Optimization of Lignocellulolytic Enzyme Production by Pleurotus eryngii WC 888 utilizing Agro-Industrial Residues and Bio-ethanol Production

Researchers have been re-directing their interest in biomass-based bio-fuels, biocatalysts and other value-able biomaterials to expand the range of natural resources as alternate feedstock. In the present study, lignocellulolytic enzyme production efficiency of Pleurotus eryngii WC 888 was investigated using cost-effective agro-industrial residues in solid-state fermentation (SSF). A pilot-scale fermentation experiment was conducted for 10 days and enzyme activities were determined in units/ml. The SSF of banana stalk by P. eryngii WC 888 ensured the highest level of laccase activity (160.25 U ml(-1)), followed by MnP (143.45 U ml(-1)) and LiP (68.2 U ml(-1)). On the contrary, very low cellulose-degrading enzyme activities were detected in the fermented culture under the same conditions. Response surface methodology (RSM) with central composite design (CCD) was adopted to optimize the culture conditions. The optimum conditions that gave maximum enzyme secretion were; pH, 4; temperature, 35 degrees C; inoculum size, 4 ml; incubation time, 120 h and moisture content, 60%. The crude extract produced was used for the delignification and saccharification of various plant residues for bioethanol production. The preliminary results suggested that lignocellulosic wastes could be utilized as low-cost substrate for the production of enzymes which play significant role in many industrial and biotechnological sectors.