title: Inhibition of marine biofouling by bacterial quorum sensing inhibitors.
abstract: Seventy eight natural products from chemical libraries containing compounds from marine organisms (sponges, algae, fungi, tunicates and cyanobacteria) and terrestrial plants, were screened for the inhibition of bacterial quorum sensing (QS) using a reporter strain Chromobacterium violaceum CV017. About half of the natural products did not show any QS inhibition. Twenty four percent of the tested compounds inhibited QS of the reporter without causing toxicity. The QS inhibitory activities of the most potent and abundant compounds were further investigated using the LuxR-based reporter E. coli pSB401 and the LasR-based reporter E. coli pSB1075. Midpacamide and tenuazonic acid were toxic to the tested reporters. QS-dependent luminescence of the LasR-based reporter, which is normally induced by N-3-oxo-dodecanoyl-L-homoserine lactone, was reduced by demethoxy encecalin and hymenialdisin at concentrations >6.6 μM and 15 μM, respectively. Hymenialdisin, demethoxy encecalin, microcolins A and B and kojic acid inhibited responses of the LuxR-based reporter induced by N-3-oxo-hexanoyl-L-homoserine lactone at concentrations >0.2 μM, 2.2 μM, 1.5 μM, 15 μM and 36 μM, respectively. The ability to prevent microfouling by one of the compounds screened in this study (kojic acid; final concentrations 330 μM and 1 mM) was tested in a controlled mesocosm experiment. Kojic acid inhibited formation of microbial communities on glass slides, decreasing the densities of bacteria and diatoms in comparison with the control lacking kojic acid. The study suggests that natural products with QS inhibitory properties can be used for controlling biofouling communities.
authors: Department of Marine Science and Fisheries, College of Agricultural and Marine Sciences, Sultan Qaboos University, Sultanate of Oman. sergey@squ.edu.om
authors: Sergey
authors: S
authors: Dobretsov
authors: Max
authors: M
authors: Teplitski
authors: Mirko
authors: M
authors: Bayer
authors: Sarath
authors: S
authors: Gunasekera
authors: Peter
authors: P
authors: Proksch
authors: Valerie J
authors: VJ
authors: Paul
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D057219:Biofouling / Q000517:prevention & control*; D001688:Biological Products / Q000494:pharmacology*; D002861:Chromobacterium / Q000187:drug effects* / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D010860:Pigments, Biological / Q000378:metabolism; D011753:Pyrones / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D053038:Quorum Sensing / Q000187:drug effects*; D013720:Tenuazonic Acid / Q000494:pharmacology
chemical_list: D000903:Antibiotics, Antineoplastic; D001381:Azepines; D001688:Biological Products; D009842:Oligopeptides; D010860:Pigments, Biological; D011753:Pyrones; D011758:Pyrroles; D011759:Pyrrolidines; C076335:microcolin A; C076336:microcolin B; D013720:Tenuazonic Acid; C011890:kojic acid; C107079:hymenialdisine