Benchmarking hydrolytic potential of cellulase cocktail obtained from mutant strain of Talaromyces verruculosus IIPC 324 with commercial biofuel enzymes

Abstract

In the present study, an attempt was made to benchmark the hydrolytic potential of cellulase cocktail obtained from stable mutant UV-8 of Talaromyces verruculosus IIPC 324 (NFCCI 4117) with three commercially available cellulases. With two experimental approaches, acid-pretreated sugarcane bagasse was subjected to hydrolysis for 72h, where all the enzymes were dosed on the basis of common protein or common cellulase activity /g cellulose content. Concentrated fungal enzyme (CFE) of mutant UV-8 resulted in ~ 59% and 55% saccharification of acid-pretreated sugarcane bagasse after 72h at 55°C and pH 4.5 with respect to reducing sugar release, when dosed at 25mgprotein/g and 500IU CMC'ase/g cellulose, respectively. On the other hand, at similar dosages, the performance of Cellic CTec2 was best resulting in 77% and 66% saccharification, respectively. When enzyme desorption studies were undertaken by carrying out cellulase activities in saccharified broth after 72h CFE of UV-8 emerged as the best cellulase cocktail. A minimum of 90% endoglucanase and 60% cellobiohydrolase I was successfully desorbed from residual biomass, thereby increasing the probability of enzyme recycle and reuse for next round of hydrolysis.