Biocatalytic lipoprotein bioamphiphile induced treatment of recalcitrant hydrocarbons in petroleum refinery oil sludge through transposon technology.

The present investigation employed transposon technology to enhance the degradation of recalcitrant petroleum hydrocarbons present in petroleum oil sludge by using biosurfactant hyper-producing strain Enterobacter xiangfangensis STP-3. Out of 2500 transposon induced mutants, mutants M 257 E.xiangfangensis and M 916 E.xiangfangensis hyper-produce biocatalytic lipoprotein biosurfactant by1.98 and 2.34 fold higher than wild-type strain. Transposon induced mutation also modified the amino acid composition which improved the hydrophobicity and thermal stability of the biosurfactants produced by mutants, compared to the wild-type biosurfactant. GC-MS and LC-MS-MS revealed that biosurfactants have pentameric lipid moiety and esterase as protein moiety. Increased biosurfactant hydrophobicity and yield by the mutants resulted in the enhanced bioavailability of petroleum hydrocarbons, thereby mutants M 257 E.xiangfangensis and M 916 E.xiangfangensis demonstrated better petroleum oil sludge degradation by 82% and 88% respectively, than wild-type (72%). Disrupted genes vgr G and pgm M in M257 E.xiangfangensis and M916 E.xiangfangensis respectively hyper-produce biosurfactant by competitive pathway inhibition and increased precursor availability mechanism. Hyper-production of biosurfactant was also validated by comparing the expression of biosynthetic genes ent E , ent F and est using qPCR. This is the first report on the application of transposon technology to hyper-produce biosurfactant for the effective bioremediation of hydrocarbon contaminated environments. [Display omitted] • A novel biocatalyst conjugated bioamphiphile is used for the treatment of oil sludge. • Transposon technology employed to improve the strain to overproduce bioamphiphile. • Improved strain produced highly efficient bioamphiphile with two-fold yield. • Mechanism behind the production of novel bio-amphiphile was hypothesised. • Achieved effective PHCs treatment with the intervention of novel amphiphile. [ABSTRACT FROM AUTHOR]