Improved production of cellulase by Trichoderma reesei (MTCC 164) from coconut mesocarp-based lignocellulosic wastes under response surface-optimized condition

Abstract

Experimental investigations were carried out to develop economic production process of cellulase using coconut mesocarp as an inexpensive lignocellulosic inducer while replacing commercial cellulose. Cellulase production was initially investigated from commercial cellulose in different submerged conditions using Trichoderma reesei (MTCC 164). Maximum enzyme production was achieved 6.3 g/l with activity level 37 FPU/ml in the condition where cellulose to water content ratio was maintained at 5:35 (W/V). To achieve similar maximum production of cellulase from coconut mesocarp, response surface methodology was implemented to optimize most influencing parameters. Most influencing nutritional parameters such as coconut mesocarp, glucose and peptone were optimized in the concentration ranges of 35 g/l, 35 g/l and 25 g/l, respectively. Selecting optimized parameter values, fermentations were conducted inside the fermenter with 2 L operating volume to ensure high concentration and activity profiles of enzyme. Enzyme concentration was achieved 7.20 g/l after 96 h of batch fermentation with specific activity levels of 42 FPU/ ml and CMCase 75 U/ml. Enzyme concentration was further improved to 9.58 g/l with activity levels of 54 FPU/ml and CMCase 93 U/ml by adopting sequential feeding of coconut mesocarp in fed-batch fermentation mode. The presence of pure cellulase in the sample was confirmed by FTIR analysis.