PRODUCTION OF AN EXTRACELLULAR CELLOBIASE IN SOLID STATE FERMENTATION

The bioethanol production from lignocellulosic biomass has attracted wide interest globally in last decade. One of the main reasons for the high cost of bioethanol production from lignocellulosic biomass is the expensive enzymes involved in enzymatic hydrolysis of cellulose (cellulase). The utilization of agro-industrial waste as a potential substrate for producing enzymes may serve a dual purpose of reducing the environmental pollution along with producing a high value commercial product. Twelve different agro-industrial wastes were evaluated for extracellular cellobiose or β-glucosidase production by a mutant of Bacillus subtilis on solid state fermentations (SSF). The Citrus sinensis peel waste was found to be the most suitable substrate with highest BGL titre (35 U/gds). Optimum incubation time, inoculum size, moisture content and volume of buffer for enzyme extraction were 72 h, 40 % v/w, 10 mL and 20 mL respectively.