Development of Microbial Consortium for Bioremediation of Oil-Contaminated Soils in the Middle Ob Region

Hydrocarbon-decomposing microorganisms identified as representatives of the genera Pseudomonas, Rhodococcus, Acinetobacter, Kocuria, Raoultella, and Candida have been isolated from the oil-contaminated soil samples of the Middle Ob region. They have been screened for the ability to decompose various classes of hydrocarbons in a wide temperature range (6–37°C), in acid media (up to pH 4), and at increased salinity (up to 3%), for the ability to produce biosurfactants, and for the presence of genes encoding enzymes responsible for hydrocarbon decomposition. A microbial consortium has been suggested as the basis of a biological preparation for bioremediation of oil-contaminated soils in the Middle Ob region, including strains of Candida fluviatilis 24p-51, Rhodococcus erythropolis 24-44, Acinetobacter calcoaceticus 7-43, and Pseudomonas extremaustralis 7-31. The modes of cultivation and lyophilization of biomass have been determined for these microorganisms. The efficiency of degradation of oil hydrocarbons by the developed microbial consortium has been evaluated in laboratory model systems. The degree of oil degradation by the microbial consortium in the liquid mineral medium was 56%; in the model soil, 22% in 10 days at 24°C.