Production of cellulase and hemicellulase from agricultural residues [corn hull]
1986
Khanok Ratanakhanokchai | Morakot Tanticharoen | Supaporn Chevadhanarak (King Mongkut's Institute of Technology Thonburi, Bangkok (Thailand). Faculty of Energy and Materials. Dept. of Biotechnology)
Mixed cellulolytic bacteria formerly grown in mineral salt media supplemented with alpha-cellulolytic was cultivated in media substituted with corn hull as carbon source. After 20 hours of growth, the culture filtrate had activities toward xylan (Oat, Sigma Chemical Co.), carboxymethyl cellulose (Sigma Chemical Co.) and Beta-nitrophenyl-beta-D-xylopyranoside (Sigma Chemical Co.). The produced enzymes were 39 u/ml. exylanase, 8 u/ml. cellulase and 5 u/ml. Beta-xylosidase. The optimum condition were 40 deg Celsius, initial pH 7.0 and 20-30 mesh corn hull for enzymatic production. The adding cellobiose, xylose or glucose to corn hull media resulted in a higher peak production of enzyme. The best result was obtained with 0.25 % xylose and xylanase was 86 u/ml. The presence of sugar alone in mineral salt media did not induce any enzyme activity. The chemical analysis of corn hull after bacterial degradation showed that 36 percent of hemicellulose was used whereas cellulose degradation was very low. The optimum conditions for enzymatic activity against xylan were 50 deg Celsius at pH 6.0-6.5. The hydrolysis of corn hull by these enzymes yielded mainly xylose.
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