Antagonistic activity of an epibiotic Bacillus strain SG3 from Gorgonian coral, Junceella juncea (Pallas, 1766)

Abstract

Marine environment continues to be a huge source of pharmacologically active compounds that cure deadly disease. This research investigates the bioactive efficacy of bacteria isolated from surface of the coral, Junceella juncea (Pallas, 1766). 128 bacterial strains were isolated from the coral Junceella juncea from Tuticorin coast, Gulf of Mannar region, south east coast of India. The strains were tested against selected five human pathogens. Initial screening shows that the strain SG3 was found to exhibit broad spectral activity inhibiting Staplylococcus aureus. Also, twenty other strains were found to be active against various pathogens. Based on 16S rRNA sequencing and phylogenetic identification, the stain SG3 was identified to fell under the genera Bacillus. The ethanol precipitated of the culture broth (SG3) was done and its activity was noted. Mass spectrophotometry (MALDI-TOF) analysis has shown that the mass of the molecules ranged from 1225 Da to 1927 Da. Thus the marine bacteria isolated from corals are a potential source of novel bioactive agents and other natural products. Epibiotic bacteria also direct future isolation of peptide anti-MRSA compounds from marine source.