Secondary Metabolites Produced by the Marine Bacterium Halobacillus salinus That Inhibit Quorum Sensing-Controlled Phenotypes in Gram-Negative Bacteria

• Published in: Applied and Environmental Microbiology Vol. 75; no. 3; pp. 567 - 572
• Main Authors: Teasdale, Margaret E, Liu, Jiayuan, Wallace, Joselynn, Akhlaghi, Fatemeh, Rowley, David C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.02.2009; American Society for Microbiology (ASM)
• Subjects: Antagonists; Anti-Bacterial Agents - biosynthesis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibiosis; Bacillaceae - isolation & purification; Bacillaceae - metabolism; Bacillaceae - physiology; Bacteriology; Biofilms; Biological and medical sciences; Cellular biology; Chromobacterium violaceum; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Environmental Microbiology; Fundamental and applied biological sciences. Psychology; Genes, rRNA; Genotype & phenotype; Gram-negative bacteria; Gram-Negative Bacteria - drug effects; Gram-positive bacteria; Microbial Ecology; Microbiology; Molecular Sequence Data; Phenethylamines - chemistry; Phenethylamines - metabolism; Phenethylamines - pharmacology; Phylogeny; Quorum Sensing - drug effects; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Marine environment; Phenotype; Quorum sensing; Inhibition; Metabolite; Gram negative bacteria
• ISSN: 0099-2240; 1098-5336; 1098-6596
• DOI: 10.1128/AEM.00632-08

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 μg/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.