Genomic and Untargeted\nMetabolomic Analysis of Secondary\nMetabolites in the Streptomyces griseoaurantiacus Strain MH191 Shows Media-Based Dependency for the Production of\nBioactive Compounds with Potential Antifungal Activity

Streptomyces species can\nform beneficial\nrelationships with hosts as endophytes, including the phytopathogen-inhibiting\nstrain, Streptomyces griseoaurantiacusMH191, isolated from wheat plants. Using genomic characterization\nand untargeted metabolomics, we explored the capacity of strain MH191\nto inhibit a range of fungal phytopathogens through the production\nof secondary metabolites. Complete genome assembly of strain MH191\npredicted 24 biosynthetic gene clusters. Secondary metabolite production\nwas assessed following culture on six different media, with the detection\nof 205 putative compounds. Members of the manumycin family, undecylprodigiosin,\nand desferrioxamine were identified as the predominant metabolites.\nAntifungal activity was validated for undecylprodigiosin and manumycin.\nThese compounds were produced from different BGCs, which showed similarity\nto asukamycin, undecylprodigiosin, and FW0622 gene clusters, respectively.\nThe growth of strain MH191 on different media illustrated the metabolic\nregulation of these gene clusters and the strain’s extended\nchemical potential, with the asukamycin gene cluster alone, producing\na variety of antifungal metabolites. The study highlights the extended\nchemical capability of strain MH191, which could be exploited as a\nbiological control agent for designing future crop protection solutions.