典型油气藏上方甲烷氧化菌群的分子生物学解析

摘要

In this study, the community structure of aerobic methanotrophic communities were investigated at light hydrocarbon microseeps above a known oil band gas field in the Shengli Oilfield. Clone library analysis of the pmoA gene revealed major differences in the methanotrophic community composition between oil and gas fields and the surrounding soils. The relative abundance of methanotrophic Methylocystis and Methylosinus ( typeⅡ) in surrounding soils is obviously lower in oil and gas field soils than surrounding soils, ut the relative abundance of methanotrophic Methy-lococcus and Methylocaldum (type I) presents a reverse tread. Terminal restriction fragment length polymor-phism ( T-RFLP ) analysis confirmed that one distinct Methylococcus and Methylobacter-related group may dominate the community at hydrocarbon microseeps. The pmoA gene copy numbers determined by real time PCR also indicated that methane oxidizing microbial community anomalies above typical oil and gas reservoirs exist objectively.%以胜利油田典型油气藏为研究对象，原位提取土壤中的甲烷氧化微生物群落组成信息，明确了油气指示微生物类群。通过对油田、气田和背景区土壤的pmoA基因克隆文库分析发现，来自油气藏上方土壤与背景区土壤的甲烷氧化菌群结构的差异较大。背景区土壤的甲烷氧化Ⅱ型菌---甲基孢囊菌和甲基弯曲菌的相对丰度明显高于油气藏上方土壤，而甲烷氧化Ⅰ型菌---甲基球菌和甲基暖菌则显著减少，表明长期的油气微渗漏能使甲烷氧化微生物群落向Ⅰ型菌演替。 T-RFLP 多变量统计分析结果显示，经过地质历史时期的微量轻烃连续驯化，油气藏上方的甲烷氧化微生物群落发生了演替，甲基球菌和甲基杆菌可能是推动这种演替变化的关键种群。甲烷氧化pmoA基因的丰度在油气藏上方的异常可以用于预测下伏油气藏的存在。