[Isolation, identification, and degrading characteristics of a high-efficient pyrene-degrading bacterial strain]

By using selective enrichment culture with pyrene as the sole carbon source, a pyrene-degrading bacterial strain ZQ5 was isolated from the oil-contaminated soil in Shenfu Irrigation Area. The strain was identified as Stenotrophomonas sp., based on its morphological, physiological, and biochemical characteristics, and similarity identification of 16S rDNA sequence. The pyrene-degrading characteristics and the effects of culture condition on the degrading efficiency of the strain were investigated by shaking flask culture. After shaking culture with the initial concentration of pyrene being 100 mg x L(-1) at 30 degrees C for 10 days, the degradation rate of pyrene was 91.2%. Adding 100 mg x L(-1) of alicylic acid into culture medium could enhance the degrading efficiency of the strain. For the degradation of pyrene by ZQ5, the optimal medium pH was 7-8, and the optimal salt concentration was lower than 2%.