title: Novel nonribosomal peptide synthetase (NRPS) genes sequenced from intertidal mudflat bacteria.
abstract: Nonribosomal peptide synthetases (NRPS) are actively sought out, due to pharmacologically important activities of their metabolites. In marine environment, the most prevalent nonribosomal peptide antibiotic producers are sponges inhabiting microorganisms. Conversely, strains from marine sediments and more especially from intertidal mudflats have not been extensively screened for the presence of new NRPS. In this study, for the first time, a collection of one hundred intertidal mudflat bacterial isolates (Marennes-Oléron Bay, France) was assessed for (1) the presence of NRPS genes by degenerated PCR targeting conserved adenylation domains and (2) for their production of antimicrobial molecules. (1) Bacteria with adenylation domains (14 strains) were identified by 16S rRNA gene sequence analysis and grouped into Firmicutes (one strain) and Proteobacteria (13 strains). In silico analysis of the NRPS amino acid sequences (n = 7) showed 41-58% ID with sequences found in the NCBI database. Three new putative adenylation domain signatures were found. (2) The culture supernatant of one of these strains, identified as a Bacillus, was shown to strongly inhibit the growth of Staphylococcus aureus, S. epidermidis, and Enterococcus faecalis. This study portends that the intertidal mudflat niche could be of interest for the discovery of new NRPS genes and antimicrobial producing strains.
authors.affiliation: Laboratoire Littoral Environnement et Sociétés, Université de La Rochelle, LIENSs - UMR 7266 - CNRS, La Rochelle Cedex 1, France.
authors.forename: Fatoumata
authors.initials: F
authors.lastname: Tambadou
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lanneluc
authors.forename: Sophie
authors.initials: S
authors.lastname: Sablé
authors.forename: Géraldine L
authors.initials: GL
authors.lastname: Klein
authors.forename: Ibtissem
authors.initials: I
authors.lastname: Doghri
authors.forename: Valérie
authors.initials: V
authors.lastname: Sopéna
authors.forename: Sandrine
authors.initials: S
authors.lastname: Didelot
authors.forename: Cyrille
authors.initials: C
authors.lastname: Barthélémy
authors.forename: Valérie
authors.initials: V
authors.lastname: Thiéry
authors.forename: Romain
authors.initials: R
authors.lastname: Chevrot
mesh_terms: D000890:Anti-Infective Agents / Q000378:metabolism; D000898:Antibiosis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005602:France; D019015:Geologic Sediments / Q000382:microbiology*; D006094:Gram-Positive Bacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000235:genetics*; D020560:Proteobacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase
keywords: NRPS; antimicrobial peptide; degenerate primers; intertidal mudflat; nonribosomal peptide