Effect of yeast extract supplementation on halotolerant biosurfactant production kinetics coupled with degradation of petroleum crude oil by Acinetobacter baumannii OCB1 in marine environment

Abstract

The pressing priority is to uncover environmentally secure techniques for abolition of oil spills suited to Indian marine conditions as increase in fuel consumption and demand has resulted in enhanced petroleum crude oil (PCO) transfer via sea route. Acinetobacter baumannii OCB1, isolated from petroleum refinery effluent, when grown in sea water supplemented with PCO (1.0% v/v) and glucose (1.0 g/L) yielded high degradation of C8 hydrocarbons (69.69%). On adding yeast extract (0.05 g/L) it degraded C8–C14 hydrocarbons (3.55–17.48%). Degradation was facilitated by lipopeptide biosurfactant (BS) having needle like surface as depicted by LCMS and FESEM analysis. Yield was higher in presence of yeast extract while there was no significant difference in activity. BS showed excellent stability at wide range of pH, temperature, salinity and high emulsification of petroleum-based oils. BS production modelled by Leudeking Piret model was growth associated and mixed growth associated without and with yeast extract respectively.