Validation of a novel sequential cultivation method for the production of enzymatic cocktails from Trichoderma...

The development of new cost-effective bioprocesses for the production of cellulolytic enzymes is needed in order to ensure that the conversion of biomass becomes economically viable. The aim of this study was to determine whether a novel sequential solid-state and submerged fermentation method (SF) could be validated for different strains of the Trichoderma genus. Cultivation of the Trichoderma reesei Rut-C30 reference strain under SF using sugarcane bagasse as substrate was shown to be favorable for endoglucanase (EGase) production, resulting in up to 4.2-fold improvement compared with conventional submerged fermentation. Characterization of the enzymes in terms of the optimum pH and temperature for EGase activity and comparison of the hydrolysis profiles obtained using a synthetic substrate did not reveal any qualitative differences among the different cultivation conditions investigated. However, the thermostability of the EGase was influenced by the type of carbon source and cultivation system. All three strains of Trichoderma tested (T. reesei Rut-C30, Trichoderma harzianum, and Trichoderma sp INPA 666) achieved higher enzymatic productivity when cultivated under SF, hence validating the proposed SF method for use with different Trichoderma strains. The results suggest that this bioprocess configuration is a very promising development for the cellulosic biofuels industry.