Improved saccharification of pilot-scale acid pretreated wheat straw by exploiting the synergistic behavior of lignocellulose degrading enzymes

Abstract

Requirement of high enzyme dosage for lignocellulosic biomass hydrolysis is one of the challenges for the viability of the second generation bioethanol technology. Here, an optimal enzyme mixture was developed by partially replacing the cellulase proportion with accessory enzymes (β-glucosidase, xylanase, pectinase, laccase) and its hydrolytic performance was compared with different commercial counterparts for the saccharification of pretreated wheat straw (PWS) using a 250 kg per day continuous pilot plant. Maximum degree of synergism was observed with xylanase followed by pectinase, laccase, and β-glucosidase. The statistically optimized enzyme mixture enhanced hydrolysis by 51.23% and 40.66% in 6 h and 24 h, respectively. This study elucidates that presence of even small amount of oligomers and cellobiose pose a strong inhibition for the enzymes. Therefore, development of an optimal enzyme formulation is a sustainable approach to reduce overall enzyme loading for biomass saccharification.