盐碱土壤PAHs降解菌的筛选鉴定及其降解特性

Isolation,identification and degradation characteristics of a PAHs-degrading bacteria from salt-alkaline soil

采用富集培养的方法,从天津大港油田PAHs污染盐碱化土壤中分离出一株能以菲、芘为唯一碳源和能源的优势菌TJB5。经形态观察和16S rDNA序列分析结果表明,该菌株为成团泛菌(Pantoea agglomerans)。采用液体培养的方法,研究了pH、盐度、菲芘的初始浓度对TJB5菌株降解菲芘效果的影响,确定了最佳降解条件。结果表明,该菌对菲、芘的降解具有较广泛的pH、盐度范围和良好的降解效果。在菲、芘浓度分别为50 mg/L、pH 6.8-9.5、盐度2%-3%、温度30°C条件下,接种15 d后菲降解率在93.3%以上,芘降解率在20%以上。

A predominant PAHs-degrading strain TJB5 was isolated from PAHs-contaminated salt-alkaline soil in Dagang Oilfield of Tianjin,which can use phenanthrene and pyrene as sole carbon source for growth in the selective culture medium.Strain TJB5 was identified as Pantoea agglomerans according to the results of morphology and the phyogenetical analyses of 16S rDNA sequence.The effect of initial concentration of phenanthrene and pyrene,inoculating pH and salinity on degradation efficiencies was investigated.The optimal degradations were determined.The results indicated that the degrading characteristics of the strain were fine.More than 93.3% of phenanthrene and 20% of pyrene in the medium were degraded in the liquid medium with 50 mg/L phenanthrene and pyrene,pH 6.8-9.5 and salinity ranging from 2% to 3% after 15 days at 30 °C.