In Vitro and In Silico Antifouling Activity Analysis of Secondary Metabolites Extracted from the Marine Bacterium Vibrio alginolyticus

The bacteria associated with marine invertebrates are considered as a potential source of biologically active compounds. In the present study, the bacterium Vibrio alginolyticus obtained from the shell surface of the marine gastropod Turbo intercostalis displayed strong antibacterial activity in the preliminary screening against biofilm-forming bacteria. Further antibiofilm assay exhibited that the extract of V. alginolyticus substantially inhibited the biofilm forming ability of Alteromonas sp. Moreover, the extract of V. alginolyticus showed significant antifouling activity against the marine biofouling organisms in the field study conducted in the coastal waters. In addition, the active components of the extract were eluted by chromatography methods and analysed using gas chromatography and mass spectroscopy (GC-MS). The obtained GC-MS spectrum indicated the presence of the compounds such as 1H-Indole, 5-methyl-2-phenyl, 2-Ethylacridine and diethyl bis (trimethylsilyl) silicate. The in silico analysis of the identified compounds was carried out against the molecular target barnacle cement protein. The compound 2-Ethylacridine showed promising activity than the other compounds including the reference antifouling agent 5-Dichloro-2-n-octyl-4-isothiazolin-3-one. In conclusion, results of this study indicated the antibiofilm and antifouling activities of the compounds produced by the bacterium V. alginolyticus. These compounds could serve as potential leads for the development of natural product-based antifouling agents.