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

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.