Unraveling lignocellulosic xylan degradation by a novel strain of Streptomyces sp.: an exploration through genomic and transcriptomic perspectives.

A strain of Streptomyces sp., KAU_LT, possessing industrial significance and exhibiting xylanase activity at a level of 5088.92 ± 167.22 IU/gds, was isolated and characterized. The xylanase enzyme exhibited remarkable tolerance and stability across a wide pH range (6.0-10.0) and temperatures up to 70 °C. Media optimization resulted in 20-fold increased enzyme production during Solid-State Fermentation, bypassing the necessity for agro-residue pre-treatment. The whole genome sequencing through Illumina-Nanopore hybrid strategy followed by annotation has revealed its extensive carbohydrate-active enzyme repertoire. The 16S rRNA phylogenetic analysis has identified the strain as a relative of the novel Streptomyces nigra. The transcriptome sequencing and analysis identified endo-1,4-β-xylanase (xlnB) as one of the top upregulated genes. Among the xylanolytic genes predicted from the whole genome annotation, xlnB was 660-fold upregulated, contributing to most of the xylan degradation during Solid-State Fermentation process. The strain's capability to produce xylo-oligosaccharides highlights its applications across diverse industries.