Isolation Of Pigmented Marine Bacteria Exiguobacterium Sp. From Peninsular Region Of India And A Study On Biological Activity Of Purified Pigment

Abstract During the past two decades research on marine bacteria has highlighted the tremendous potential of these microorganisms as a source of new bioactive secondary metabolites and it is reported that most of the marine bacterial pigments exhibited antimicrobial activity. In the present study Pigmented marine bacteria were isolated from water samples collected from Marina beach Chennai Rameshwaram Tuticorin and Cochin which constitutes the South east Bay of Bengal and South west Arabian Sea coastal regions of India. Out of 19 distinct pigmented bacteria isolated only one strain showed potent inhibitory activity against bacterial pathogens. Based on morphological biochemical physiological characteristics and 16s rRNA gene sequencing it was conformed that the strain belonged to the genus Exiguobacterium sp. The pigment was extracted using diethyl ether and subjected to preparative HPLC for purification. Purified pigment exhibited antagonism towards Escherichia coli Staphylococcus aureus Staphylococcus epidermis Pseudomonas sp Bacillus sp Proteus sp Klebseialla sp Shigella sp and Salmonella sp. In case of DPPH radical scavenging assay the pigment showed higher radical scavenging activity with IC50 value 51.38gmL. The UV absorbance profile indicated that the pigment was probably a derivative of carotenoids. GC-MS analysis revealed that the pigment may be interlinked with methyl ester group.