Profiling of oxidative enzymes and structural characterization of biologically pretreated oil palm wood chips

Globally, biological pretreatment has become a new interest among researchers as a substitute pretreatment for a cleaner and greener technology approach to the waste management program. The study comprehensively examined the chemical changes in oil palm lignocellulosic materials pretreated with three species of wood degraders, namely, Lentinus tigrinus strain FBJG3, Clitopilus prunulus strain ST3, and Trametes lactinea strain FBW. The findings were used to limit potential wood degrader (s) for the secretion of oxidative enzymes, i.e., laccase, manganese peroxidase and lignin peroxidase, using principal component analysis (PCA). Among them, L. tigrinus and T. lactinea were selected as potential candidates, with a significant amount of laccase enzyme produced with 8.8-fold and 1.2-fold increase towards the end of biological pretreatment period (Day 120). Syringyl (S) to guaiacyl (G) ratio decreased as the degradation progressed in the wood chips pretreated with L. tigrinus, suggesting that this strain preferentially attacked the S-lignin units. Conversely, the increase in the S/G ratio in wood chips pretreated with T. lactinea was observed, suggesting that this strain preferably attacked the G-lignin units. This study provides a new overview of chemical changes during biological pretreatment of oil palm lignocellulosic materials. These findings could be used to selectively pretreat lignocellulosic materials during replanting of oil palm. As in the case of conventional replanting, the diseased palms are left for natural degradation.

Automated summary

Biological pretreatment has gained attention as a cleaner and greener approach to waste management. This study examined the chemical changes in oil palm lignocellulosic materials pretreated with three wood degraders and identified potential candidates for enzyme secretion. The findings provide a new overview of chemical changes during biological pretreatment.