一株菲降解菌的分离鉴定及其降解条件研究

Isolation,identification and degradation conditions of a phenanthrene-degrading bacterium

以菲为研究对象,从克拉玛依稠油污染土壤中筛选到1株对菲具有较好降解效果的菌株JZ3-21。通过形态观察、生理生化指标及16S rDNA序列分析对该菌株进行了鉴定。该株菌的16S rDNA序列与Pseudomonas属的相似性达99%,结合分离菌株的形态、生理生化特征和16S rDNA基因序列的分析结果,初步鉴定该菌株为恶臭假单胞菌(Pseudomonas putida.)。对其降解条件进行了研究,结果表明:在40℃,pH 8.0,接种量为1.5%的条件下,菌株对初始质量浓度为100 mg.L-1的菲在64 h内的降解率高达94.2%。该菌对高质量浓度菲有较好的耐受性,其最高耐受质量浓度可达2 000 mg.L-1。

Phenanthrene was used as target to study the biodegradation effectiveness.A phenanthrene-degrading strain JZ3-21 with better activity was isolated from soil contaminated by heavy oil from Karamay of Xinjiang Oilfield.The strain JZ3-21 was identified according to its morphological,physiological,biochemical,and 16S rDNA sequence characteristics.The sequence similarity of 16S rDNA between JZ3-21 and Pseudomonas sp.was up to 99%.The results indicated the phenanthrene-degrading bacterium belonged to the Pseudomonas putida.Moreover,the biochemical degradation of phenanthrene was further studied.Under the optimum conditions of 40 ℃,pH 8.0,inoculum concentration（1.5%） and phenanthrene mass concentration of 100 mg·L-1,the degradation rate of phenanthrene reached 94.2% in 64 h.The strain has a good tolerance to high concentrations of the phenanthrene,and its maximum tolerated concentration can reach 2000 mg·L-1.