Transformer oil degradation by an indigenous microflora isolated from a contaminated soil

In this study polychlorinated biphenyls (PCBs, mostly penta to heptachlorinated isomers) from transformer oil were degraded under aerobic conditions in liquid culture using a mixed culture isolated from a soil contaminated with polychlorinated biphenyls and other hydrocarbons. Microorganisms in the mixed culture were identified as Comamonas acidovorans, Acinetobacter calcoaceticus, Achromobacter sp., Pseudomonas sp., Flavobacterium devorans, Bacillus lentus, Bacillus mascerans and Bacillus thuringiensis. A fungus of the genus of Paecilomyces and one strain belonging to Actinomyces were partially identified. The mixed culture could remove 75% of PCBs (88% w/v in the transformer oil). Our results provide evidence that naturally occurring aerobic microorganisms in the soil have the potential to attack PCBs.