Deciphering Complex Carbohydrate Degrading Potential of Local Hot Spring Isolate Brevibacillus agri MX26 from Tuwa,...

Hot springs are a treasure of valuable biological substances due to unique microbial diversity. Brevibacillus agri MX26, a thermophilic bacterium, was isolated from the Tuwa hot spring (63-64 °C, pH 8.2-9.0) and showed a multiple complex carbohydrate degrading capability, such as cellulose, starch, pectin, mannan, agar, xylan, and alginate. Its metabolic versatility was confirmed by substrate-specific induction of carbohydrases. Biochemical characterization, strengthened by partial purification via ammonium sulfate precipitation and ion-exchange chromatography, and the enzymes demonstrated their activity over a broad temperature (37-90 °C) and pH range (3.0-10.0), confirming their thermostable nature. Whole genome analysis revealed that like other extremophiles Brevibacillus agri MX26 contains 177 contigs with an average GC content of 53.9 percent. Among 5572 annotated contig sequences (CDSs) 144 encodes CAZymes, crucial for the breakdown of complex carbohydrate-containing materials. The clustering of the CAZyme genes indicates that complex carbohydrate utilization pathways are operated in harsh conditions. While amylase, xylanase and cellulase activities have been reported in other strains of B. agri, the present study is the first to report mannanase, pectinase and alginate lyase activity in B. agri MX26. This combined genomic and biochemical method identifies B. agri MX26 as a promising candidate for industrial use, especially in the production of animal feed products, the breakdown of lignocellulosic biomass, and other industries needing strong and thermostable carbohydrate-active enzymes.

The online version contains supplementary material available at 10.1007/s12088-025-01529-1.