Microbial-induced biosurfactant-mediated biocatalytic approach for the bioremediation of simulated marine oil spill

Abstract

Marine crude oil spill is the most alarming environmental issue and the dreadful instance of petroleum hydrocarbon pollution around the world. Successful remediation of these toxic pollutants demands for the ample production of biosurfactant and biocatalysts by the native hydrocarbon-degrading microbes. The main focus of this investigation is to determine the potential of a halo-tolerant and biosurfactant-producing hydrocarbonoclastic bacterium, Enterobacter hormaechei, for the effective bioremediation of marine oil spill. The strain had the ability to produce biosurfactant with excellent surface and emulsification activities along with biocatalysts. The activity of the extracellular enzymes such as lipase and laccase was found to be 160 U/ml and 38 U/ml, respectively, whereas the intracellular enzymes like alkane hydroxylase, alcohol dehydrogenase and esterase showed the corresponding activities of 48 U/ml, 86 U/ml and 102 U/ml. Overall, E. hormaechei could be able to degrade nearly 85% of petroleum hydrocarbons present in crude oil within 10 days of incubation. The biosurfactant was characterized to be an anionic, high molecular weight (48 kDa) lipoprotein-type biosurfactant. The biosurfactant was further characterized by Fourier transform infrared spectroscopy. The E. hormaechei was employed for the treatment of simulated marine oil spill and the degradation followed pseudo-second-order kinetics with rate constant k2 0.2775 and R2 0.9923. The crude oil degradation was confirmed by gas chromatography–mass spectrometry. The study suggested that the E. hormaechei is a potential biosurfactant and biocatalysts producer with the effective management of accidental marine oil spills.