多环芳烃降解菌筛选及其降解特性

Isolation and characteristics of PAHs-degrading strains.

通过选择性富集培养,从辽河油田稠油污染土壤4号土样中,获得了能以高浓度菲(2000 mg·L-1)为唯一碳源和能源快速生长的优势菌系和优良菌株ZL5.16S rDNA核苷酸序列分析表明,ZL5菌株归类于鞘氨醇单胞菌属.分得的菌系和菌株有较强的降解菲能力,120 h混合菌系降解了投加菲的95.28％,菌株降解了69.24％,但它们对芘的降解能力均较低.外加碳源葡萄糖可提高菌系和菌株的菲、芘降解能力,加量多,提高幅度大,但超过一定量,降解速率开始下降,表现出抑制效应.所以,应用时需控制适宜的浓度.

The predominant indigenous microbial population and the strain ZL5 PAHS-degrading were obtained by selective enrichment culture from Liaohe viscous oil-contaminated field. The sequence analysis of 16s rDNA showed that strain ZL5 belonged to Sphingomonas sp. The microbial population and the strain could degrade phenanthrene well. 95.28% and 69.24% of phenanthrene in the medium were degraded in 120hrs. However, the degradation of pyrene by the microbial population or by the strain was low. The degradation rate of phenanthrene or pyrene by the microbial population or the strain was greatly increased while glucose was used as an added substrate. The effect was closely related to the amount of glucose. If the concentration were too high, glucose would show inhibition effect on the degradation of PAHs. Therefore, it was necessary to control the amount of glucose while using glucose as an added substrate to increase degradation of phenanthrene or pyrene.