Bioremediation of soil heavily contaminated with crude oil and its products: composition of the microbial consortium

Bioremediation, a process that utilizes the capability of microorganism to degrade toxic waste, is emerging as a promising technology for the treatment of soil and groundwater contamination. The technology is very effective in dealing with petroleum hydrocarbon contamination. The aim of this study was to examine the composition of the microbial consortium during the ex situ experiment of bioremediation of soil heavily contaminated with crude oil and its products from the Oil Refinery Pancevo, Serbia. After a 5.5-month experiment with biostimulation and bioventilation, the concentration of the total petroleum hydrocarbons (TPH) had been reduced from 29.80 to 3.29 g/kg (89 %). In soil, the dominant microorganism population comprised Gram-positive bacteria from actinomycete-Nocardia group. The microorganisms which decompose hydrocarbons were the dominant microbial population at the end of the process, with a share of more than 80 % (range 10(7) CFU/g). On the basis of the results, it was concluded that a stable microbial community had been formed after initial fluctuations.