title: Detection of polyketide synthase and nonribosomal peptide synthetase biosynthetic genes from antimicrobial coral-associated actinomycetes.
abstract: The diversity and properties of actinobacteria, predominant residents in coral holobionts, have been rarely documented. In this study, we aimed to explore the species diversity, antimicrobial activities and biosynthetic potential of culturable actinomycetes within the tissues of the scleractinian corals Porites lutea, Galaxea fascicularis and Acropora millepora from the South China Sea. A total of 70 strains representing 13 families and 15 genera of actinobacteria were isolated. The antimicrobial activity and biosynthetic potential of fifteen representative filamentous actinomycetes were estimated. Crude fermentation extracts of 6 strains exhibited comparable or greater activities against Vibrio alginolyticus than ciprofloxacin. Seven of the 15 actinomycetes strains possess type I polyketide synthases (PKS-I) and/or nonribosomal peptide synthetases (NRPS) genes. Nine tested strains possess type II polyketide synthases (PKS-II). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these PKS and NRPS gene screening positive strains belong to genera Nocardiopsis, Pseudonocardia, Streptomyces, Micromonospora, Amycolatopsis and Prauserella. One PKS-I and four NRPS fragments showed <70% similarity to their closest relatives, which suggested the novelty of these genes. This study helps uncover the genetic capacity of stony coral-associated actinomycetes to produce bioactive molecules.
authors.affiliation: CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, People's Republic China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Jun-De
authors.initials: JD
authors.lastname: Dong
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Xiong-Ming
authors.initials: XM
authors.lastname: Luo
authors.forename: Si
authors.initials: S
authors.lastname: Zhang
mesh_terms: D039903:Actinobacteria / Q000145:classification* / Q000201:enzymology* / Q000235:genetics; D000818:Animals; D037421:Anthozoa / Q000382:microbiology*; D044822:Biodiversity; D002681:China; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000235:genetics*; D010802:Phylogeny; D048630:Polyketide Synthases / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D048630:Polyketide Synthases; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase