Response surface methodology was applied to optimize the production of biosurfactants from Bacillus mojavensis I4 using Box-Behnken design with four variables. The optimal variable combination was 3% of glucose as carbon source, 0.6% of glutamic acid as nitrogen source, temperature of 35 °C and 10 g/l of NaCl which yielded to an optimal production of 4.12 g/l. Compositional analysis and FTIR spectrum revealed that the extracted biosurfactants was a lipopeptides. The biosurfactants achieved a critical micelle concentration value of 100 mg/l. Moreover, the extracted biosurfactants were effective at recovering up to 89.2% of motor oil from sand beach and achieved a dispersion rate of 78% of the initial diameter of the oil. These findings suggested the potential use of I4 biosurfactants in the oil industry.
Keywords: Bacillus mojavensis; Biosurfactants; Oil recovery; Production optimization.