biostudies-literatureUnknown78(14)Cude WNMembers of the Roseobacter lineage of marine bacteria are prolific surface colonizers in marine coastal environments, and antimicrobial secondary metabolite production has been hypothesized to provide a competitive advantage to colonizing roseobacters. Here, we report that the roseobacter Phaeobacter sp. strain Y4I produces the blue pigment indigoidine via a nonribosomal peptide synthase (NRPS)-based biosynthetic pathway encoded by a novel series of genetically linked genes: igiBCDFE. A Tn5-based random mutagenesis library of Y4I showed a perfect correlation between indigoidine production by the Phaeobacter strain and inhibition of Vibrio fischeri on agar plates, revealing a previously unrecognized bioactivity of this molecule. In addition, igiD null mutants (igiD encoding the indigoidine Applied and environmental microbiology4771-80https://www.ebi.ac.uk/biostudies/studies/S-EPMC3416362biostudies-literatureProduction of the antimicrobial secondary metabolite indigoidine contributes to competitive surface colonization by the marine roseobacter Phaeobacter sp. strain Y4I.PMC3416362May ALFrank AMMooney JHadden MKBuchan ACude WNGulvik CATavanaei AAfalseProduction of the antimicrobial secondary metabolite indigoidine contributes to competitive surface colonization by the marine roseobacter Phaeobacter sp. strain Y4I.Members of the Roseobacter lineage of marine bacteria are prolific surface colonizers in marine coastal environments, and antimicrobial secondary metabolite production has been hypothesized to provide a competitive advantage to colonizing roseobacters. Here, we report that the roseobacter Phaeobacter sp. strain Y4I produces the blue pigment indigoidine via a nonribosomal peptide synthase (NRPS)-based biosynthetic pathway encoded by a novel series of genetically linked genes: igiBCDFE. A Tn5-based random mutagenesis library of Y4I showed a perfect correlation between indigoidine production by the Phaeobacter strain and inhibition of Vibrio fischeri on agar plates, revealing a previously unrecognized bioactivity of this molecule. In addition, igiD null mutants (igiD encoding the indigoidine 2012-01-01T00:00:00Z2012 Jul2026-04-29T16:31:19.443Z2019-03-27T00:56:38ZS-EPMC34163622258205510.1128/aem.00297-1210.1128/AEM.00297-12