一株多环芳烃降解菌吉2及其降解能力

A PAH-degrading strain JI 2 and its biodegradation potential ability

从中原油田毛8区块油田采出液中分离得到一株多环芳烃(PAHs)降解菌吉2,根据形态观察、生理生化、16S r RNA基因、管家基因和DNA-DNA同源性分析判断,吉2属于一株Microbacterium新种。研究发现,该菌能在萘和芘为唯一碳源的无机盐培养基中生长,也能够降解萘、菲、蒽和芘的混合PAHs。7 d对这4种PAHs的降解率分别达到了61.4%、86.6%、69.9%和18.6%。吉2对原油有很好的降解及降黏作用,7 d原油的降解速率达到了134 mg·d-1,黏度降低了29.3%。傅里叶变换红外光谱、族组分和气相色谱-质谱分析显示吉2能够优先利用原油中含PAHs的芳香烃和胶质等组分,原油中萘系列、菲系列、噻吩系列、芴系列、-系列、C21-三芳甾醇、芘和苯并(a)芘的相对含量都有一定程度的降低。实验结果表明吉2具有修复PAHs和原油污染的水体或土壤环境的能力,为微生物修复PAHs污染和原油污染提供了一种可行的途径。

A PAH-degrading strain JI 2 was isolated from oilfield produced water in Mao 8 block of Zhongyuan Oilfield. According to analysis of morphological observation, physiological and biochemical test, 16S rRNA gene, house-keeping genes and DNA-DNA hybridization, JI 2 was considered to represent a novel species of the genus Microbacterium. The strain could not only grow in inorganic salt culture medium and utilize naphthalene and pyrene as the sole carbon source, but also degrade mixed naphthalene, phenanthrene, anthracene and pyrene. The four PAHs degradation rates could reach 61.4%, 86.6%, 69.9% and 18.6%, respectively after 7 d. The viscosity of crude oil treated with JI 2 decreased by 29.3% and degradation rate was 134 mg·d-1. Fourier transform infrared spectra, group composition and GC-MS analysis of the crude oil treated with JI 2 showed that the strain tended to utilize PAHs in aromatic hydrocarbons and resins in crude oil. The relative contents of naphthalene series, phenanthrenseries, thiophene series, fluorene series and chrysene series, C21-triaromatic steroid, pyrene, and benz（a）pyrene decreased after degradation. JI 2 had the capacity to remediate water and soil environment contaminated by PAHs and oil, and provided a feasible way for bioremediation of PAHs and oil pollution.