Studies on the bioemulsifier production by a bacterial isolate

Bioemulsifiers have gained a lot of importance in biodegradation, bioremediation, medical, pharmaceutical and food industries due to their non-toxicity. In the present study bacteria producing bioemulsifier were isolated from mangroves and saltpans on mineral salt medium (MSS) containing crude oil as sole carbon source. Amongst the 19 isolates picked up to screen for bioemulsification activity, 9 isolates showed potential bioemulsification activities which were in the range of 2.0-45.5 % for pellets while 1.7-56.5% for supernatants. Two isolates MS-3 and MS-18 that showed the highest Emulsification index with supernatant were selected and identified based on biochemical characteristics as Aeromonas (MS-3) and Vibrio (MS-18) species. The isolate MS-3 was selected for detailed studies. The bioemulsifier was isolated, purified and characterised using TLC, FTIR and found to be glycolipid in nature. The critical micelle concentration (CMC) of the present emulsifier was found to be 12 mg/ ml with xylene as the hydrocarbon.