IMPROVEMENT OF THE EFFICIENCY OF OIL-CONTAMINED SOILS REMEDIATION IN THE NATURAL CONDITIONS OF THE NORTH TOMSK REGION AND THE NEARBY REGIONS BY INDIGENOUS MICROORGANISMS APPLICATION

Abstract

The relevance of the study. The largest anthropogenic pressure associated with the exploitation of natural resources in the Tomsk region falls on the oil and gas industry. Geoecological analysis of the territory showed that the northern administrative regions are the most vulnerable areas, while the main factor in oil pollution of the soil is pipeline accidents. Bioremediation is a low-cost and environmentally friendly method of restoring contaminated areas. An effective approach to the bioremediation of oil-contaminated soils is isolation indigenous hydrocarbon-degrading microorganisms and creation biological products based on the strains. The main aim of the study is developing an industrial consortium based on indigenous hydrocarbon-oxidizing bacteria from soils of the North Tomsk Region and evaluating its effectiveness for bioremediation of oil-contaminated soils. Objects and methods. Cultures of indigenous hydrocarbon-oxidizing microorganisms were obtained under selective conditions from the crude oil contaminated soil sample, Soviet oil field, Tomsk Region. Isolated strains were identified using molecular genetic methods based on the analysis of 16S rRNA gene sequences. The physiological and biochemical properties of the isolates were studied by standard methods, and the morphology of the cells was studied microscopically. To assess the effectiveness of a biological product based on the selected strain, field tests were carried out in oil-contaminated areas. Quantitative chemical analysis for the total content of petroleum products in the soil was performed by fluorimetric method. Results. During the study, three novel strains of hydrocarbon-oxidizing bacteria belonging to the genera Acinetobacter and Oleomonas were isolated from oil-contaminated soils in the Tomsk Region and characterized. Indigenous microorganisms are characterized by reduced optimums of temperature and pH in comparison with type strains. Based on the identified microorganisms, a commercial biological product «Aborigen» was developed for bioremediation of oil-contaminated soils and wetlands. The experimental restoration of oil-contaminated soils with the help of a preparation of indigenous microorganisms-destructors has significantly reduced the time compared to self-restoration of soil cover during natural processes. Field tests showed high efficiency of oil destruction under the influence of a biological product – on average, in eight experimental sites, the total content of oil products in the soil was reduced 12,4 times in three months.

Keywords

• crude oil contamination of soil
• bioremediation
• indigenous microorganisms
• microbial consortia
• environmental pollution
• oil and gas industry