Metabolic Versatility and Bioactive Metabolite Potential of Pseudotabrizicola phototrophica sp. nov., an Aerobic Anoxygenic Phototroph from Intertidal Sediments

Marine microorganisms are prolific sources of bioactive natural products, yet bacteria from intertidal sediments remain underexplored. Here, we report the isolation and genomic characterization of Pseudotabrizicola phototrophica sp. nov. (strain L79T) from intertidal sediments of Xiaoshi Island, Yellow Sea, Weihai, China. Genome mining using antiSMASH 8.0 revealed seven biosynthetic gene clusters (BGCs) with pharmaceutical relevance, including a complete carotenoid (spirilloxanthin) cluster (confirmed by absorption spectroscopy at 367, 482, and 775 nm); an NRPS cluster for putative pyreudione-like compounds; a PKS cluster for 6-methylsalicylic acid, a bioactive polyketide; a terpene-precursor cluster for sodorifen; a butyrolactone-type cluster; a partial ectoine-related gene cluster; and a RiPP-like cluster potentially encoding a bufferin-like metallophore. Experimentally validated metabolic traits include polyhydroxybutyrate (PHB) biosynthesis (confirmed by TEM), thiosulfate oxidation (SOX), and assimilatory nitrate reduction to ammonium (ANRA). The identification of these BGCs—particularly the NRPS and PKS clusters linked to antimicrobial compounds—provides a genomic roadmap for future natural product discovery from this underexplored marine bacterium.