一株菲降解菌的分离、鉴定及最佳培养条件的优化

从石油污染场地分离到一株可降解菲的菌株SP 3，经生理生化鉴定和16S rDNA序列对比分析，初步鉴定该菌株为分枝杆菌（Mycobacterium sp.），该菌能够以菲为唯一碳源，在菲浓度为100 μg/mL的无机盐培养基中，28 ℃摇床培养7 d降解率达到了99%以上。对该菌进行了最佳发酵培养基及培养条件的优化研究，其最佳培养基配方为淀粉1%、牛肉膏1%、Na2HPO4 0.2%、NaH2PO4 0.2%，并通过单因素实验法确定了最佳培养条件为温度30 ℃，初始pH =7.5，培养时间12 h。

Isolation,identification and optimization of growth conditions of a strain of phenanthrene degrading bacteria

A phenanthrene degradable strain SP 3 was isolated from petrol contaminated soil. It was roughly identified as Mycobacterium sp.through physiological and biochemical identification and contrast analysis of 16S rDNA sequences. Phenanthrene could be served as its unique carbon source.The degradation rate is more than 99% in such conditions as mineral salt medium of phenanthrene concentration of 100 μg/mL,shaking culture of 28 ℃ and 7 days. We discovered that optimal culture medium of strain SP 3 included starch of 1%, beef extract of 1%,Na2HPO4 of 0.2%and NaH2PO4 of 0.2%. We determined its optimum culture conditions of temperature of 30 ℃, initial pH of 7.5 and culture time of 12 h through single factor experiment.