一株高效降解芘的细菌分离、鉴定及其降解效果

摘要：【目的】获得高效降解高分子量多环芳烃的细菌，并研究其对多环芳烃的降解能力。【方法】利用富集培养和芘升华平板方法，从焦化厂污染土壤中分离多环芳烃降解细菌，对分离菌株通过形态特征、16S rRNA基因和gyrb基因序列相似性分析进行鉴定，并研究该菌对高分子量多环芳烃（HMW-PAHs）的降解效果。【结果】筛选到一株能以芘、苯并蒽、屈、苯并芘、茚并芘、苯并苝、荧恩为碳源和能源生长并降解这些底物的菌株HBS1，该菌株的16S rRNA基因和gyrb基因序列与Gordonia amicalis的相应基因的相似

Isolation and identification of a pyrene-degrading bacterial strain from contaminated soil and its degrading efficiency

Abstract:[Objective] The aim of this study was to isolate efficient high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs) degrading bacterial strains, and to study their degradation potential.[Methods] We used sublimation method to enrich and isolate the degrading bacteria from coking plant samples. Morphological properties, the sequence homology of 16S rRNA and gyrb genes were used to identify the isolated strains. GC-MS was used to analyze the degradation potential against some HMW-PAHs. [Results] A HMW-PAHs degrading bacterium, HBS1, was obtained. Strain HBS1 could use several HMW-PAHs such as pyrene,benzoanthracene,benzopyrene,chyrsene,indeno[1,2,3-cd]pyrene,benzo[g,h,i]perylene and fluoranthene as sole carbon source for growth. Strain HBS1 was identified as Gordonia sp.. Based on the high sequence similarities (more than 99%) of both 16S rRNA gene and gyrb gene to those of Gordonia amicalis. When the initial concentration of pyrene was 50 mg/L, strain HBS1 could consume 97% of the pyrene in 17 days. One fragment of the dioxygenase gene was obtained by PCR with size about 300 bp, which was closest to the counterpart from Mycobacterium sp. with 93.8% similarity. [Conclusion] We isolated a strain HBS1 from seriously PAHs-polluted soils and identified it belong to Gordonia sp.. The isolate got a great degradation potential of high-molecular weight polycyclic aromatic hydrocarbons.