大港孔店油田水驱油藏微生物群落的分子分析

通过多聚酶链式反应温度梯度凝胶电泳（PCRTGGE）和构建16S rRNA基因克隆文库两种方法对比研究了大港油田孔二北断块注水井和采油井的微生物群落结构。16S rDNA V3区PCR扩增产物的TGGE图谱分析表明，这两个油井的微生物群落结构差异很大。注水井样品的TGGE图谱中有6条主要条带，而采油井样品中只有一个条带占绝对优势。同时，建立了两个样品的16S rRNA基因克隆文库，从中分别挑选了108和50个克隆进行限制性酶切片段长度多样性分析（ARDRA）。注水井样品有33个操作分类单元（OUT），其中6个OUT是优势类型；而采油井样品只有8个OUT，有1个OUT在文库中占绝对优势。克隆文库和TGGE的研究结果一致，均表明注水井样品的微生物多样性比采油井丰富很多。每个OUT的代表克隆序列分析结果表明，注水井样品中的细菌主要属于α、β、γ变形菌纲和放线菌纲，尤其是红细菌亚纲（47%）。采油井样品的细菌主要属于α、β、γ变形菌纲，尤其是假单胞菌属（62%）。油藏微生物多样性的分子分析可为开展微生物采油技术研究奠定基础。

Molecular analysis of the microbial communities of the Dagang Kongdian flooding bed oilfield

Both PCR-TGGE (temperature gradient gel electrophoresis, TGGE) and 16S rRNA gene clone library construction were used to comparatively analyze the microbial communities of a water injection well (WW) and an oil well (OW) in Dagang oilfield. TGGE analysis of the PCR amplified 16S rDNA V3 region products showed great difference between these two microbial communities. Six major bands were detected in the TGGE profile of the WW sample, while only one predominant band in the OW sample was found. Two 16S rRNA gene clone libraries were also constructed, and 108 and 50 clones were selected from the WW and OW library respectively for amplified ribosomal DNA restriction analysis (ARDRA). 33 taxanomic operational units (OTUs) were found in the WW library with 6 major OTUs, while only 8 OTUs were found in the OW library with one OTU predominant. The results of TGGE and clone library profiling analysis both indicated that microbial community of the WW had higher diversity than the OW. Sequence analysis of the representative clone of each OTU showed that most bacteria of the WW were affiliated with alpha, beta, and gamma Proteobacteria and Actinobacteria, especially Rhodobacter (47%). Most bacteria of the OW were affiliated with alpha, beta, and gamma Proteobacteria, especially Pseudomonas (62%). Molecular analysis of the microbial diversity in oilfield provides foundation for better application of MEOR (Microbial Enhanced Oil Recovery).