Used lubricating oil degradation and biosurfactant production by SC-9 consortia obtained from oil-contaminated soil

Consortia of used lubricating oil-degrading bacteria were isolated from oil-contaminated soil. The most active consortia in the assimilation of used lubricating oil were SC-9. This consortia contained four bacterial isolates based on culture-dependent technique. They were identified as Agrobacterium tumefaciens, Bacillus cereus, Chryseobacterium sp., and Sphingobacterium multivorum based on 16S rDNA sequence analysis. The SC-9 consortia showed 40.5% oil-degrading activity within 7 days. The addition of molasses to the liquid medium had a positive effect and there was an increase in the percentage of oil degradation and a greater in reduction surface tension. The ability of selected bacteria to degrade oil increased in a comparable trend as its biosurfactant production increased. Oil-degrading bacterial isolates that display substantial potential for production of biosurfactants can be applied in the bioremediation of soils contaminated with petroleum hydrocarbons.