木里地区水合物轻烃微渗漏微生物群落及烃氧化菌响应特征研究

摘要

为了研究水合物轻烃微渗漏对近地表微生物群落的影响作用,采用二代测序技术,对木里冻土区见水合物钻孔DK1、DK9和无水合物孔DK6附近土壤中的微生物群落进行了研究.相对于无水合物钻孔DK6,水合物钻孔的微生物群落结构发生了改变,尤其是烃氧化微生物在水合物钻孔具有明显的数量优势;水合物钻孔DK1以烷烃氧化菌为优势烃氧化菌群,水合物钻孔DK9以甲烷氧化菌为优势烃氧化菌群,这与DK1和DK9的水合物气体组分差异表现一致,无水合物钻孔DK9则无明显优势烃氧化菌群.以丁醇为唯一碳源的选择培养也得到了一批常见的烃氧化菌,这些可培养烃氧化菌可用于水合物相关烃类微渗漏的指示.上述以烃氧化菌群为代表的微生物群落及可培养烃氧化菌对木里天然气水合物响应特征的研究说明了基于轻烃微渗漏模型的微生物勘探技术应用于木里天然气水合物勘探具有可行性.%Next generation sequencing was used in the study of near-surface microbial communities located in gas hydrate well DK1,DK9 and dry well DK6,Muli permafrost zone,to discover the influence of light hydrocarbon microseepage on near-surface microbial community.Compared with dry well DK6,microbial communities in gas hydrate wells changed,especially the hydrocarbon oxidizing microorganisms showed more abundance in gas hydrate well.Furthermore,the predominant hydrocarbon oxidizing microorganisms in gas hydrate well DK1 were alkane oxidizing,and those in well DK9 were methane oxidizing,in accordance with the different gas components in the gas hydrate wells.On the other hand,there were no predominant oxidizing microorganisms in dry well DK6.Besides,selective culture using butanol as the only carbon source also got a number of popular hydrocarbon oxidizing microorganisms,which could be used as the indicators of light hydrocarbon microseepage related to gas hydrate.Above all,the microbial communities,especially both uncultured and cultured hydrocarbon oxidizing microorganisms,showed detectable response to the gas hydrate underground,confirming the feasibility of microseepage based microbial exploration technology used in Muli permafrost gas hydrate survey.