Screening and identification of effective microorganisms for oil-contaminated soil bioremediation

Based on the bioremediation characteristics of oil-contaminated soil, efficient oil-degrading bacteria from soils contaminated by oil at varied levels were screened and identified. DGGE was used to analyze the combination of bacteria in oil-contaminated soil. At last, research scheme of bioremediation reagent was suggested. The results showed that: main efficient oil-degrading bacteria include micrococcus, arthrobacter, bacillus, acaligenes, acetobacter, flavobacterium, aspergillus, aspergillus versicolor, penicillium chrysogenum, penicillium freguentans westling, fusarium lk. cephaesosp orium oud, tichoderma viride and aureobasidium. Fungi were more efficient than bacilli in degrading oils and were the main function microorganisms in bioremediation of oil-contaminated soil. Microorganisms' activities were affected by soil characteristics. Oil of proper level promoted the growth of efficient microorganisms while over level oil restrained the growth of microorganisms. It also suggested that Aspergillus, Fusarium Lk. were more efficient in bioremediation of light-or middle-level-contaminated soil, while Aureobasidium were more efficient for heavy contaminated soil. Bioremediation reagent was suggested to include efficient oil-degrading microorganisms, microbial nutriments, biosurfactant and soil activating reagents.