientes foi avaliado através dos níveis de glicemia, HbA1c (hemoglobina glicosilada), triglicerídeos (TRG), colesterol total (CT), HDL, LDL, VLDL e lipídeos totais (LT), a partir de amostras sanguíneas. O método do PCR foi utilizado para identificação das seguintes bactérias: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td) (complexo vermelho), Prevotella intermedia (Pi) e Prevotella nigrescens (Pn), .Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr) (complexo laranja), Capnocytophaga sputigena (Cs), Capnocytophaga ochracea (Co), Eikenella corrodens (Ec) (complexo verde) em amostras do sulco gengival de dentes decíduos e permanentes. A avaliação imunológica incluiu a detecção dos níveis dos biomarcadores inflamatórios IL- 1?, TNF-? e IL-6 através de ensaios de ELISA. Os dados foram submetidos à análise estatística considerando p? 0,05. Os resultados mostraram que a condição periodontal de pacientes diabéticos e não diabéticos foi similar. Quando considerados pacientes com gengivite (IG ? 2), todos os índices lipídicos avaliados foram maiores no grupo dos diabéticos, com diferença estatística para HDL, TRG e LT. A prevalência do "complexo verde", principalmente Cs e Co foi maior nos sítios periodontais de crianças diabéticas. Bactérias do "complexo vermelho" foram detectadas em poucos sítios dos grupos DM e NDM. Fn e Cr, do "complexo laranja", foram frequentemente encontrados em ambos os grupos. Níveis dos biomarcadores IL-1-?, TNF-? e IL-6 foram similares no soro de DM e NDM. Houve correlação positiva entre as variáveis lipídicas e imunológicas avaliadas somente para o grupo diabético. Conclui-se que os perfis periodontal, microbiológico e imunológico avaliados neste estudo foram similares entre as crianças diabéticas e não diabéticas. Os parâmetros glicêmicos e lipídicos foram maiores nos pacientes diabéticos, mas mantiveram-se dentro da normalidade, demonstrando que controle metabólico é essencial para a manutenção da saúde periodontal / Abstract: Periodontal disease (PD) comprises a group of inflammatory infections that affects the periodontal tissues and may be triggered by multiple local and systemic factors. Individuals of all age groups are susceptible to develop this disease and gingivitis, reversible condition limited to the gingival tissues, is commonly seen in children and in the early adolescence period. The presence of a specific pathogenic microbiota is an essential factor to PD development. Systemic diseases, such as diabetes mellitus, can increase the development and progression of the disease, mainly due to exacerbated immunological response and changes in physiological parameters that contribute to tissue injury. The aim of this study was to compare clinical, microbiological and immunological profiles of type 1 diabetes mellitus children (DM) to non-diabetic control group (NDM). A total of twenty four DM children and twenty seven NDM controls were evaluated. Periodontal status was assessed using plaque index, gingival index and probing depth and general health status were determined using glycemic levels, HBA1c (glycosylated haemoglobin), HDL, LDL, triglycerides (TRG), total cholesterol (TC), VLDL and total lipids (TL), from blood samples. Polymerase chain reaction (PCR) was used for identification of the following bacteria: Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Capnocytophaga sputigena (Cs), Capnocytophaga ochracea (Co), Eikenella corrodens (Ec), Fusobacterium nucleatum (Fn), Tannerella forsythia (Tf), Treponema denticola (Td), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi) e Prevotella nigrescens (Pn) from gingival crevicular fluid of deciduous and permanent teeth. Immunological evaluation was determined by means of detection of inflammatory biomarkers -1?, TNF-? and IL-6 using ELISA assays. Data were submitted to statistical analysis, considering p? 0.05. The results showed that periodontal status of diabetic and non-diabetic patients was similar. Considering patients with gingivitis (GI ? 2), all lipid parameters evaluated were highest in DM group, however, statistical difference was observed only for HDL, TRG and TL. The prevalence of "green complex", mainly Cs and Co, was definitely more prevalent in periodontal sites of DM children. Bacteria from "red complex" were detected in few sites of DM and NDM groups. From the "orange complex", Fn and Cr were frequently found in both groups. Similar levels of the serum biomarkers, IL-1-?, TNF-? and IL-6, were detected in the serum of DM and NDM children. In conclusion, clinical, microbiological and immunological profiles evaluated in this study were similar between diabetic and nondiabetic children. Glycemic and lipid parameters were higher in diabetic patients, but remained within normal values, demonstrating that metabolic control is essential for maintaining periodontal health / Mestrado / Microbiologia e Imunologia / Mestra em Biologia Buco-Dental
135

Integrated anaerobic/aerobic bioprocess environments and the biodegradation of complex hydrocarbon wastes

Ehlers, George A C January 2004 (has links)
An investigation of the biodegradation of complex hydrocarbon wastes, with emphasis on chlorinated aromatic compounds, in an anaerobic/aerobic bioprocess environment was made. A reactor configuration was developed consisting of linked anaerobic and aerobic reactors which served as the model for a proposed bioremediation strategy targeting subterranean soil/sediment/aquifer chlorinated phenol-contaminated environments. Here oxygen is frequently limited and sulphate is readily available, as occurs especially in marine sediment and intertidal habitats. In the anaerobic system the successful transformation and mobilization of the model contaminant, 2,4,6-trichlorophenol, was shown to rely on reductive dechlorination by a sulphate-reducing dependent dechlororespiring co-culture. This was followed in the aerobic system by degradation of the pollutant and its metabolites, 2,4-dichlorophenol, 4-chlorophenol and phenol, by immobilized white-rot fungi.The strategy was initially investigated separately in laboratory bench- and intermediate scale reactors whereafter reactors were linked to simulate the integrated biodegradation strategy. The application of the fungal reactor to treat an actual waste stream by degrading complex mixtures of hydrocarbons in a waste oil recycling effluent was also investigated. The mineralization of phenol and 2,4,6-TCP by immobilized fungal cultures was studied in pinewood chip and foam glass bead-packed trickling reactors. The reactors were operated in sequencing batch format. Removal efficiency increased over time and elevated influent phenol and TCP (800 and 85 mg.L⁻¹) concentrations were degraded by > 98 % in 24 – 30 h batch cycles. Comparable performance between the packing materials was shown. Uptake by the packing was negligible and stripping of compounds induced by aeration had a minimal effect on biodegradation efficiency. Reactor performances are discussed in relation to sequencing batch operation and nutrient requirements necessary to sustain fungal activity in inert vs. organic material packed systems. It was shown that a co-culture consisting of sulphate-reducing and dechlororespiring bacteria established in fed-batch and soil flasks, as well as pine chip-packed fluidized bed reactors. Results showed reductive dechlorination of 2,4,6-TCP to be in strict dependence on the activity of the sulphate-reducing population, sulphate and lactate concentrations. Transformation to 2,4-DCP, 4-CP and phenol was enhanced in sulphate deficient conditions. Dechlororespiring activity was found to be dependent on the fermentative activity of sulphate-reducing bacteria, and the culture was also shown to mobilize and dechlorinate TCP in soils contaminated with the pollutant. Linking the systems achieved degradation of the compound by > 99 % through fungal mineralization of metabolites produced in the dechlororespiring stage of the system. pH correction to the anaerobic reactor was found to be necessary since acidic effluent from the fungal reactor inhibited sulphate reduction and dechlorination. The fungal reactor system was evaluated at intermediate-scale using a complex waste oil recycling effluent. Substantial COD reduction (> 96 % in 48 h batch cycles) and removal of specific effluent hydrocarbon components was shown in diluted, undiluted (COD > 37 g.L⁻¹) and 2,4,6-TCP-spiked effluents. Industrial application of the fungal reactor was evaluated in a 14 m³ pilot plant operated on-site at a waste oil processing plant.
136

Enzymology of activated sewage sludge during anaerobic treatment of wastewaters : identification, characterisation, isolation and partial purification of proteases

Tshivhunge, Azwiedziswi Sylvia January 2001 (has links)
During anaerobic digestion bacteria inside the digester require a carbon source for their growth and metabolism, sewage sludge was used as a carbon source in this study. The COD content was used to measure the disappearance of the substrate. COD content was reduced by 48.3% and 49% in the methanogenic and sulphidogenic bioreactors, respectively, while sulphate concentration was reduced by 40%, producing 70mg/L of hydrogen sulphide as the end product over the first 5-7 days. Sulphate (which is used as a terminal electron acceptor of sulphur reducing bacteria) has little or no effect on the sulphidogenic and methanogenic proteases. Sulphite and sulphide (the intermediate and end product of sulphate reduction) increased protease activity by 20% and 40%-80%, respectively. Maximum protease activity occurred on day 21 in the methanogenic reactor and on day 9 in the sulphidogenic reactor. The absorbance, which indicates the level of amino acid increased to 2 and 9 for methanogenic and sulphidogenic bioreactors, respectively. Proteases that were active during anaerobic digestion were associated with the pellet (organic particulate matter) of the sewage. These enzymes have an optimum activity at pH 10 and at temperature of 50°C. The proteases that were active at pH 5 and 7, had optimum temperatures at 30°C and 60°C, respectively. Due to their association with organic particulate matter, these enzymes were stable at their optimum temperatures for at least five hours at their respective pH. Inhibition by PMSF, TPCK and 1.10-phenanthroline suggested that proteases inside the anaerobic digester are a mixture of cysteine, serine and metalloproteases. At pH 5, however, EDTA appeared to enhance protease activity by 368% (three-fold). Acetic acid decreased protease activity by 21%, while both propionic and butyric acid at 200 mg/L cause total inhibition of protease activity while these acids at higher pH (where they exist as their corresponding salts) exerted little effect. Copper, iron and zinc inhibited protease activity by 85% at pH 5 with concentrations ranging between 200 and 600 mg/L. On the other hand, nickel, showed an increase in protease activity of nearly 250%. At pH 7 and 10, copper had no effect on protease activity while iron, nickel and zinc inhibited these enzymes by 20-40%. Proteases at pH 7 were extracted from the pellet by sonication, releasing 50% of the total enzymes into the solution. The enzymes were precipitated by ammonium sulphate precipitation, and further purified by ion exchange chromatography and gel filtration. Ion exchange chromatography revealed that most of the enzymes that hydrolyse proteins are negatively charged while gel filtration showed that their molecular weight is approximately 500 kDa.
137

Caractérisation du microbiote des flores vaginales normales et de vaginose bactérienne / Characterization of vaginal microbiota of normal and bacterial vaginosis floras

Diop, Khoudia 23 November 2018 (has links)
Grâce aux avancées de la technologie et nouvelles stratégies OMICS, de nombreuses études se sont intéressées au microbiote vaginal ces dernières années. Elles ont révélé l'impact de ce dernier sur la santé de la femme. En effet, un déséquilibre de la flore vaginale la rend vulnérable, la prédisposant à la vaginose bactérienne ainsi qu’à des complications gynéco-obstétricales sévères. La pathogénèse de la vaginose reste encore méconnue et le traitement classique par antibiothérapie échoue dans plus de 50% des cas. En analysant 50 prélèvements vaginaux provenant de patientes atteintes de vaginose et de femmes saines vivant en France et au Sénégal, nous avons constaté une plus grande diversité bactérienne chez les patientes par rapport aux témoins avec l'augmentation d'espèces telles que Gardnerella vaginalis, Atopobium vaginae ainsi que les procaryotes sensibles à l'oxygène, y compris les Cocci anaérobies à Gram-positif et les Prevotella. Les femmes saines renfermaient plus d’espèces de Lactobacillaceae et de Proteobacteria dans leurs flores. La combinaison de la métagénomique et la culturomique a permis d’identifier un complexe de 11 espèces/genres bactériens associés à la vaginose. L’utilisation de la culturomique a permis d’accroître le répertoire des bactéries humaines avec l’isolement de 27 nouvelles espèces. Le faible taux de recouvrement entre les données de métagénomique et celles de culturomique montre la nécessité de persévérer dans l’isolement des bactéries par culturomique. L’obtention d'isolats permettra d'explorer in vitro les compétitions entre les bactéries et pourrait servir également de matière première pour développer un traitement par bactériothérapie / Over the last decades, thanks to the technologic progresses including advanced molecular techniques and new OMICS strategies, many studies have focused on the vaginal microbiota. Thus, revealing the impact of the vaginal flora on women health. Indeed, the disruption of the vaginal bacterial community makes it prone to bacterial vaginosis and severe obstetrical and gynecological disorders. The pathogenesis of bacterial vaginosis is still unknown, and relapses are very frequent. Conventional treatment with antibiotic therapy fails in more than 50% of cases. The analysis of 50 vaginal samples from bacterial vaginosis patients and healthy women living in France and Senegal, showed a higher bacterial diversity in patients compared to controls with the increase of species such as Gardnerella vaginalis, Atopobium vaginae as well as oxygen-sensitive prokaryotes including Gram-positive anaerobic cocci, and Prevotella spp. Healthy women harbored more Lactobacillaceae species and Proteobacteria in their microbiota. The combination of metagenomics and culturomics has allowed the identification of a complex of 11 bacterial species/genera associated with bacterial vaginosis. The use of the culturomics approach has extended the repertoire of human-associated bacteria, with the isolation of 27 new bacterial species. The low range overlap between metagenomic and culturomics data indicates the need to continue the isolation of bacteria by culturomics. Obtaining isolates will make it possible to explore in vitro the competitions between the bacteria but can also be used as primary material for the development new treatments by bacteriotherapy
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Atividade antimicrobiana, anti-inflamatória, citotoxicidade e genotoxicidade do extrato glicólico de Stryphnodendron barbatiman (Vell.) Mart. (Barbatimão) /

Sper, Fabia Lugli. January 2018 (has links)
Orientador: Luciane Dias de Oliveira / Banca: Jônatas Rafael de Oliveira / Banca: Luana Marotta Reis de Vasconcellos / Resumo: Stryphnodendron barbatiman (Vell.) Mart (barbatimão) tem sido utilizado popularmente como anti-inflamatório e antimicrobiano. Este estudo se propôs a realizar a análise fitoquímica do extrato de S. barbatiman (Vell.) Mart. (barbatimão) e verificar in vitro algumas de suas atividades biológicas, como: antimicrobiana, sobre culturas planctônicas e biofilmes de Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, e Parvimonas micra; citotoxicidade e genotoxicidade em macrófagos murinos (RAW 264.7), fibroblastos murinos (L929) e queratinócitos humanos (HACAT); e ação anti-inflamatória sobre RAW 264.7 estimuladas por lipopolissacarídeo (LPS) de Escherichia coli. A atividade antimicrobiana sobre culturas planctônicas foi avaliada pelo método de microdiluição em caldo. Após, as concentrações efetivas foram avaliadas sobre biofilmes monomicrobianos. A análise de citotoxicidade foi verificada pelo teste de redução do brometo de 3(4,5-dimetiltiazol-2-yl)2,5-difeniltetrazólio (MTT) e a de genotoxicidade pelo teste de micronúcleos. A atividade anti-inflamatória foi analisada quantificando os níveis de citocinas pró-inflamatórias (TNF-α, IL-1β, IL-6 e IL-17) e anti-inflamatória (IL-10), por enzyme-linked immunosorbent assay (ELISA). Os dados foram analisados por ANOVA e Teste de Tukey, ou Kruskal-Wallis e teste de Dunns, com nível de significância de 5% (P≤0,05). O extrato foi eficaz sobre os biofilmes, redução entre 54 e 100%. O extrato não foi citotóxico para R... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Anti-inflammatory and antimicrobial are popular uses of Stryphnodendron adstringens (Mart.) Coville (barbatimão). This study proposed to perform the phytochemical analysis of S. barbatiman (Vell.) Mart. (barbatimão) extract and to verify in vitro some of its biological activities as antimicrobial on planktonic cultures and biofilms of Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, and Parvimonas micra; cytotoxicity and genotoxicity on human keratinocytes (HACAT), murine macrophages (RAW 264.7) and fibroblasts (L929), and anti-inflammatory action on RAW 264.7. The antimicrobial activity on planktonic cultures was evaluated by broth microdilution. Afterwards, the effective concentrations were evaluated on mono microbial biofilms. The cytotoxicity analysis was verified by the MTT test and the genotoxicity by the micronucleus test. Anti-inflammatory activity was evaluated in RAW 264.7 stimulated by lipopolysaccharide (LPS) of Escherichia coli and treated with the extract, quantifying the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-17) and anti-inflammatory (IL-10), by enzyme-linked immunosorbent assay (ELISA). The data that presented normal distribution were analyzed by ANOVA and Tukey's test, and those that were not, were analyzed by Kruskal-Wallis and Dunns test, with a significance level of 5% (p≤0.05). Barbatimão extract was effective on biofilms, reduction between 54 and 100%. The extract was not cytotoxic to RAW 264.7 and ... (Complete abstract click electronic access below) / Mestre
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Partial purification and characterization of F₄₂₀-dependent NADP reductase from Methanobrevibacter smithii strain DE1

Sheridan, Scott D. 01 January 1985 (has links)
The F420-dependent NADP reductase of Methanobrevibacter smithii has been partially purified employing a combination of affinity chromatography with Blue Sepharose (Cl-6B) and molecular sieve chromatography with Sephacryl S-200, The enzyme, which requires reduced F420 as an electron donor, has been purified over 145 fold with a recovery of 6%. A molecular weight of 120,00 for the native enzyme was determined by Sephacryl S-200 chromatography. A subunit molecular weight of 28,200 was determined by SDS-PAGE, indicating that the native enzyme is a tetramer. The optimal temperature for enzymatic activity was found to be 45°C, with a pH optimum of 7.5. The NADP reductase had an apparent Km of 42 uM for reduced F420, and an apparent Km of 4l uM for NADP. The enzyme was stable in 0.05 M sodium phosphate buffer (plus 10 mM cysteine) at pH 7.0, when gassed with nitrogen or hydrogen and stored at 4°C.
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Anaerobic Degradation of Polycyclic Aromatic Hydrocarbons at a Creosote-Contaminated Superfund Site and the Significance of Increased Methane Production in an Organophilic Clay Sediment Cap

Smith, Kiara L. 01 January 2010 (has links)
The overall goal of this work was to investigate microbial activity leading to the anaerobic degradation of polycyclic aromatic hydrocarbons and an organophilic clay sediment cap used at a creosote-contaminated Superfund site. To determine whether or not PAHs were being degraded under anaerobic conditions in situ, groundwater and sediment porewater samples were analyzed for metabolic biomarkers, or metabolites, formed in the anaerobic degradation of naphthalene (a low-molecular weight PAH). In addition, a groundwater push-pull method was developed to evaluate whether the transformation of deuterated naphthalene to a deuterated metabolite could be monitored in situ and if conservative rates of transformation can be defined using this method. Metabolites of anaerobic naphthalene degradation were detected in all samples that also contained significant levels of naphthalene. Anaerobic degradation of naphthalene appears to be widespread in the upland contaminated aquifer, as well as within the adjacent river sediments. A zero-order rate of transformation of naphthalene-D₈ to naphthoic acid-D₇was calculated as 31 nM·d-¹. This study is the first reported use of deuterated naphthalene to provide both conclusive evidence of the in situ production of breakdown metabolites and an in situ rate of transformation. Methane ebullition was observed in areas of the sediment cap footprint associated with organophilic clay that was used a reactive capping material to sequester mobile non-aqueous phase liquid (NAPL) at the site. Anaerobic slurry incubations were constructed using sediment core samples to quantify the contribution of the native sediment and the different layers of capping material (sand and organophilic clay) to the overall methane production. Substrate addition experiments using fresh, unused organophilic clay, as well as measured changes in total carbon in organophilic clay over time supported the hypothesis that microbes can use organophilic clay as a carbon source. Quantitative PCR (qPCR) directed at the mcrA gene enumerated methanogens in field samples and incubations of native sediment and capping materials. Denaturing gradient gel electrophoresis (DGGE) was also performed on DNA extracted from these samples to identify some of the predominant microorganisms within the sediment cap footprint. The organophilic clay incubations produced up to 1500 times more methane than the native sediment and sand cap incubations. The organophilic clay field sample contained the greatest number of methanogens and the native sediment contained the least. However, the native sediment incubations had greater numbers of methanogens compared to their respective field sample and comparable numbers to the organophilic clay incubation. An increase in methane production was observed with the addition of fresh, unused organophilic clay to the already active organophilic clay incubations indicating that organophilic clay stimulates methanogenesis. In addition, organophilic clay retrieved from the field lost about 10% of its total carbon over a 300-day incubation period suggesting that some component of organophilic clay may be converted to methane. DGGE results revealed that some of the predominant groups within the native sediment and sediment cap were Bacteriodetes, Firmicutes, Chloroflexi, and Deltaproteobacteria. An organism 98% similar to Syntrophus sp. was identified in the organophilic clay suggesting this organism may be working in concert with methanogens to convert the organic component of organophilic clay ultimately to methane. The capacity of organophilic clay to sequester organic contaminants will likely change over time as the organic component is removed from the clay. This, in turn, affects the use of this material as a long-term remedial strategy in reduced, contaminated environments.

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