采油废水厌氧处理系统的微生物群落特征

为了深入认识石油烃的厌氧降解过程,利用分子生物学技术分析了大庆油田采油废水处理系统厌氧池和进水中的微生物群落特征。基于DGGE和克隆文库的分析结果均表明,厌氧生物膜中存在的古菌源自于采油废水。厌氧生物膜和采油废水中的古菌主要是产甲烷菌,包括嗜甲基的Methanomethylovorans thermophila和利用氢和甲酸的Methanolinea tarda。值得注意的是,氢营养型的M.tarda在厌氧生物膜中得到了富集。进水和厌氧生物膜中的细菌群落结构明显不同。进水中的主要细菌类群为Epsilonproteobacteria,而生物膜中的主要类群为Nitrospira和Deltaproteobacteria。在厌氧生物膜中发现许多与产甲烷古菌(尤其是氢营养型产甲烷菌)协同降解石油烃类物质的细菌相关克隆:其中一个克隆与Syntrophus具有较高的同源性,该类菌是产甲烷菌介导的厌氧烃降解微生物区系中的关键细菌;许多Deltaproteobacteria克隆属于group TA类群,该类群细菌主要参与芳香族化合物产甲烷菌介导的厌氧降解过程。这些结果表明,在大庆油田采油废水厌氧处理系统中已经建立起由产甲烷菌所介导的厌氧石油烃降解的微生物区系。

Characteristics of microbial community in anaerobic produced water treatment system

Microbial characteristics in the anaerobic tank of a full-scale produced water treatment plant capable of anaerobic hydrocarbon removal were analyzed and compared to those in the influent produced water using cultivation-independent molecular methods. Both the DGGE and cloning analysis indicated that the methanogens in the anaerobic biofilm was derived from the influent produced water. It is found that the archaeal community in the anaerobic tank and the produced wastewater was mainly composed of methanogens, including the Methanomethylovorans thermophila and Methanolinea tarda. It had abundant hydrogen-utilizing M.tarda in the anaerobic biofilm. But the bacterial community structure in the produced water was obviously different from that in the anaerobic biofilm. The main bacterial population in the influent was Epsilonproteobacteria while it was Nitrospira and Deltaproteobacteria in the anaerobic biofilm. Notably, many syntrophic bacteria-related clones were found among the Deltaproteobacteria. One Deltaproteobacteria clone was related to Syntrophus sp., which is commonly found in methanogenic hydrocarbon-degrading consortia. A number of Deltaproteobacteria clones were assigned to the clone cluster group TA, members of which predominate in various methanogenic consortia that degrade aromatic compounds. These results suggested that it exist such kind of microbial community related to the anaerobic degradation of petroleum hydrocarbon mediated by the methanogens in the anaerobic wastewater treatment system in Daqing Oilfield.