Synergistic Capability of Bacterial-fungal Co-culture to Degrade Drill Cutting Hydrocarbon

Abstract

Petroleum is a complex mixture of hydrocarbons. No single species of microorganisms is able to degrade all components of the petroleum. Mutually beneficial interaction of microorganisms in the form of a consortium is required during the process of oil degradation. One form of mutually beneficial interaction between fungi and bacteria is biofilm formed by bacteria on fungal surface. The formation of bacterial biofilm on fungal surface was reported to increase the synergistic action of the two microorganisms in destroying certain complex compounds. This work was aimed to assess the capacity of hydrocarbon degrading-bacterial biofilm on the surface of hydrocarbon degrading-fungal surface to degrade hydrocarbons derived from drill cuttings. The hydrocarbon degrading-soil bacteria and fungi were isolated from different area in Yogyakarta, Indonesia after enrichment. The ability of bacteria to form biofilm on the surface of fungal hyphae was examined under light microscope with 1000x magnification after the addition of lactophenol. The effect of microbial amendment in the form of biofilm, in comparison with the planktonic culture, on degradation of hydrocarbons derived from drill cuttings were assessed by measuring the extractable petroleum hydrocarbon. The results showed that co-culture between fungi and bacteria which one among them or both of them have low ability to degrade hydrocarbon may significantly improve their ability and the ability of the co-culture to degrade hydrocarbon has no relationship with the ability of the bacteria to form biofilm on the surface of the fungal hyphae.