Biosynthesis and extraction of cellulase produced by Trichoderma on agro-wastes

Cellulase is the most important enzyme in the world enzyme market, which can be synthesized by growing fungi on lignocellulosic substrates. In this study, cellulase was produced by using Trichoderma species. Twenty-three Trichoderma species were isolated and screened out for their cellulase-producing ability. Selected species, Trichoderma reesei, was further optimized on Leptochloa fusca, a perennial grass. For the higher production of enzyme, different culture conditions were optimized in flask fermenters. Our study points out that overall cellulase production was highest as 1.165 IU/ml/min at 70% moisture level, 120-h incubation period, 30 °C incubation temperature, 6 initial pH, 20% inoculum size, 0.3% NH₄NO₃ concentration and 0.3% concentration of surfactant (Tween 80), respectively. Under solid-state fermentation, the recovery of the cellulase from fermented substrate was optimized which yielded 1.785 IU/ml/min. Among different solvents tested, optimal extraction was attained by using citrate buffer. The optimal conditions for extraction were 90 min soaking time, 1:5 solid-to-solvent ratio, 140 revolution per minute agitation. It was detected that two washes were enough for maximum leaching of the enzyme. Results specify the admirable scope of utilizing kallar grass for biosynthesis of cellulase in solid-state fermentation employing Trichoderma reesei commercially.