Efficient lignocellulolytic enzymes producing bacteria from Pangi-Chamba Himalayan niches: a potential for sustainable and greener biomass catalysis
摘要
High-altitude regions of the Pangi-Chamba Himalayas (PCH) provide a distinctive environment for isolating extremophilic lignocellulolytic bacteria. This study reports the isolation of lignocellulolytic enzyme-producing bacteria from decaying wood samples. Among 54 bacterial isolates, 24 demonstrated lignocellulose hydrolysis potential, producing laccase, xylanase, and cellulase enzymes. Eight morphologically distinct isolates belonging to the phylum Bacillota were selected for further experiments. Quantitative analysis identified Bacillus sp. PCH491 as an efficient producer of xylanase using alkaline-pretreated wheat straw, whereas Bacillus sp. PCH494 produced laccase using alkaline-pretreated sugarcane bagasse. Notably, Bacillus sp. PCH492 produced multiple enzymes, laccase, xylanase, and cellulase, using various agro-residues. Further, characterization of laccase and xylanase enzymes revealed activity across a broad pH (4.0-12.0) and temperature (4-90 ℃). Xylanase from Bacillus sp. PCH491 showed maximum activity (38.86 IU/mL) at pH 7.0 and 50 ℃, whereas laccase from Bacillus sp. PCH494 reached peak activity (31.20 IU/mL) at pH 3.0 and 50 ℃. SEM and FTIR analyses confirmed significant structural and functional group modifications in the biomass, highlighting these high-altitude isolates as robust candidates for industrial biorefineries.