Optimised cellulase production from fungal co-culture of Trichoderma reesei NCIM 1186 and Penicillium citrinum NCIM 768 under solid state fermentation

Microbial cellulases find applications in many industries and constitute a significant share of the world’s industrial enzyme market. In order to improve the cost function of the cellulose producing processes with enhanced yield and novel activities, superior bioprocesses are formulated these days. Intending to produce higher titre of cellulase enzyme, present study deals with fungal co-culture and to investigate its feasibility of producing higher cellulase titre via solid state fermentation (SSF). Various process parameters were optimized for induced cellulase production from the co-culture of Trichoderma reesei NCIM 1186 and Penicillium citrinum NCIM 768 in SSF. Among different low cost and easily available agricultural lignocellulosic waste, wheat bran was found to be the most suitable substrate. The highest cellulase yield of 6.71 FPU/gds is obtained on 6th day of fermentation using steam pre-treated wheat bran with 70 % moisture content when inoculated with 106 spores of mixed suspension at 30 °C and pH 5. A further possibility to use whole fermented matter for saccharification instead of extracted cellulase was also investigated with the aim of abolishing an extraction step. Akin sugar yield of 6.45 mg/mL and 6.58 mg/mL was obtained at 72 h of hydrolysis of steam pre-treated wheat bran, using cellulase extract and whole fermented matter, respectively. Fungal co-culture of T. reesei and P. citrinum in SSF results in the highest cellulase titre using low cost agricultural waste as a substrate, which can be further used for successful saccharification in the form of whole fermented matter or as extracted enzyme.