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Pesquisa : D08.811.277.450.420.200 [Categoria DeCS]
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Martins, Meire Lelis Leal
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Id: biblio-849049
Autor: Oliveira, Luciana Ribeiro Coutinho; Barbosa, João Batista; Martins, Meire Lelis Leal; Martins, Marco Antônio.
Título: Extracellular production of avicelase by the thermophilic soil bacterium Bacillus sp SMIA-2 / Produção de avicelase extracelular pela bactéria termofílica Bacillus sp SMIA-2
Fonte: Acta sci., Biol. sci;36(2):215-222, abr.- jun. 2014. ilus, tab.
Idioma: en.
Resumo: Nowadays, the isolation of new bacterial strains that produce enzymes with novel properties is a subject of great relevance to the scientific community. This study, in order to search for producers of new cellulase strains, investigated the avicelase production by thermophilic Bacillus sp. strain SMIA-2. The best avicelase activity was observed in a culture medium containing 0.5% (w v-1) avicel and 0.5% (w v-1) corn steep liquor with initial pH 7.5- 8.0 incubated at 50 oC. When avicel was replaced in the medium by the treated sugarcane bagasse (0.5%, w v-1) the avicelase activity levels were not affected. Studies on the avicelase characterization revealed that the optimum pH of the enzyme was found to be 8.5 and the enzyme retained more than 80% of its activity after incubation at room temperature for 2h at pH 6.5-8.5. The optimum temperature of this enzyme was 70oC and the enzyme retained 67% of the original activity after 20 min. of heat treatment at 70oC. Avicelase was stimulated by Mn2+ and Co2+, whereas Hg2+ greatly inhibited the enzyme activity.

Atualmente, o isolamento de estirpes de bactérias que produzem enzimas com novas propriedades é um tema de grande relevância para a comunidade científica. Este trabalho, buscando por novas cepas produtoras de celulases, investigou a produção de avicelases pelo termofílico Bacillus sp. cepa SMIA-2. A melhor atividade da enzima foi obtida em uma cultura contendo 0,5% (p v-1) avicel e 0,5% (p v-1) água de maceração de milho com pH inicial de pH 7,5-8,0 e incubada a 50oC. A substituição da avicel no meio de cultura pelo bagaço de cana- de- açúcar tratado (0,5%, p v-1) não afetou os níveis de atividade da avicelase. Estudos sobre a caracterização da avicelase revelaram que o pH para atividade ótima da enzima foi 8,5 e que a mesma reteve mais de 80% de sua atividade após ser incubada à temperatura ambiente por 2 h a pH 6,5-8,5. A temperatura ótima da avicelase foi 70oC e a enzima reteve 67% da sua atividade original após 20 min. de incubação a 70oC. A avicelase foi estimulada pelos íons Mn2+ e Co2+, ao passo que Hg2+ inibiu a atividade da enzima.
Descritores: Bacillus
Celulases
Saccharum
Zea mays
Responsável: BR513.1 - Biblioteca Central


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Id: biblio-847977
Autor: Faheina Junior, Genilton da Silva; Amorim, Mariza Vieira da Fonseca Sabóia; Souza, Caroline Gondim de; Sousa, Diego Menezes de; Sousa, Kally Alves de; Pinto, Gustavo Adolfo Saavedra.
Título: Strategies to increase cellulase production with submerged fermentation using fungi isolated from the Brazilian biome / Estratégias para produção de celulases através de fermentação submersa utilizando fungos isolados do bioma brasileiro
Fonte: Acta sci., Biol. sci;37(1):15-22, jan.- mar. 2015. ilus.
Idioma: en.
Resumo: Studies on new microbial sources of cellulase and accurate assessment of the steps that increase cellulase production are essential strategies to reduce costs of various processes using such enzymes. This study aimed at the selection of cellulase-producing filamentous fungi, and at the research of parameters involving cellulase production by submerged fermentation. The first test consisted of selecting the best cellulase-producing microorganisms (FPase) in Erlenmeyer flasks containing 200 mL of specific growth medium. The next test was designed to further investigate the enzyme production in fermentation with four types of soluble sugars: glucose, lactose, sucrose and xylose. In bioreactor tests, three different inoculation strategies were analyzed. The best FPase activity was presented by the strain Trichoderma sp. CMIAT 041 (49.9 FPU L-1) and CMCase by the fungus Lasiodiplodia theobromae CMIAT 096 (350.0 U L-1). Sucrose proved to be the best option among the soluble sugars tested, with higher rates of FPase activity (49.9 FPU L-1) and CMCase (119.7 U L-1). The best inoculation strategy for the bioreactor was a spore suspension obtained from a semi-solid state fermentation of wheat bran for 72h.

Estudos sobre novas fontes microbianas e análises mais acuradas das etapas que compõem a produção de celulases são essenciais como estratégias para diminuir os custos gerados pelo uso de celulases nos processos de obtenção de açúcares fermentescíveis. O trabalho teve como objetivo a seleção de fungos filamentosos produtores de celulases e a investigação de parâmetros que envolvem a produção enzimática em fermentação submersa. O primeiro teste consistiu em selecionar os melhores fungos produtores de celulases totais em frascos Erlenmeyer contendo 200 mL de meio de cultura específico. O teste subsequente teve o intuito de investigar a produção enzimática com quatro tipos de açúcares solúveis: glicose, lactose, sacarose e xilose. Nos testes em biorreator foram analisados três diferentes estratégias de inoculação. Na etapa de seleção a melhor atividade de FPase foi apresentada por Trichoderma sp. CMIAT 041 (49,9 FPU L-1) e CMCase pelo fungo Lasiodiplodia theobromae CMIAT 096 (350,0 U L-1). O uso de sacarose mostrou-se ser a melhor opção dentre os açúcares solúveis testados, apresentando os maiores valores de atividade de FPase (49,9 FPU L-1) e CMCase (119,7 U L-1). A melhor estratégia de inoculação foi a suspensão de esporos obtidos a partir de fermentação em farelo de trigo, no tempo 72h.
Descritores: Brasil
Celulases
Ecossistema
Fermentação
Fungos
Responsável: BR513.1 - Biblioteca Central


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Id: biblio-840317
Autor: Bai, Xi; Yuan, Xianjun; Wen, Aiyou; Li, Junfeng; Bai, Yunfeng; Shao, Tao.
Título: Efficient expression and characterization of a cold-active endo-1, 4-β -glucanase from Citrobacter farmeri by co-expression of Myxococcus xanthus protein S
Fonte: Electron. j. biotechnol;19(6):79-83, Nov. 2016. ilus.
Idioma: en.
Projeto: Independent Innovation of Agricultural Sciences in Jiang Su Province; . National key Research and Development Program; . Network and Technology Served of Chinese Academy of Sciences Program (STS). Grassland agricultural system construction and industrialization demonstration of typical village (Jina village) in Tibet.
Resumo: Background: Cold-active endo-1, 4-β-glucanase (EglC) can decrease energy costs and prevent product denaturation in biotechnological processes. However, the nature EglC from C. farmeri A1 showed very low activity (800 U/L). In an attempt to increase its expression level, C. farmeri EglC was expressed in Escherichia coli as an N-terminal fusion to protein S (ProS) from Myxococcus xanthus. Results: A novel expression vector, pET(ProS-EglC), was successfully constructed for the expression of C. farmeri EglC in E. coli. SDS-PAGE showed that the recombinant protein (ProS-EglC) was approximately 60 kDa. The activity of ProS-EglC was 12,400 U/L, which was considerably higher than that of the nature EglC (800 U/L). ProS-EglC was active at pH 6.5-pH 8.0, with optimum activity at pH 7.0. The recombinant protein was stable at pH 3.5-pH 6.5 for 30 min. The optimal temperature for activity of ProS-EglC was 30°C-40°C. It showed greater than 50% of maximum activity even at 5°C, indicating that the ProS-EglC is a cold-active enzyme. Its activity was increased by Co2+ and Fe2+, but decreased by Cd2+, Zn2+, Li+, methanol, Triton-X-100, acetonitrile, Tween 80, and SDS. Conclusions: The ProS-EglC is promising in application of various biotechnological processes because of its cold-active characterizations. This study also suggests a useful strategy for the expression of foreign proteins in E. coli using a ProS tag.
Descritores: Celulases/metabolismo
Citrobacter/enzimologia
Escherichia coli/enzimologia
Myxococcus xanthus/enzimologia
-Temperatura Baixa
Vetores Genéticos
Proteínas Recombinantes
Responsável: CL1.1 - Biblioteca Central


  4 / 17 LILACS  
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Id: biblio-840314
Autor: Lin, Ling; Liu, Xiaozhou; Zhou, Yating; Guan, Linyan; Jiajia, He; Huang, Weiqian.
Título: A novel pH-stable, endoglucanase (JqCel5A) isolated from a salt-lake microorganism, Jonesia quinghaiensis
Fonte: Electron. j. biotechnol;19(6):56-62, Nov. 2016. ilus.
Idioma: en.
Projeto: Key Laboratory of Biotic Environment and Ecology Safety in Anhui Province. Anhui Provincial Natural Science Foundation.
Resumo: Background: Endoglucanase, one of three type cellulases, can randomly cleave internal p-1,4-linkages in cellulose polymers. Thus, it could be applied in agricultural and industrial processes. Results: A novel endoglucanase gene (JqCel5A) was cloned from Jonesia quinghaiensis and functionally expressed in Escherichia coli Rosetta (DE3). It contained 1722 bp and encoded a 573-residue polypeptide consisting of a catalytic domain of glycoside hydrolase family 5 (GH5) and a type 2 carbohydrate-binding module (CBM2), together with a predicted molecular mass of 61.79 kD. The purified JqCel5A displayed maximum activity at 55°C and pH 7.0, with 21.7 U/mg, 26.19 U/mg and 4.81 U/mg towards the substrate carboxymethyl cellulose, barley glucan and filter paper, respectively. Interestingly, JqCel5A exhibited high pH stability over a broad pH range of pH (3-11), and had good tolerance to a wide variety of deleterious chemicals including heavy metals and detergent. The catalytic mechanism of JqCel5A was also investigated by site mutagenesis and homology-modeling in this study. Conclusions: It was believed that these properties might make JqCel5A to be potentially used in the suitable industrial catalytic condition, which has a broad pH fluctuation and/or chemical disturbance.
Descritores: Actinomycetales/enzimologia
Celulases/química
Celulases/isolamento & purificação
-Celulases/genética
Concentração de Íons de Hidrogênio
Testes de Mutagenicidade
Temperatura Ambiente
Responsável: CL1.1 - Biblioteca Central


  5 / 17 LILACS  
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Id: lil-775128
Autor: Alrumman, Sulaiman A..
Título: Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid
Fonte: Braz. j. microbiol;47(1):110-119, Jan.-Mar. 2016. tab, graf.
Idioma: en.
Resumo: Abstract The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50 °C, respectively, after 24 h of incubation, with a yield of 31.56 mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24 h by using a two-step hydrolysis. Significant lactic acid production (27.8 mg/mL) was obtained by separate saccharification and fermentation after 72 h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate.
Descritores: Celulases/metabolismo
Celulose/metabolismo
Geobacillus stearothermophilus/enzimologia
Glucose/metabolismo
Resíduos Industriais
Ácido Láctico/metabolismo
Phoeniceae/metabolismo
-Álcalis
Biotransformação
Fermentação
Concentração de Íons de Hidrogênio
Phoeniceae/efeitos dos fármacos
Temperatura Ambiente
Responsável: BR1.1 - BIREME


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Id: lil-769645
Autor: Isaac, George Saad; Abu-Tahon, Medhat Ahmed.
Título: Enhanced alkaline cellulases production by the thermohalophilic Aspergillus terreus AUMC 10138 mutated by physical and chemical mutagens using corn stover as substrate
Fonte: Braz. j. microbiol;46(4):1269-1277, Oct.-Dec. 2015. tab, graf.
Idioma: en.
Resumo: Abstract A thermohalophilic fungus, Aspergillus terreus AUMC 10138, isolated from the Wadi El-Natrun soda lakes in northern Egypt was exposed successively to gamma and UV-radiation (physical mutagens) and ethyl methan-sulfonate (EMS; chemical mutagen) to enhance alkaline cellulase production under solid state fermentation (SSF) conditions. The effects of different carbon sources, initial moisture, incubation temperature, initial pH, incubation period, inoculum levels and different concentrations of NaCl on production of alkaline filter paper activity (FPase), carboxymethyl cellulase (CMCase) and β-glucosidase by the wild-type and mutant strains of A. terreus were evaluated under SSF. The optimum conditions for maximum production of FPase, CMCase and β-glucosidase were found to be the corn stover: moisture ratio of 1:3(w/v), temperature 45 °C, pH range, 9.0–11.0, and fermentation for 4, 4 and 7 day, respectively. Inoculum levels of 30% for β-glucosidase and 40% for FPase, CMCase gave the higher cellulase production by the wild-type and mutant strains, respectively. Higher production of all three enzymes was obtained at a 5% NaCl. Under the optimized conditions, the mutant strain A. terreus M-17 produced FPase (729 U/g), CMCase (1,783 U/g), and β-glucosidase (342 U/g), which is, 1.85, 1.97 and 2.31-fold higher than the wild-type strain. Our results confirmed that mutant strain M-17 could be a promising alkaline cellulase enzyme producer employing lignocellulosics especially corn stover.
Descritores: Aspergillus/enzimologia
Aspergillus/metabolismo
Celulases/metabolismo
Mutagênese
Zea mays/metabolismo
-Aspergillus/efeitos dos fármacos
Aspergillus/efeitos da radiação
Meios de Cultura/química
Egito
Metanossulfonato de Etila
Concentração de Íons de Hidrogênio
Lagos/microbiologia
Técnicas Microbiológicas
Cloreto de Sódio/metabolismo
Temperatura Ambiente
Raios Ultravioleta
Responsável: BR1.1 - BIREME


  7 / 17 LILACS  
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Id: lil-665841
Autor: Zanelato, A I; Shiota, V M; Gomes, E; Silva, R da; Thoméo, J C.
Título: Endoglucanase production with the newly isolated Myceliophtora sp. i-1d3b in a packed bed solid state fermentor
Fonte: Braz. j. microbiol;43(4):1536-1544, Oct.-Dec. 2012. graf, tab.
Idioma: en.
Projeto: FAPESP; . CNPq.
Resumo: This work is aimed to produce endoglucanase through solid state fermentation in a packed bed bioreactor with the use of the fungus Myceliophtora sp. I-1D3busing a mixture of wheat bran (WB) and sugar cane bagasse (SCB) as culture medium. Preliminary tests were performed in polypropylene plastic bags, controlling the variables temperature (40, 45, and 50ºC), initial moisture content (75, 80, and 85%, w.b.), and weight proportion SCB/WB (1:1, 7:3, and 9:1). The highest enzyme activities in plastic bags were obtained using the substrate proportion of 7:3, 50ºC temperature, and 80% initial moisture content (878 U/grams of dry solid). High activities of filter-paper cellulase and xylanase were also obtained in plastic bags and some results are reported. For the packed bed experiments, the temperature (45 and 50ºC) and the air flow rate (80, 100 and 120L/h) were the controlled variables. Activity of endoglucanase was similar to plastic bag tests. A longitudinal gradient of moisture content, was observed increasing from the bottom to the top of the reactor, even though the longitudinal enzyme activity profile was flat for almost the whole bed. Air flow rate did not affect enzyme activity, while experiments carried out at 50ºC showed higher enzyme activities. The maximum temperature peak observed was at about 6ºC above the process temperature.
Descritores: Celulases/análise
Fermentação
Fungos/enzimologia
Fungos/isolamento & purificação
Polipropilenos/análise
Polipropilenos/isolamento & purificação
Saccharum
Triticum
Xilanos/análise
-Amostras de Alimentos
Microbiologia Industrial
Métodos
Indústria de Plásticos
Tipo de Publ: Estudo Comparativo
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


  8 / 17 LILACS  
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Id: lil-665838
Autor: Luz, José Maria Rodrigues da; Nunes, Mateus Dias; Paes, Sirlaine Albino; Torres, Denise Pereira; Silva, Marliane de Cássia Soares da; Kasuya, Maria Catarina Megumi.
Título: Lignocellulolytic enzyme production of Pleurotus ostreatus growth in agroindustrial wastes
Fonte: Braz. j. microbiol;43(4):1508-1515, Oct.-Dec. 2012. graf.
Idioma: en.
Resumo: The mushroom Pleurotus ostreatus has nutritional and medicinal characteristics that depend on the growth substrate. In nature, this fungus grows on dead wood, but it can be artificially cultivated on agricultural wastes (coffee husks, eucalyptus sawdust, corncobs and sugar cane bagasse). The degradation of agricultural wastes involves some enzyme complexes made up of oxidative (laccase, manganese peroxidase and lignin peroxidase) and hydrolytic enzymes (cellulases, xylanases and tanases). Understanding how these enzymes work will help to improve the productivity of mushroom cultures and decrease the potential pollution that can be caused by inadequate discharge of the agroindustrial residues. The objective of this work was to assess the activity of the lignocellulolytic enzymes produced by two P. ostreatus strains (PLO 2 and PLO 6). These strains were used to inoculate samples of coffee husks, eucalyptus sawdust or eucalyptus bark add with or without 20 % rice bran. Every five days after substrate inoculation, the enzyme activity and soluble protein concentration were evaluated. The maximum activity of oxidative enzymes was observed at day 10 after inoculation, and the activity of the hydrolytic enzymes increased during the entire period of the experiment. The results show that substrate composition and colonization time influenced the activity of the lignocellulolytic enzymes.
Descritores: Celulases/análise
Ativação Enzimática
Fungos/crescimento & desenvolvimento
Pleurotus/crescimento & desenvolvimento
Pleurotus/isolamento & purificação
Xilanos/análise
-Agaricales
Biodegradação Ambiental
Amostras de Alimentos
Metodologia
Resíduos
Tipo de Publ: Estudo Comparativo
Estudos de Avaliação
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


  9 / 17 LILACS  
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Id: lil-665834
Autor: Odeniyi, Olubusola A; Onilude, Anthony A; Ayodele, Maria A.
Título: Characteristics of a â-1, 4-D endoglucanase from Trichoderma virens wholly applied in a palm-fruit husk-based diet for poultry layers
Fonte: Braz. j. microbiol;43(4):1467-1475, Oct.-Dec. 2012. graf, tab.
Idioma: en.
Resumo: The characteristics of an endoglucanase produced by a Trichoderma virens strain T9 newly isolated from a palm-fruit husk dump site, its physiological characteristics and enzyme production were studied. Whole cells of the depolymerizing-enzyme producing T. virens were applied to palm-fruit husk and bird performance characteristics when employed as poultry diet additive were considered. Endoglucanase activity in submerged fermentation was 1.6 nkat. Optimum activity was recorded at pH 6.0 and 55ºC. The enzyme retained 50% residual glucanase activity at 70ºC for 10 minutes. 1.0% Tween-80 and SDS yielded endoglucanase activity 2.15 times higher than the control. Activity wasboosted by 20mM Ca2+ (115.0%); 10mM K+ (106.5%); and was totally inhibited by 1mM Hg2+. The addition of T. virens -fermented palm-fruit husk with other layer feed components on the bird characteristics showed that change in bird weight between the control and test birds were not significantly different (p>0.05) but differed in terms of daily feed ingested (p<0.05). The feed to weight-gain ratio was best with the unmodified palm-fruit husk based diet (8.59). There was no significant difference in the egg weights from modified palm-fruit husk based diet and control (p>0.05). The shell thickness (0.64mm) and yolk content (23.61%) were highest in the microbially-modified husk diet. The alternative to maize based diets proffered by the application of T. virens -modified palm-fruit husk in poultry nutrition in terms of bird weight and feed to weight-gain ratio affords the poultry farmer an economic advantage and allows for a greater utilization of the maize in human diets.
Descritores: Celulases/análise
/análise
GLUCANA 1,ABBREVIATIONS AS TOPIC-BETA-GLUCOSIDASE/análise
Trichoderma/fisiologia
Trichoderma/isolamento & purificação
-Microbiologia Industrial
Metodologia
Tipo de Publ: Estudo Comparativo
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


  10 / 17 LILACS  
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Silva, Roberto da
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Id: lil-656675
Autor: Moretti, Marcia M. S; Bocchini-Martins, Daniela A; Silva, Roberto Da; Rodrigues, André; Sette, Lara D; Gomes, Eleni.
Título: Selection of thermophilic and thermotolerant fungi for the production of cellulases and xylanases under solid-state fermentation
Fonte: Braz. j. microbiol;43(3):1062-1071, July-Sept. 2012. ilus, graf, tab.
Idioma: en.
Resumo: Twenty-seven thermophilic and thermotolerant fungal strains were isolated from soil, decaying organic matter and sugarcane piles based on their ability to grow at 45ºC on medium containing corn straw and cardboard as carbon sources. These fungi were identified in the genera Aspergillus, Thermomyces, Myceliophthora, Thermomucor and Candida. The majority of the isolated strains produced xylanase and cellulases under solid state fermentation (SSF). The highest cellulase and xylanase productions were obtained by the cultivation of the strains identified as Aspergillus fumigatus M.7.1 and Myceliophthora thermophila M.7.7. The enzymes from these strains exhibited maximum activity at pH 5.0 and at 60 and 70ºC. The endo-glucanase from A. fumigatus was stable from 40ºC to 65ºC and both endo-glucanase and xylanase from M. thermophila were stable in this temperature range when in absence of substrate. The enzymes were stable from pH 4.0 to 9.0.
Descritores: Carbono/análise
Celulases/análise
Fermentação
Fungicidas Industriais/análise
Fungos Mitospóricos/enzimologia
Fungos Mitospóricos/isolamento & purificação
Condições do Solo
Xilanos/análise
-Ativação Enzimática
Métodos
Tipo de Publ: Estudos de Avaliação
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica



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