Production and characterization of lipopeptide biosurfactant producing Paenibacillus sp. D9 and its biodegradation of diesel fuel

The current research aimed at analyzing the biodegradation efficiency of a potent biosurfactant producing Paenibacillus sp. D9, along with the characterization of the surface-active compound produced during diesel fuel biodegradation. The biosurfactant production by Paenibacillus sp. D9 was evaluated using diesel fuel as culture medium, subsequently analyzed for its structural characteristics using different methods and thus determining the biodegradation utilization. This strain showed wide cell surface hydrophobicity against varieties of hydrocarbon substrate tested. Paenibacillus sp. D9 displayed higher hydrophobicity to the long-chain hydrocarbons mixtures tested such as 71.5% diesel fuel, 70.0% engine oil and 76.0% n-paraffin. The optimum condition for biosurfactant synthesis was obtained in a medium containing 10% (v/v) diesel fuel with a production yield of 4.7 g/L. The resultant biosurfactant reduced surface tension from 71.4 to 30.1 mN/m against carbon source utilized. The critical micelle concentration value of the biosurfactant was 200 mg/L with emulsification efficiencies against a wide range of hydrophobic pollutants. With different physiochemical and analytical methods, the study demonstrated that the genus Paenibacillus produced a low molecular weight lipopeptide biosurfactant. Its emulsifying ability further supports its potential use in environmental and biotechnological applications.