Microbial population and screening of predominant strains for petroleum biodegradation in freezing soils of Shenfu wastewater irrigation area

Microbial population and predominant strains for petroleum biodegradation were isolated and screened in freezing soils of Shenfu wastewater irrigation area with an irrigation history for more than 50 years.The results showed that the quantities of bacteria in the petroleum contaminated soil were about 100 times more than that in the non-contaminated soil,the quantities of fungus and ray fungus in the contaminated soil were also extensively more than that in the non-contaminated soil.17 bacteria strains and 11 fungus strains for petroleum biodegradation were screened from the contaminated soils.The petroleum biodegradation experiment represented that Bacillus 12~# and Penicilliam freguentans Westling 22~# had the highest capacity for petroleum removing,the removal rate of that was 30.54% and 34.21%,respectively.