Produção e caracterização de celulases e xilanases produzidas por Streptomyces thermocerradoensis I3 em fermentação semi-sólida

• Autor(a) principal: Gama, Aline Rodrigues
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6355
• topic: Atividade enzimática; Actinomicetos; Hemicelulase; Biomassa lignocelulósica; Enzymatic activity; Actinomycetes; Hemicellulase; Lignocellulosic biomass; CIENCIAS BIOLOGICAS::MICROBIOLOGIA

The use of carbohydrates derived from agricultural waste is important in the industry of food, textiles, paper, detergents, animal feed and in the production of bioethanol. Some filamentous bacteria are used in the enzymatic degradation processes, such as Streptomyces thermocerradoensis I3, which was isolated from soil and this work was selected for the production of cellulases and xylanases by growing in semi-solid fermentation (SSF) in medium supplemented with wheat bran (WB) as carbon source. S. thermocerradoensis I3 it was maintained for 4 days at 37 ° C and showed a higher production of Endoglucanase (2,92 U/mL) and Xylanase (12,34 U/mL) after 72 hours of cultivation and β-glucosidase (0,023 U/mL) and FPase (2,82 U/mL) after 96 hours of cultivation. The 96-hour extract was concentrated. The enzyme present in the concentrated extract presented molecular mass of 17 kDa. It showed activity for cellulase and xylanases confirmed by zimograms and enzymatic activities. The crude extract (EB) and the concentrated extract (EC) were analyzed for pH and temperature optima for activity of cellulases and xylanases. The results showed that the highest activity of the total cellulase (FPase) was at pH 6.0 at 60 °C (EB) and pH in the range 3.0 to 6.0 at 80 °C (EC); the endoglucanase has higher activity at pH 6.0 at 55 °C (EB and EC); xylanase showed higher activity at pH 8.0 at 70 °C (EB and EC). The xylanase activity of EB and EC showed thermostability 60% after 2 hours of incubation at 60 °C and the endoglucanase activity of EB and EC remained above 50% after 4 hours of incubation at 50 °C, 60 °C and 70 °C. Qualitative analysis observed by TLC (Thin layer chromatography) showed the production of oligosaccharides and xilooligômeros from the hydrolysis of different substrates. S. thermocerradoensis I3 successfully used the WB in SSF producing enzymes that have the characteristics necessary for their industrial application.