Enrichment and Identification of Askarel oil (PCB blend) degrading bacteria enriched from landfill sites in Edo State, Nigeria

Abstract

Microbial degradation following aerobic biodegradation is one of the means used by microorganisms for the removal of persistent organic pollutants from the soil. Bacterial species namely: Pseudomonas, Micrococcus Arthrobacter and Acinetobacter capable of utilizing askarel oil (PCBs blend) were isolated from landfill soil samples from Uzogholo, Mgboaku and Auchi in Edo State of Nigeria. The isolation of these bacterial species followed an enrichment in minimal salt media were Askarel oil served as the sole carbon source. These bacterial isolates were characterized based on their cultural, morphological, biochemical characteristics and comparison with standard reference organisms. The potentials of these bacterial species to utilize askarel oil were assessed by measuring changes in the turbidity and pH of the enrichment medium containing varying concentrations of the Askarel oil. From the weekly results obtained, significant increases in the mean turbidity ranged between (0.065- 0.371) and decreases in mean pH ranged between (6.15- 3.55) for the 21 days incubation period. Some of the bacterial organisms exhibited remarkable utilization of askarel oil at different concentrations in 15μL and 20μL of the askarel minimal salt medium. From these findings, the bacterial species of remarkable potential can be isolated, re-engineered via biotechnology or bioaugmentation for effective remediation of landfill sites polluted with Polychlorinated biphenyls compounds and its derivatives in Nigeria.