Produção e caracterização de celulases produzidas por um isolado de Bacillus sp. / Production and characterization of cellulases produced by isolated from Bacillus sp

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

During the composting process, degradation of organic waste is accomplished and driven by a succession of microbial populations exhibiting a broad range of functional capabilities. A total of 183 bacteria isolated from a composting process were evaluated for the capacity for hydrolyze cellulose. Out of that, after the first screening one isolate was selected for the further assays. Growth curves were done and every two hours sample was collected and enzyme activity, pH, viable cell count and endospores were determined. The isolate was evaluated for its ability to produce carboxymethyl cellulase in culture medium supplemented with four different substrates: carboxymethyl cellulose, microcrystalline cellulose, wheat straw and rice husk. The culture medium supplemented with carboxymethyl cellulose induced higher enzyme activity after 6 hours of incubation (0,12 UEA mL-1min-1). The highest CMCase activity was observed at 60°C (0,14 UEA mL -1 min-1) for both the crude and partially purified enzyme after 30 and 120 minutes of incubation, respectively. The best activity of the crude extract was observed at pH 9,0. The addition of detergent Triton X-100 (1,0%) to the purified enzyme, induced to a higher hydrolysis of the substrate (0,2 UEA mL-1min-1). Analysis by SDS-page allowed the observation of only one band in the gel suggesting one cellulase with a molecular mass of 20 kDa.

ASSUNTO(S)

carboximetilcelulose celulase bacillus

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