Amicoumacins from a desert bacterium: quorum sensing inhibitor against .

In our study, the anti-quorum sensing (QS) activity of fermentation broth from TRM B-02, a bacterium isolated from Taklimakan desert, was investigated using the biosensor bioassay on ATCC12472. TRM B-02 was 100% similar to subsp. Inaquosorum KCTC 13429 by genotypic and phenotypic analyses. Based on anti-QS activity tracking, six known amicoumacins, named as AI-77-H (), AI-77-F (), amicoumacin B (), amicoumacin C (), AI-77-C () and bacilosarcins D (), were isolated and identified. Among them, compounds exhibited a better inhibitory effect on ATCC12472. Further research suggested that compounds - could significantly down-regulate the expressions of violacein operon A (vioA), vioB, vioD and vioE and up-regulate vioC. Docking experiments indicated that compounds may act as an inhibitor of violacein biosynthetic pathway competitively inhibiting the binding of flavin adenine dinucleotide (FAD) with the vioD enzyme.[Figure: see text].