菲高效降解菌的筛选及其降解中间产物分析

Isolation of Phenanthrene-degrading Microorganisms and Analysis of Metabolites of Phenanthrene

生物降解是多环芳烃从环境中去除的主要途径,而获得高效降解多环芳烃的优势微生物是当前进行多环芳烃污染生态系统修复的关键所在。本研究采用水-硅油双相体系从污染土壤中富集到3个以菲为惟一碳源和能源的混合菌系GY2、GS3和GM2,这3种混合菌在72h内对初始浓度为100mg·L-1菲的降解率分别达到99.9%、99.9%和91.9%。从GY2中分离得到高效降解菲的菌株GY2B,48h对菲的降解率达到99.1%。经UV-Vis和GC-MS分析发现,混合菌GY2降解菲的中间代谢产物主要有1-羟基-2-萘酸和1-萘酚,纯菌GY2B降解菲的中间代谢产物主要有水杨酸、1-萘酚和1-羟基-2-萘酸。

Microbial degradation has been suggested as the best way to remove polyeyclic aromatic hydrocarbons （PAHs） from contaminated environment. Therefore, this study aims to evaluate the potential of phenanthrene-degrading microorganisms, isolated from the PAHs contaminated soil of arable land, oil gas plant, and wood preservation plant. The results of such an evaluation allowed the selection of those microorganisms with ability to degrade phenanthrene, added as the only carbon and energy source to a medium. Degrading phenanthrene microorganisms in 3 mixed cultures （GY2 represented culture of microorganism from the oil gas plant soil, GS3 represented that from the arable land and GM2 represented that from the word＇preservation plant） were enriched by the water-silicon oil biphasie system. In the mineral salts medium under initial phenanthrene concentration of 100 mg·L^-1 the removal rates of phenanthrene were 99.9%, 99.9% and 91.9%, respectively after 72 hours. One preponderant bacterial strain, isolated from mixed GY2 culture and obtained from pure GY2B culture, can degrade 99.1% of the phenanthrene in the same condition after 48 hours. 1-hydroxy-2-naphthoic acid and 1-naphthol were identified as the major metabolites in the mixed GY2 culture and pure GY2B culture. Additional, salicylic acid was detected as a metabolite in pure GY2B culture.