title: Secondary metabolites produced by the marine bacterium Halobacillus salinus that inhibit quorum sensing-controlled phenotypes in gram-negative bacteria.
abstract: Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a Halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by Vibrio harveyi in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by Chromobacterium violaceum CV026 and green fluorescent protein production by Escherichia coli JB525. Bacterial growth was unaffected at concentrations below 200 microg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with N-acyl homoserine lactones for receptor binding.
authors.affiliation: Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, 02881, USA.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Teasdale
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Liu
authors.forename: Joselynn
authors.initials: J
authors.lastname: Wallace
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Akhlaghi
authors.forename: David C
authors.initials: DC
authors.lastname: Rowley
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology*; D000898:Antibiosis; D001406:Bacillaceae / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D020459:Genes, rRNA; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D008969:Molecular Sequence Data; D010627:Phenethylamines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D010802:Phylogeny; D053038:Quorum Sensing / Q000187:drug effects*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010627:Phenethylamines; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S