Sustainable agent of compost-derived bacteria for enhanced biological hydrolysis and saccharification of Napier grass

This study developed a biological hydrolysis process for lignocellulosic biomass using compost-derived bacteria. Napier grass (Pennisetum purpureum), a high-yield non-food feedstock, was selected as the substrate. Two strains, Klebsiella variicola and Microbacterium aurum, were isolated, with K. variicola showing the highest hydrolytic efficiency, yielding 1,900 mg L^-1 of sugar and no furfural under mesophilic (37 °C) aerobic conditions. The optimal condition for sugar release and solid degradation was obtained at a substrate concentration of 15,000 mg VS L^-1 and 37 °C. Scanning Electron Microscope (SEM) analysis confirmed fiber disruption of Napier grass after treatment. Klebsiella variicola demonstrated strong potential as an effective biological pretreatment agent for lignocellulosic biomass, achieving high sugar yields without generating inhibitory compounds. The proposed aerobic hydrolysis process represents a sustainable and scalable strategy for biomass valorization, contributing to the development of circular bioeconomy and clean energy technologies.