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Obtenção e caracterização filogenética de consórcio bacteriano utilizado em reator anaeróbio em batelada aplicado à produção de hidrogênio; Collection and phylogenetic characterization of bacterial consortium used in batch anaerobic reactor applied to hydrogen production

Maintinguer, Sandra Imaculada
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/03/2009 PT
Relevância na Pesquisa
46.59%
O pré-tratamento a quente do inoculo associado ao controle do pH tem sido aplicado para selecionar bactérias produtoras de hidrogênio, como por exemplo, Clostridium sp. Nesse sentido, o objetivo desse trabalho foi obter consórcio de bactérias anaeróbias produtoras de hidrogênio a partir de inóculo proveniente de lodo granulado de reator UASB, usado no tratamento de dejetos de suinocultura. Para tanto, foi realizado tratamento a quente do inóculo e, posterior, enriquecimento com diluições seriais visando obter consórcio anaeróbio. Foram utilizados 20% (v/v) desse consórcio como inóculo nos ensaios de determinação de gás hidrogênio em reatores com diferentes concentrações de sacarose e xilose. Os reatores anaeróbios (2 L) foram alimentados com sacarose e xilose, separadamente, em triplicata, a 37 graus Celsius, pH 5,5 e headspace com 'HE' (100%) para as seguintes condições: (1) 630,0 mg sacarose/L; (2) 1184,0 mg sacarose/L; (3) 1816,0 mg sacarose/L, (4) 4128,0 mg sacarose/L, (5) 630,0 mg xilose/L; (6) 1341,0 mg xilose/L; (7) 1848,0 mg xilose/L e (8) 3588,0 mg xilose/L. A produção de 'H IND.2' foi verificada em todos os reatores anaeróbios e não houve geração de metano. Os rendimentos de substrato a 'H IND.2' para as condições (1)...

Papel como fonte alternativa para produção anaeróbia de hidrogênio; Paper as an alternative source for anaerobic production

Botta, Lívia Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/03/2012 PT
Relevância na Pesquisa
46.48%
O objetivo desse trabalho foi avaliar a produção de 'H IND.2' a partir da degradação de papel sulfite com a utilização de consórcio microbiano obtido do fluido ruminal, na presença e ausência da celulase. Para obtenção de consórcio de bactérias essencialmente produtoras de ' H IND.2', fluido de rúmen in natura, utilizado como inóculo, foi submetido a tratamento ácido (pH 3 por 24 h), e posteriormente enriquecido em meio de cultura Del Nery modificado em diluições seriais. Nos ensaios de produção de 'H IND.2' foi utilizado 10% (v/v) desse inóculo em reatores com diferentes concentrações de papel e celulase, e em reatores controle, nos quais não houve adição de celulase. Reator anaeróbio em batelada, em triplicata, com papel sulfite e meio Del Nery modificado, foi mantido a 37 ºC, pH inicial 7,0, com headspace preenchido com 'N IND.2' (100%) para os seguintes ensaios: (1) 0,5 g papel/L e 4 mL celulase/L; (2) 2,0 g papel/L e 15 mL celulase/ L; (3) 4,0 g papel/L e 30 mL celulase/L; (CT 1) 0,5 g papel/L; (CT 2) 2,0 g papel/L; (CT 3) 4,0 g papel/L. Os rendimentos de 'H IND.2' foram 42, 26,6 e 24 mmol' H IND.2'/g papel para os ensaios 1, 2 e 3, respectivamente. Não houve produção de 'H IND.2' nos reatores controle. O consumo de substrato...

Influência das substâncias húmicas na degradação do pesticida fipronil pela bactéria Burkholderia sp; Influence of the humic substances on the degradation of fipronil pesticide by the bacterium Burkholderia sp

Cappelini, Luciana Teresa Dias
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/06/2013 PT
Relevância na Pesquisa
46.37%
Devido à expansão da cultura canavieira, e aos altos custos dos insumos agrícolas, buscam-se novas formas de manejo do solo dentre elas o uso de substancias húmicas. Apesar disso os produtores aliam as técnicas alternativas as tradicionais como o uso do fipronil, um inseticida fenil - pirazólico muito utilizado na cultura de cana-de-açúcar. Apesar desta prática, pouco se sabe como ocorre à degradação biótica do fipronil, fipronil-sulfeto e fipronil sulfona, quando se utiliza as substâncias húmicas como forma de adubação. Por esse motivo o objetivo deste trabalho foi avaliar a degradação biológica do fipronil quando se utiliza substâncias húmicas. Para este estudo, empregou-se um método indireto de extração de DNA do solo, onde as bactérias foram cultivadas em meio contendo apenas água estéril e fipronil e posteriormente seu DNA foi extraído, fez-se a PCR utilizando o primer 27F/1100R e o produto da PCR foi clonado e sequenciado; as bactérias identificadas estão afiliadas aos gêneros: Clostridium sp, Bdellovibrio sp, Flavisolibacter sp, Burkholderia sp e Herbaspirillum sp. O gênero selecionado para o estudo foi afiliada a Burkholderia sp, devido a seu potencial de degradação citado na literatura. Adquiriu-se uma cepa pura de Burkholderia thailandensis Para determinação do fipronil e seus metabólitos...

Influência da relação C/N e C/P na produção de hidrogênio em reator anaeróbio de leito fluidificado; Influence of C/N and C/P ratio in hydrogen production in anaerobic fluidized bed reactor

Carosia, Mariana Fronja
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/08/2014 PT
Relevância na Pesquisa
46.43%
O objetivo deste estudo foi avaliar a influência da relação carbono/nitrogênio (C/N) e carbono/fósforo (C/P) na produção de hidrogênio (H2) em reator anaeróbio de leito fluidificado (RALF), contendo pneu triturado como material suporte para adesão microbiana. Foi utilizado substrato sintético contendo glicose (5.000 mg L-1) como fonte de carbono, com pH efluente de ±3,7. Foram operados quatro reatores com relações C/N=100 em R1, C/N=150 em R2, C/N=200 em R3 e C/N=250 em R4, sob condições mesofílicas. Os reatores foram operados por 18 meses e o experimento foi dividido em três fases: na 1º Fase a relação C/P foi mantida no valor de 300 e o tempo de detenção hidráulica (TDH) foi variado em 8, 6, 4, 2 e 1 h; na 2º Fase, o TDH foi mantido em 2 h e a relação C/P foi variada nos valores de 300, 500, 700, 900 e 1100; e na 3º Fase, o TDH foi mantido em 8 h e a relação C/P variada novamente nos valores de 300, 500, 700, 900 e 1100. Os maiores valores de produção volumétrica de hidrogênio (PVH) foram obtidos no R3 (C/N=200), TDH de 2 h e relação C/P=700 (0,70 L.h-1.L-1) e estiveram relacionados às rotas fermentativas de produção de etanol e ácido acético. Os maiores valores de rendimento de hidrogênio (YH) foram obtidos no TDH de 8 h...

Ocorrência de clostrídios patogênicos em solo de pastagem da micro-região de Jaboticabal, SP

Ragazani, Adriana Valim Ferreira
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: xi, 60 f. : il.
POR
Relevância na Pesquisa
46.66%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Microbiologia Agropecuária - FCAV; Entre as espécies de Clostridium de importância em patologia animal, destaca-se o Clostridium perfringens, o Clostridium botulinum, o Clostridium chauvoei. O objetivo desta pesquisa foi verificar a presença de bactérias anaeróbias esporuladas (Clostridium sp), assim como, identificar as espécies de Clostridium patogênicos para a saúde animal, principalmente de bovinos, no solo de pastagem da micro-região de Jaboticabal, SP. Foram coletadas 250 amostras de solo e realizadas contagens de bactérias esporuladas do gênero Clostridium e identificação das espécies patogênicas presentes. Os resultados permitiram demonstrar a contagem de UFC de Closrtidium sp com média em log 10 igual a 2,79, sendo que os valores mínimo e máximo obtido foram 2,15 e 3,68 respectivamente. Para caracterização e identificação, os resultados permitiram identificar a presença de bactérias anaeróbias esporuladas em 233 amostras (93,2%), entre estas 180 eram do gênero Clostridium...; The species of Clostridium of major importance to animal pathology are Clostridium perfringens, Clostridium botulinum, and C. chauvoei. Considering this...

Avaliação de estratégias para a construção de uma biblioteca genômica de Clostridium sp. e avaliação de atividade enzimática sobre substrato celulósico

Paulo, Filipe Araujo Teixeira
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Dissertação de Mestrado Formato: 78 p.| il., grafs., tabs.
POR
Relevância na Pesquisa
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2010; A massiva utilização de combustíveis fósseis contribui para o aumento da emissão de CO2 e consequente aumento do efeito estufa. Assim, o emprego de combustíveis renováveis, como o bioetanol, mostra-se como uma alternativa para a redução da emissão de gases aceleradores deste efeito. A hidrólise de substratos celulósicos pode ser realizada enzimaticamente, com o emprego das celulases (endoglicanases, xoglicanases e ß # glicosidases), um grupo de enzimas que atuam de modo sinérgico. O presente trabalho objetivou a avaliação de estratégias para construção de uma biblioteca genômica de Clostridium sp. e a avaliação da degradação de substratos celulósicos através da utilização de celulases recombinantes. Diferentes microrganismos celulolíticos foram avaliados quanto a capacidade de degradação de substrato específico para a enzima em questão. Tentou-se realizar a clonagem por meio de uma biblioteca genômica da bactéria Clostridium sp., onde foram testadas diferentes técnicas de fragmentação do DNA genômico deste microrganismo. Como não foi possível a clonagem...

Detection of Clostridium sp. and its Relation to Different Ages and Gastrointestinal Segments as Measured by Molecular Analysis of 16S rRNA Genes

Mirhosseini,Seyed Ziaeddin; Seidavi,Alireza; Shivazad,Mahmoud; Chamani,Mohammad; Sadeghi,Ali Asghar; Pourseify,Reza
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2010 EN
Relevância na Pesquisa
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The objective of this study was to establish a specific, sensitive and rapid PCR approach for the detection of Clostridium sp. at the genus level. Clostridium sp. in the duodenum, jejunum, ileum and cecum of broiler chickens were analyzed by 16S rRNA genes. The PCR detected the presence of Clostridium spp. in naturally contaminated intestinal samples. For the total gastrointestinal segments, 53.125, 65.625 and 59.375% samples were positive for naturally occurring Clostridium spp. at the ages 4, 14 and 30d, respectively. Analysis of the microbial contents indicated that Clostridium sp. was not consistently detected in all intestinal segments. These results can put in evidence the hypothesis that Clostridium spp. may be interfering in health and performance of chickens.

Identification and Characterization of a Bile Acid 7α-Dehydroxylation Operon in Clostridium sp. Strain TO-931, a Highly Active 7α-Dehydroxylating Strain Isolated from Human Feces

Wells, James E.; Hylemon, Phillip B.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2000 EN
Relevância na Pesquisa
46.65%
Clostridium sp. strain TO-931 can rapidly convert the primary bile acid cholic acid to a potentially toxic compound, deoxycholic acid. Mixed oligonucleotide probes were used to isolate a gene fragment encoding a putative bile acid transporter from Clostridium sp. strain TO-931. This DNA fragment had 60% nucleotide sequence identity to a known bile acid transporter gene from Eubacterium sp. strain VPI 12708, another bile acid-7α-dehydroxylating intestinal bacterium. The DNA (9.15 kb) surrounding the transporter gene was cloned from Clostridium sp. strain TO-931 and sequenced. Within this larger DNA fragment was a 7.9-kb region, containing six successive open reading frames (ORFs), that was encoded by a single 8.1-kb transcript, as determined by Northern blot analysis. The gene arrangement and DNA sequence of the Clostridium sp. strain TO-931 operon are similar to those of a Eubacterium sp. strain VPI 12708 bile acid-inducible operon containing nine ORFs. Several genes in the Eubacterium sp. strain VPI 12708 operon have been shown to encode products required for bile acid 7α-dehydroxylation. In Clostridium sp. strain TO-931, genes potentially encoding bile acid-coenzyme A (CoA) ligase, 3α-hydroxysteroid dehydrogenase, bile acid 7α-dehydratase...

Characteristics of a new cellulolytic Clostridium sp. isolated from pig intestinal tract.

Varel, V H; Pond, W G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1992 EN
Relevância na Pesquisa
46.3%
Gram-positive, spore-forming, motile, cellulolytic rods were isolated from 10(7) dilutions of pig fecal samples. The pigs had previously been fed pure cultures of the ruminal cellulolytic organism Clostridium longisporum. Isolates formed terminal to subterminal spores, and a fermentable carbohydrate was required for growth. Besides cellulose, the isolates utilized cellobiose, glycogen, maltose, and starch. However, glucose, fructose, sucrose, pectin, and xylose were not used as energy sources. Major fermentation products included formate and butyrate. The isolates did not digest proteins from gelatin or milk. Unlike C. longisporum, which has limited ability to degrade cell wall components from grasses (switchgrass, bromegrass, and ryegrass), the swine isolates were equally effective in degrading these components from both alfalfa and grasses. The extent of degradation was equal to or better than that observed with the predominant ruminal cellulolytic organisms. On the basis of morphology, motility, spore formation, fermentation products, and the ability to hydrolyze cellulose, the isolates are considered to be a new species of the genus Clostridium. It is unclear whether C. longisporum played a role in the establishment or occurrence of this newly described cellulolytic species. This is the first report of a cellulolytic Clostridium sp. isolated from the pig intestinal tract.

Utilization of PPi as an Energy Source by a Clostridium sp

Cruden, Diana L.; Durbin, W. E.; Markovetz, A. J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1983 EN
Relevância na Pesquisa
46.28%
The growth of an anaerobic, spore-forming rod we have isolated from the cockroach gut after enrichment on media containing PPi was stimulated by the presence of PPi. The doubling time decreased and cell yield increased proportionately to PPi concentrations of up to 0.35%. A similar stimulation of the growth of Desulfotomaculum sp. by PPi has been reported. The PPi-stimulated Clostridium sp. fermented a number of sugars with the production of hydrogen, acetate, and butyrate, with smaller amounts of ethanol and butanol being produced from some substrates. The fermentation products were not qualitatively changed by the presence of PPi, but significantly more hydrogen was produced. The organism contained several of the enzymes previously reported from Entamoeba sp. and Propionibacterium sp., in which PPi serves as a source of a high-energy bond in place of ATP. These include significant amounts of pyruvate-phosphate dikinase and phosphoenolpyruvate carboxytransphosphorylase. The activities of many of the catabolic enzymes of the organism, as well as of its phosphatases and pyrophosphatase, were similar whether it was grown in the presence or absence of PPi. The organism did not accumulate intracellular polyphosphate granules but stored large amounts of glycogen.

Specificity of bile salt sulfatase activity from Clostridium sp. strains S1.

Huijghebaert, S M; Eyssen, H J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1982 EN
Relevância na Pesquisa
46.52%
Clostridium sp. strain S1, an unnamed bile acid-desulfating strain from rat intestinal microflora (S.M. Huijghebaert, J. A. Mertens, and H. J. Eyssen, Appl. Environ. Microbiol. 43:185-192, 1982), was examined for its ability to desulfate different bile acid sulfates and steroid sulfates in growing cultures. Clostridium sp. strain S1 desulfated the 3 alpha-monosulfates of chenodeoxycholic, deoxycholic, and cholic acid, but not their 7 alpha- or 12 alpha-monosulfates. Among the 3-sulfates of the 5 alpha- and 5 beta-bile acids, only bile acid-3-sulfates with an equatorial sulfate group were desulfated. Hence, Clostridium sp. strain S1 desulfated the 3-sulfates of bile acids with a 3 alpha, 5 beta-, a 3 beta, 5 alpha- or a 3 beta, delta 5-structure. In contrast, the bile acid-3-sulfates with a 3 beta, 5 beta- or a 3 alpha, 5 alpha-structure were not desulfated. In addition, Clostridium sp. strain S1 did not hydrolyze the equatorial 3-sulfate esters of C19 and C21 steroids and cholesterol or the phenolic 3-sulfate esters of estrone and estradiol. 23-Nordeoxycholic acid with a C-23 carboxyl group was also not desulfated, in contrast to the 5 beta-bile acid 3 alpha-sulfates with a C-24 or C-26 carboxyl group. Therefore, the specificity of the sulfatase of Clostridium sp. strain S1 is related to the location of the sulfate group on the bile acid molecule...

Anaerobic Desulfonation of 4-Tolylsulfonate and 2-(4-Sulfophenyl) Butyrate by a Clostridium sp

Denger, K.; Kertesz, M. A.; Vock, E. H.; Schon, R.; Magli, A.; Cook, A. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1996 EN
Relevância na Pesquisa
46.37%
Alkyl- and arylsulfonates were tested as sole added sources of sulfur for the growth of enrichment cultures under strictly anaerobic denitrifying or fermentative conditions. Cultures that utilized taurine, ethylsulfonate, the dyestuffs orange II and acid red I, tolylsulfonate, 2-(4-sulfophenyl)butyrate (SPB), a dialkyltetralinesulfonate, and 1-(4-sulfophenyl)octane were readily obtained. We chose to work with the simple aromatic compounds and isolated a fermentative bacterium, strain EV4, which utilized SPB as the sole added source of sulfur in glucose-mineral medium. The organism was identified as a Clostridium sp. related to Clostridium beijerinckii. Clostridium sp. strain EV4 utilized seven of seven tested arylsulfonates quantitatively. The growth yield was about 3 kg of protein per mol of sulfur, whether sulfonate or sulfate was utilized. A major product specific to each sulfonate could be observed. Although no product was identified, the existence of anaerobic desulfonation has been established.

Isolation and Characterization of a New Clostridium sp. That Performs Effective Cellulosic Waste Digestion in a Thermophilic Methanogenic Bioreactor

Shiratori, Hatsumi; Ikeno, Hironori; Ayame, Shohei; Kataoka, Naoaki; Miya, Akiko; Hosono, Kuniaki; Beppu, Teruhiko; Ueda, Kenji
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2006 EN
Relevância na Pesquisa
46.3%
A methanogenic bioreactor that utilized wastepaper was developed and operated at 55°C. Microbial community structure analysis showed the presence of a group of clostridia that specifically occurred during the period of high fermentation efficiency. To isolate the effective cellulose digester, the sludge that exhibited high fermentation efficiency was inoculated into a synthetic medium that contained cellulose powder as the sole carbon source and was successively cultivated. A comprehensive 16S rRNA gene sequencing study revealed that the enriched culture contained various clostridia that had diverse phylogenetic positions. The microorganisms were further enriched by successive cultivation with filter paper as the substrate, as well as the bait carrier. A resultant isolate, strain EBR45 (= Clostridium sp. strain NBRC101661), was a new member of the order Clostridiales phylogenetically and physiologically related to Clostridium thermocellum and Clostridium straminisolvens. Specific PCR-based monitoring demonstrated that strain EBR45 specifically occurred during the high fermentation efficiency period in the original methanogenic sludge. Strain EBR45 effectively digested office paper in its pure cultivation system with a synthetic medium.

Resolution of Culture Clostridium bifermentans DPH-1 into Two Populations, a Clostridium sp. and Tetrachloroethene-Dechlorinating Desulfitobacterium hafniense Strain JH1▿

Fletcher, Kelly E.; Ritalahti, Kirsti M.; Pennell, Kurt D.; Takamizawa, Kazuhiro; Löffler, Frank E.
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.3%
Clostridium bifermentans strain DPH-1 reportedly dechlorinates tetrachloroethene (PCE) to cis-1,2-dichloroethene. Cultivation-based approaches resolved the DPH-1 culture into two populations: a nondechlorinating Clostridium sp. and PCE-dechlorinating Desulfitobacterium hafniense strain JH1. Strain JH1 carries pceA, encoding a PCE reductive dehalogenase, and shares other characteristics with Desulfitobacterium hafniense strain Y51.

The Selenoproteome of Clostridium sp. OhILAs: Characterization of Anaerobic Bacterial Selenoprotein Methionine Sulfoxide Reductase A

Kim, Hwa-Young; Zhang, Yan; Lee, Byung Cheon; Kim, Jae-Ryong; Gladyshev, Vadim N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/2009 EN
Relevância na Pesquisa
46.3%
Selenocysteine (Sec) is incorporated into proteins in response to UGA codons. This residue is frequently found at the catalytic sites of oxidoreductases. In the present study, we characterized the selenoproteome of an anaerobic bacterium, Clostridium sp. (also known as Alkaliphilus oremlandii) OhILA, and identified 13 selenoprotein genes, 5 of which have not been previously described. One of the detected selenoproteins was methionine sulfoxide reductase A (MsrA), an antioxidant enzyme that repairs oxidatively damaged methionines in a stereospecific manner. To date, little is known about MsrA from anaerobes. We characterized this selenoprotein MsrA which had a single Sec residue at the catalytic site but no cysteine (Cys) residues in the protein sequence. Its SECIS (Sec insertion sequence) element did not resemble those in Escherichia coli. Although with low translational efficiency, the expression of the Clostridium selenoprotein msrA gene in E. coli could be demonstrated by 75Se metabolic labeling, immunoblot analyses, and enzyme assays, indicating that its SECIS element was recognized by the E. coli Sec insertion machinery. We found that the Sec-containing MsrA exhibited at least a 20-fold higher activity than its Cys mutant form...

Simultaneous Fermentation of Glucose and Xylose to Butanol by Clostridium sp. Strain BOH3

Xin, Fengxue; Wu, Yi-Rui; He, Jianzhong
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2014 EN
Relevância na Pesquisa
46.45%
Cellulose and hemicellulose constitute the major components in sustainable feedstocks which could be used as substrates for biofuel generation. However, following hydrolysis to monomer sugars, the solventogenic Clostridium will preferentially consume glucose due to transcriptional repression of xylose utilization genes. This is one of the major barriers in optimizing lignocellulosic hydrolysates that produce butanol. Unlike studies on existing bacteria, this study demonstrates that newly reported Clostridium sp. strain BOH3 is capable of fermenting 60 g/liter of xylose to 14.9 g/liter butanol, which is similar to the 14.5 g/liter butanol produced from 60 g/liter of glucose. More importantly, strain BOH3 consumes glucose and xylose simultaneously, which is shown by its capability for generating 11.7 g/liter butanol from a horticultural waste cellulosic hydrolysate containing 39.8 g/liter glucose and 20.5 g/liter xylose, as well as producing 11.9 g/liter butanol from another horticultural waste hemicellulosic hydrolysate containing 58.3 g/liter xylose and 5.9 g/liter glucose. The high-xylose-utilization capability of strain BOH3 is attributed to its high xylose-isomerase (0.97 U/mg protein) and xylulokinase (1.16 U/mg protein) activities compared to the low-xylose-utilizing solventogenic strains...

Mel de abelhas nativas e africanizadas do estado de Alagoas : composição química, segurança microbiológica e atividade terapêutica.; Honey of beens native and africanized state of Alagoas State : chemical composition,security microbiological and activity therapy.

Duarte, Alysson Wagner Fernandes
Fonte: Universidade Federal de Alagoas; BR; Nutrição; Programa de Pós-Graduação em Nutrição; UFAL Publicador: Universidade Federal de Alagoas; BR; Nutrição; Programa de Pós-Graduação em Nutrição; UFAL
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.5%
The rational development of bees is one of the most promising agricultural activities, since it is essentially self-sustaining family and therefore helps to maintain and restore the environment, through their role in pollination, and guarantee income to the producer who employs his family on it. Honey is the main product of this activity, being generated by honey bees - native or Africanized. Its chemical composition is quite varied, depending mainly of floral, entomological and geographical origin. The purpose of this study was to evaluate the quality of honey from different entomologic sources of the State of Alagoas, in the dry season of 2008/09, by physico-chemical and microbiological criteria, and know their likely actions antioxidant and antimicrobial. Thus, 43 samples of honey (14 of Apis mellifera, 22 of M. scutellaris, 3 of M. quadrifasciata, 2 of M. subnitida e 2 of Plebeia sp) were collected from different municipalities of Alagoas. In relation to the physicochemical parameters, it were evaluated the content of reducing carbohydrates, total carbohydrates, sucrose apparent, moisture, electrical conductivity, pH, acidity, content of total protein, concentration of proline, diastase activity and hydroxymethylfurfural. Regarding to the antioxidant activity...

Prospec??o de bact?rias com potencial aplica??o na biorremedia??o de efluentes industriais contendo ars?nio

Guedes, Keicilane Aparecida
Fonte: Programa de P?s-Gradua??o em Engenharia Ambiental. PRO?GUA, Pr?-Reitoria de Pesquisa e P?s Gradua??o, Universidade Federal de Ouro Preto. Publicador: Programa de P?s-Gradua??o em Engenharia Ambiental. PRO?GUA, Pr?-Reitoria de Pesquisa e P?s Gradua??o, Universidade Federal de Ouro Preto.
Tipo: Dissertação
PT_BR
Relevância na Pesquisa
46.48%
O Ars?nio (As) est? naturalmente presente no ambiente terrestre associado a minerais sulfetados em rochas e sedimentos. Devido a oxida??es qu?micas e biol?gicas e principalmente a atividades ligadas ? minera??o e metalurgia, o As ? mobilizado de dep?sitos naturais tornando-se um importante contaminante ambiental. Em baix?ssimas concentra??es, esse metal?ide ? t?xico para diversos seres vivos. V?rios estudos t?m sido realizados a fim de remediar tais impactos imobilizando este elemento. Dentre as metodologias propostas podemos citar com destaque a utiliza??o de micro-organismos na remo??o de metais de efluentes e corpos d??gua contaminados. Bact?rias podem remover metais de uma solu??o por diferentes mecanismos, tais como aqueles que envolvem a acumula??o extracelular/precipita??o, a adsor??o i?nica na superf?cie celular ou complexa??o, e a acumula??o intracelular ou bioacumula??o. A remo??o de metais dos ambientes aqu?ticos tamb?m pode ocorrer pela a??o de metab?litos produzidos pelas bact?rias presentes como, por exemplo, pelo H2S produzido pelo grupo das Bact?rias Redutoras de Sulfato (BRS). Estes micro-organismos s?o peculiares por, atrav?s da redu??o qu?mica do sulfato, produzir sulfeto que, por sua vez, ? capaz de precipitar metais...

Identification and description of Clostridium sp. and metabolic activities in fermentative hydrogen production.

Wang, Xiaoyi
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
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46.41%
Hydrogen is an environmentally friendly and highly efficient energy source. Fermentative hydrogen production is an exciting R&D area that offers a means to produce hydrogen from a variety of renewable resources or even wastewaters. However, the development of fermentative hydrogen production processes has been hampered due to their low yield and relatively high costs. The aim of this thesis was to improve fundamental knowledge of hydrogen-producing bacteria, provide genetic information associated with the hydrogen evolution, and to optimise operating conditions to enhance hydrogen yield. Isolation and identification of hydrogen producing bacteria from activated sludge were conducted using 16S rRNA gene-directed PCR-denaturing gradient gel electrophoresis (DGGE), clone library and heterotrophic plate isolation. The results showed that Clostridium sp. were dominant and active hydrogen producers. For the first time, three hydrogen producers, which harboured the [FeFe] hydrogenase gene, were characterised by 16S rDNA sequencing, and further physiologically identified as Clostridium sp. (W1), Clostridium butyricum (W4) and Clostridium butyricum (W5). The structure of the putative [FeFe] hydrogenase gene cluster of C. butyricum W5 was also described. The changes in [FeFe] hydrogenase mRNA expression of C. butyricum W5 during fermentation were monitored. Statistical analysis showed that both the [FeFe] hydrogenase mRNA expression level and cell growth have positive relationships with hydrogen production. The newly isolated C. butyricum W5 demonstrated highly promising hydrogen fermentation performance and was therefore used as the working strain. Optimization of operating conditions in terms of carbon and nitrogen sources...

Transcriptional induction and expression of the endoglucanase celA gene from a ruminal Clostridium sp. ("C. longisporum").

Mittendorf, V; Thomson, J A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1995 EN
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Northern (RNA) blot analysis of RNA from Clostridium sp. revealed induction of transcription of the celA gene when barley beta-glucan was used as carbon source, while no celA mRNA was detected after growth on cellobiose. Western blots (immunoblots), prepared by using a rabbit antiserum raised against CelA protein purified from Escherichia coli, revealed the extracellular location of CelA in Clostridium sp. Despite the absence of detectable celA mRNA, significant quantities of CelA were detected in the culture supernatant during growth on cellobiose. This finding indicated a low constitutive expression of celA. A 6.7-fold increase in the total beta-glucanase specific activity in the extracellular fraction was observed during growth on beta-glucan. The transcriptional start site of celA was mapped by extension and was found to be the same in Clostridium sp. and in E. coli expressing the cloned celA gene. A consensus E. coli -10 promoter region (AATAAT), but not a -35 promoter region, could be identified. Two direct repeats (TATTGAATTTAT) separated by 15 nucleotides flank the region where the consensus -35 promoter regions would have been. The size of the celA mRNA transcript corresponded with the size of the open reading frame. A potential stem-loop structure was found 18 nucleotides downstream of the 3' stop codon...