Application of Different Pretreatment Methods for Delignification of Lignocellulosic Biomass

Abstract

The major hindrance in biofuel production from lignocellulosic biomass is the presence of lignin which restricts the accessibility of hemicellulose and cellulose. This study investigates the different chemical and biological pretreatment methods for breakdown of the lignocellulosic sugarcane bagasse, garden waste and coconut husk to enhance accessibility of hemicellulose and cellulose. In this study, a yeast bacteria consortium of two strains Rhodosporidium toruloides and Bacillus aryabhattai have been constructed for the biological pretreatment process. Ultrasound-assisted alkaline pretreatment and surfactants facilitated glycerol organosolv pretreatment methods have been applied for the chemical pretreatment. Biological pretreatment has been done with single cultures of Rhodosporidium toruloides and Bacillus aryabhattai and the constructed consortium culture. The experimental results showed ultrasound-assisted alkaline pretreatment method to be effectively applied to enhance delignification. The exposure of free cellulose surfaces was confirmed by the XRD crystallinity index values. Comparative assessments of the pretreated samples were performed. The sample pretreated with consortium culture showed enhanced crystallinity index value as compared to the single microbial culture. The microbial community selected here indicated as a potential consortium culture for the degradation of waste lignocellulosic biomass. These pretreated samples are further utilized for bioethanol production, contributing to waste valorization and circular bioeconomy strategies.