Metabolites Discovery from Streptomyces xanthus: Exploring the Potential of Desert Microorganisms

The Taklamakan Desert is an extreme environment supporting a unique and diverse microbial community with significant potential for exploration. Strain TRM70308^T, isolated from desert soil, shares 98.43% 16S rRNA gene sequence similarity with <i>Streptomyces alkaliterrae</i> OF1^T. Polyphasic taxonomy confirmed TRM70308^T as a novel species, named <i>Streptomyces xanthus</i>. Genomic analysis revealed that only one of the strain's 25 biosynthetic gene clusters (BGCs) formed a cluster of gene families (CGFs) within the MIBiG database, emphasizing its genomics uniqueness. LC-MS/MS and Feature-Based Molecular Networking (FBMN) identified 33 metabolites across various categories, including alkaloids, saponins, benzoic acids, and benzofurans, most of which remain uncharacterized. Further chemical investigation led to the isolation of one novel compound, aconicarpyrazine C, and four known compounds: thiolutin, dibutyl phthalate, bis(2-ethylhexyl) phthalate, and <i>N</i>-acetyltryptamine. Thiolutin exhibited strong activity against five local fungal pathogens that cause plant diseases, with a production yield of 270 mg/L. These results establish a foundation for pilot-scale thiolutin production and its potential development as an antifungal agent for agricultural applications. Our findings highlight deserts as a valuable source of novel actinomycetes and bioactive natural products with immense potential for future research and development.