一株菲降解细菌的分离及其特性

利用平板熏蒸和双氧加合酶活性测定的方法 ,从大庆油田水体中筛选出 1株对菲具有降解活性的细菌 ,Phx1.在LB培养基中 ,能将浓度为 10 0 μg/mL的菲在 2 4h内完全降解 .与无机盐培养基相比 ,LB和牛肉膏蛋白胨培养基能促进此菌对菲的降解 ,尤其能促进对中间产物的进一步转化 .经质粒消除证明 ,Phx1具有 2个质粒 ,且较大的 1个对菲的降解是必须的 .通过对其形态、生理生化特性 ,16SrDNA序列分析 ,鉴定Phx1为土壤杆菌属细菌 ,其 16SrDNA序列与Agrobacterium tumefaciensUP 3、Agrobacterium albertimagni的相似性最高 ,分别达到 97 8%和 96 6 % ,但对向日葵的致瘤实验为阴性 .

Screening for Phenanthrene-Degrading Bacteria and Its Characteristics

One bacterial strain, designated as Phx1, was isolated from Daqing oil-field with the method of sublimate-plate and determination of dioxygenase activity. Phxl can degrade phenanthrene (100microg/mL, in LB media) completely in 24 h. Compared to MSM, LB and broth media can accelerate the phenanthrene degradation, promote the degradation of intermediates especially. With the method of plasmid elimination, it was proved that the genes encoding for degradation of phenanthrene locate on the larger one of the two plasmids. According to morphological and physio-biochemical characteristics, Phxl was identified as Agrobacterium sp. and was probably a new species of the genus Agrobacterium due to its 16S rDNA sequence which has the similarities of 97.8 % and 96.6% to Agrobacterium tumefaciens UP-3 and Agrobacterium albertimagni respectively.