Functional and genomic characterization of ligninolytic Bacillus strains for improved jute fibre delignification.

Lignin, the second most abundant biopolymer on Earth, imparting rigidity to plant cell walls but poses a challenge in the processing of lignocellulosic biomass such as jute (Corchorus spp.). Compared to other bast fibers such as flax and ramie, jute fiber has a very high lignin content (13.3% to 15%), hindering its use in the textile sector. Although chemical methods for lignin degradation are widely used, they are environmentally damaging and economically unfeasible. Consequently, bacterial lignin-degrading enzymes, especially those derived from Bacillus species, have attracted interest owing to their resilience and adaptability. This study investigated three Bacillus strains-LJRB1 (Bacillus subtilis), LJRB2 (Bacillus amyloliquefaciens), and LJRB3 (Bacillus licheniformis)-which were identified for their efficient lignin-degrading capabilities. Comprehensive characterization of these strains was performed, including growth condition optimization, enzyme profiling (MnP and LiP), and genomic analysis via whole-genome sequencing to identify key ligninolytic genes. These strains, if combined with previously proven high-efficiency pectinolytic strains (PJRB 1-3) will enhance the microbial retting consortium by simultaneously reducing the fiber lignin content and retting time. These findings lay the foundation for the development of a next-generation microbial retting formulation that is eco-friendly, cost-effective, and industry-oriented, potentially enhancing the quality and marketability of jute fiber for high-end applications.