Antifouling potential of symbiotic marine bacterium Bacillus subtilis MUT:M15 associated with the cuttlefish Sepia sp.

Abstract

The antagonistic marine bacterium <em>Bacillus subtilis </em>MUT:M15 isolated from the surface of <em>Sepia</em> sp. was identified using 16S rRNA gene sequencing. Intracellular and extracellular extracts of this bacterium was screened for antibacterial and antifouling activities. The results showed that both intracellular and extracellular extracts substantially reduced the growth and attachment of biofilm-forming bacterium, <em>Alteromonas</em> sp. The antifouling coatings (ICE15M and ECE15M) prepared with the intracellular and extracellular extracts of <em>Bacillus subtilis </em>MUT:M15 showed that these coatings significantly reduced the settlement of microfouling (bacteria and microalgae) and macrofouling organisms (barnacle, tubeworm, bivalve and gastropod) on the test panels submerged in the seawater. The bioactive fractions isolated from both intracellular and extracellular extracts of <em>Bacillus subtilis </em>MUT:M15 using thin layer chromatography were identified as phthalate derivatives by gas chromatography and mass spectroscopy.