Jute sticks biomass delignification through laccase-mediator system for enhanced saccharification and sustainable release of fermentable sugar

Abstract

Jute sticks obtained after the extraction of jute fiber are an excellent biomass feedstock with a significant amount of carbohydrates that makes it an attractive resource for sustainable energy generation. However, the high lignin content in the jute stick hinders the cellulosic component of the cell wall from enzymatic hydrolysis.This work demonstrates the lignin degradation of jute stick biomass by Trametes maxima laccase in the presence of mediator Hydroxybenzotriazole and improvement in its subsequent saccharification. Lignin component in jute stick is reduced by 21.8% in a single reaction treatment with laccase-mediator compared to the untreated jute stick sample used as control. The yield of fermentable sugar is increased by 19.5% that verifies enhanced saccharification after lignin removal. Delignification of jute stick was corroborated through different analytical techniques. The Pyrolysis gas chromatography/mass spectrometry results further confirms abundance of S lignin unit in the jute stick compared to the H and G unit and modification in lignin polymer as a change in the syringyl-to-guaiacyl ratio. Hence, this work demonstrates that jute stick can be effectively delignified using biocatalyst-mediator system and utilized as biomass source, thus contributing in circular bio-economy through waste valorization.