Extracellular enzymes production from sugar beet pulp by γ-irradiated mutants of Trichoderma reesei

Sugar beet pulp (SBP) represents a major source of lignocellulosic material (LCM) with considerable potential for use in biomass conversion to ethanol. In this study, Trichoderma reesei and its mutants was used for extracellular enzymes production from sugar beet pulp. Endo-glucanase, exoglucanase, β-glucosidase, pectinase and invertase activity was investigated. Also, the purity and composition of enzyme-rich protein samples were evaluated under denaturing conditions by SDS-PAGE. Mutant T. r nrcam5 produces high levels of cellobiase, which can be further improved by controlled culture conditions. In addition, this mutant strain produces good levels of exoglucanase, endoglucanase and FPase, which together with the exceptionally high levels of cellobiase, makes it a good candidate for obtaining cellulases for lignocellulosic SBP degradation. The T. reesei and T. r nrcam5 have both enzyme bonds of Cel6A (CBHII) and Cel7A (CBHI).The highest synergy was observed in FPase of T. r nrcam5, that containing of large amount of CBH I and CBH II and minor amount of EG. Our results indicate that T. r nrcam5 overproduces cellulases, ß-glucosidase, and the extracellular enzymes, which suggest, this strain maight be utilized as a biological agent and/or a source of enzymes for cellulose degradation in SBP.

Keywords:

Trichoderma reesei , γ-irradiation , SDS-Page , Sugar beet pulp , Cellulase