Genome mining reveals the biosynthetic potential of the marine-derived strain M10.

Marine streptomycetes are rich sources of natural products with novel structures and interesting biological activities, and genome mining of marine streptomycetes facilitates rapid discovery of their useful products. In this study, a marine-derived sp. M10 was revealed to share a 99.02% 16S rDNA sequence identity with that of s Ap1, and was thus named  s M10. To further evaluate its biosynthetic potential, the 7,207,169 bps of  s M10 genome was sequenced. Genomic sequence analysis for potential secondary metabolite-associated gene clusters led to the identification of at least three polyketide synthases (PKSs), six non-ribosomal peptide synthases (NRPSs), one hybrid NRPS-PKS, two lantibiotic and five terpene biosynthetic gene clusters. One type I PKS gene cluster was revealed to share high nucleotide similarity with the candicidin/FR008 gene cluster, indicating the capacity of this microorganism to produce polyene macrolides. This assumption was further verified by isolation of two polyene family compounds PF1 and PF2, which have the characteristic UV adsorption at 269, 278, 290 nm (PF1) and 363, 386 and 408 nm (PF2), respectively.  s M10 is therefore a new source of polyene metabolites. Further studies on  s M10 will provide more insights into natural product biosynthesis potential of related streptomycetes. This is also the first report to describe the genome sequence of  s-related strain.