Produção e caracterização de celulases e hemicelulase produzidas por Pycnoporus sanguineus

Abstract

Lignocellulosic residues are by-products generated during industrial processing from agricultural products and activities, and can be used in conjunction with microorganisms for the production of high added value biomolecules, such as enzymes. In this context, the present study aimed to produce and characterize cellulases and hemicellulase by cultivation in solid state by the fungus Pycnoporus sanguineus using agroindustrial residues as substrate. The production of endoglucanase, β-glucosidase and xylanase by Pycnoporus sanguineus was optimized, obtaining 63.04 ± 2.39, 32.35 ± 0.66 and 11.28 ± 0.78 Ug-1 of dry substrate, respectively. 96 - 120 hours of wheat bran cultivation. The optimal activity for endoglucanase was obtained at pH 5.0 and 70ºC; for β-glucosidase it was pH 4.0 and 70ºC and for xylanase pH 5.5 and 75ºC. Regarding pH stability, the enzyme endoglucanase remained stable in the range of 3.5 - 8.0; β-glycosidase was in the range of 4.0 - 7.0 and xylanase was 3.0 - 6.0. In the evaluation of thermostability, the enzyme endoglucanase was stable in the temperature range of 30 - 60ºC, β-glucosidase 30 - 55ºC and xylanase 30 - 65ºC. Β-glucosidase was strongly inhibited by glucose, retaining about 50% of its original activity in a solution containing 25 mM of glucose. The same enzyme showed catalytic stability when incubated in a solution containing 15% ethanol, which enables its use in alcoholic fermentation processes. The fungus Pycnoporus sanguineus showed potential for enzyme production when grown on a low added value substrate (low cost) and its enzymes showed promising characteristics for industrial application, due to the high stability at pH and temperature.