Production of cellulase in solid-state fermentation withTrichoderma reesei MCG 80 on wheat straw

Abstract

It is an accepted fact that ethanol production from lignocellulosic materials is not economical as yet because of the high cost of cellulase production. To reduce the cost of cellulase production, lignocellulosic material (wheat straw [WS]), a comparatively much cheaper substrate, was used instead of costly substrates (pure cellulose or lactose). A pan bioreactor was developed for solid-state fermentation (SSF) that required a small capital investment. High yields of complete cellulase system were obtained compared to that in the liquid-state fermentation (LSF) from WS, when treated with 4.25% NaOH at 121 °C for 1 h and mixed with Mandels’ medium. A complete cellulase system is defined as one in which the ratio of β-glucosidase activity to filter paper activity in the enzyme solution is close to 1.0. The cellulase system derived from SSF using the pan bioreactor gave more than 85% hydrolysis of delignified WS. The prototype pan bioreactor requires further improvements so that optimum quantity of substrate can be fermented to obtain high yields of complete cellulase system per unit space. The SSF process provides a means for the production of complete cellulase system for the economical bioconversion of renewable biomass into ethanol.