Manganese peroxidase-mediated biological pretreatment of lignocellulosic biomass for enhanced enzymatic saccharification and bioenergy production

Abstract:

The recalcitrant lignin barrier in lignocellulosic biomass constitutes the principal impediment to efficient enzymatic saccharification for second-generation bioethanol production, exemplifying the need for effective and environmentally sustainable pretreatment technologies. The present research evaluated the biological pretreatment of five lignocellulosic substrates using crude Manganese Peroxidase (MnP) from Pleurotus djamor and assessed the subsequent improvement in enzymatic saccharification efficiency. Sugarcane bagasse exhibited the highest lignin removal (44.6±3.2%) after 6 weeks of MnP treatment, followed by rice straw (42.8±2.8%), corn stover (38.4±2.6%), wheat straw (36.2±2.4%), and bamboo chips (28.4±2.2%). MnP pretreatment selectively degraded lignin while preserving 82.4-94.2% of cellulose content. Enzymatic saccharification with commercial cellulase yielded 68.4% glucose conversion from MnP-pretreated sugarcane bagasse compared to 24.6% from untreated controls, representing a 2.78-fold improvement. These findings demonstrate the efficacy of P. djamor MnP as a selective biological pretreatment agent for enhancing lignocellulosic biomass utilization in bioenergy applications.