Isolation and screening of marine bacterial strains for Biosurfactant production

Surfactants are the amphiphilic compounds which reduce surface tension between molecules. In the past decades, such compounds were reported to be produced on the surface of living organisms, especially microorganisms and are termed biosurfactants. These compounds are used for a variety of industrial purposes because of their varied advantages such as biodegradability, renewability, functionality under extreme conditions etc. The main areas of usage include oil and petroleum industries, pollutant site remediation, detergent formulations, cosmetics, food additives, pharmaceutical industry etc. Though these are promising compounds, the large-scale industrial production is difficult due to material costs, processing costs and manufacturing output. The work is done to identify and isolate microorganisms from marine system with a view to carry out in depth studies on the activity of the isolated strains and ways by which these strains can be used as economically viable sources for biosurfactants. Twelve strains were isolated from the marine water sample. Eight strains showed growth in oil supplemented medium. Four of these strains showed slightly higher growth than the rest of isolates. Emulsification index was calculated for these strains and two strains, Tb1 and Tb3 showed maximum emulsion index in both kerosene and diesel. But none of the tested strains showed glycolipid production.