Enhanced reducing sugar production by saccharification of lignocellulosic biomass, Pennisetum species through cellulase from a newly isolated Aspergillus fumigatus

Abstract

A cellulose degrading fungus Aspergillus fumigatus (CWSF-7) isolated from decomposed lignocellulosic waste containing soil was found to produce high titer of cellulases. The optimum activity of CMCase and FPase were 1.9 U/mL and 0.9 U/mL respectively while the highest protein concentration was found to be 1.2 mg/mL. Saccharification of two Pennisetum grass varieties [dennanath (DG) and hybrid napier grass (HNG)] were optimized using partially purified CMCase and FPase in equal concentration, i.e. a ratios of 1:1 and further with addition of commercial xylanase using response surface methodology (RSM). The production of total reducing sugar (TRS) using isolated cellulase were 396.6 and 355.8 (mg/g), whereas further addition of xylanase had higher TRS titers of 478.7 and 483.3 (mg/g) for DG and HNG respectively as evident from HPLC analysis. Further, characterization of the enzyme saccharified DG and HNG by SEM and ATR-FTIR revealed efficient hydrolysis of cellulose and partially hydrolysis of hemicellulose.