Biodegradation of slop oil from a petrochemical industry and bioreclamation of slop oil contaminated soil.

Slop oil, i.e. waste oil from a petrochemical complex, contains at least 240 hydrocarbon components, of which 54% are from C5 to C11 and the rest from C12 to C23. Of 22 isolated bacterial cultures that were able to degrade slop oil, seven could each degrade about 40% of the slop oil, and a mixture of all seven could degrade ≤50% in liquid medium. Bioaugmentation of soil contaminated with slop oil with the mixed bacterial culture gave up to 70% degradation of slop oil after 30 days. This compares with 40% degradation without bioaugmentation. Bioaugmentation led to a significant increase in counts of bacteria able to degrade slop oil. Wheat sown on bioaugmented soil germinated and grew better than on non-augmented soil and led to increased degradation of slop oil (up to 80%). This indicates the potential of mixed culture for bioremediation.