大港油田石油降解菌的选育及其特性探究

Isolation of Oil-Degrading Bacteria from Dagang Oil Field and Their Degradation Characteristics

从大港油田储油罐和采油井附近的受污染土壤中筛选高效石油降解菌,研究其生长特性,并进行降解机理的初步研究。利用石油为唯一碳源的培养基筛选优势降解菌株。经16SrDNA基因序列分析及分子系统发育树的构建结果,确定菌株的种属。通过产表面活性剂能力测定、菌群数变化分析、降解前后原油成分鉴定以及降解相关酶活测定,研究了混合菌群对石油的降解机理。结果表明,混合菌群d-8/d-9/d-10具有最优降解力(30℃,180r·min-1,7d内可降解73.74%原油),其中d-8在降解过程中菌数增加显著,被鉴定为大肠埃希菌属,其降解后的原油仅检测到C17和C18两种成分且含量明显降低,d-8/d-9主要降解短链烷烃,d-10产生表面活性剂,促进油水相容,但其降解能力不及d-8/d-9,为辅助降解菌株。d-8/d-9/d-10混合菌群对石油表现出较高的耐受力,具有一定的环境修复潜力。

The soil samples were collected near the storage tanks and petroleum contaminated wells on Dagang oil field, and strain screening to explore the growth characteristics and degradation ability was studied. The medium with crude oil as the sole carbon source was used to obtain the degrading strains. Strain identification was studied by 16S rRNA gene sequence analysis and the phylogenetic tree. To investigate the oil degradation ability by the mixed strains, the components of oil before and after degradation were analyzed by the gas chromatography-mass spectrometry （GC- MS） analysis. Finally, the activity of the enzymes related to the degradation was determined. The results indicated that the strain combination of d-8, d-9 and d-10 showed the best ability to degrade oil with the rate of 73.74%. The d-8 was the key strain for oil degradation, d-9 ability was slightly lower, and d-10 produced bio-surfactant to promote water solubility. Three strains （d-8, d-9 and d-10） collaborated to achieve oil degradation, showing certain potential for environmental remediation.