Caracterização de Enzimas Celulolíticas Produzidas pelo fungo Filamentoso Penicillium citrinum

Abstract

Cellulolytic enzymes are highly specific biocatalysts. These are classified according to the place where they work in the cellulosic fiber: endoglucanases initiate hydrolysis exoglucanases act on reducing terminals produced by endoglucanases and β-glucosidases act on the product of catalysis of exoglucanases releasing glucose monomers . Penicillium fungi are widely reported as a great producer of cellulolytic enzymes. Aiming to contribute to the catalytic process and obtaining new sources of enzymes , this study evaluated the physicochemical properties of enzymes produced cellulolytic fungus Penicillium citrinum isolated from bagasse cane sugar mill Jayoro of S / A, located in the municipality of Presidente Figueiredo -AM - Brazil . And the enzyme production profile was repaired during submerged fermentation with the strain of Trichoderma reesei QM9414 which is widely reported as a great producer of cellulolytic enzymes. P. citrinum showed equivalent performance to T. reesei QM9414 in volumetric enzyme activity (U/mL) and superior performance in specific activities (U/mg). About properties of endoglucanases and β-glucosidase from P. citrinum, the optimum temperature for activity was 60 ° C for both enzymes. The optimum pH for endoglucanases activity was pH 4.2 and the activity of β-glucosidase pH 6.0. P. citrinum produced at least two endoglucananes with apparent molecular masses of ~ 50kDa and ~ 35kDa , visualized on SDS-PAGE gels and in gel activity ( zymogram ) . An elution fraction obtained from size exclusion chromatography, showed only β-glucosidase activity and revealed bands of approximately 100 kDa . The performance and characteristics of these endo and β- glucosidases demonstrate that P. citrinum represents a new alternative for production of cellulolytic enzymes for hydrolysis of fiber.