Enhancement of saccharification of corn stover by cellulolytic enzyme produced from biomass-degrading bacteria

Abstract

Enzymatic saccharification of corn stover can be enhanced by partially replacing commercial enzymes with bacterial crude enzyme extracts. Thus, in this study, three bacteria (Bacillus sp. A0, Bacillus sp. CH20S1, and Exiguobacterium sp. AS2B) were cultured in a media with corn stover as the substrate to produce crude enzyme extract and saccharify corn stover. The cultural conditions were monitored and optimized to maximize CMCase and xylanase activity in the crude enzyme extracts. After 72 h of hydrolysis of corn stover with diluted crude enzymes (DCE) from the three strains, reducing sugars ranging from 48.2 to 71.7 mg g-1 were released from non-pretreated and pretreated corn stover. Furthermore, the maximum reducing sugars of 316 and 321 mg g-1 were observed when 12 and 4 FPU g-1 of commercial cellulase were added to the DCE of the CH20S1 strain, respectively. It was shown that an effective combination of bacterial DCE with commercial enzymes could achieve higher saccharification of lignocellulosic biomass, which might be cost-efficient compared to their single-use. Overall, this study aims to show the enhanced enzymatic saccharification of corn stover.