基于生物进化的油藏环境施氏假单胞菌采油功能研究

Microbial communities monitored during Microbial Enhanced Oil Recovery（MEOR）oil field trials by our research group revealed that Pseudomonas stutzeri was a main stimulated species; In addition, high diversity of P. stutzeri was observed in samples from oil reservoirs based on 16S rRNA gene sequences, new genomovars of P. stutzeri habiting in oil reservoirs were proposed。In this study, considering the relationships between P. stutzeri and extreme natural environments of producing oil reservoirs, we are carrying out further studies on genomovar distribution and functional genes of P. stutzeri during MEOR field trials based on ropD gene clone library, strains isolation, metagenome sequencing of oil/water samples and isolated strains, to interpret the acquiring mechanisms of P. stutzeri functional genes in oil reservoirs and excavate potential MEOR functional genes of P. stutzeri based on the view point of environmental evolution. This study is playing an important role in revealing the MEOR mechanisms in natural environmental of oil reservoirs.

前期工作中我们监测到施氏假单胞菌Pseudomonas stutzeri是一类微生物提高原油采收率（Microbial Enhanced Oil Recovery, MEOR)矿场试验过程中容易被激活的菌种；同时，基于16S rRNA基因序列我们初步揭示了油藏环境中P.stutzeri基因亚种（genomovar, gv.）多样性分布。本项目在前期工作基础上，针对油藏环境中P.stutzeri基因亚种多样性与油藏这一特殊环境之间的关系，通过rpoD基因克隆文库、纯菌分离、环境样品宏基因组测序以及纯菌基因组测序技术进一步研究MEOR矿场试验过程中以油藏环境为天然反应器的P.stutzeri基因亚种类型分布以及功能分布特点，从自然环境生物进化角度来诠释油藏环境中P.stutzeri功能基因形成机制，研究油藏P.stutzeri作为MEOR矿场试验采油功能菌的潜力。

P.stutzeri（施氏假单胞菌）是一类具有功能和基因亚种多样性的微生物，油藏中的P.stutzeri较为常见并具有采油功能。本项目系统地揭示了油藏环境中检测到的P.stutzeri能划分到4个已知的亚种类型，gv.1、gv.2、gv.3和gv.20以及2个未知的基因型，其中gv.1型的P.stutzeri在油藏环境中普遍存在。检测到未知的P.stutzeri基因类型表明，油藏中存在着大量的不同于其它环境的P.stutzeri亚种类型，这些基因类型的出现与某些油藏特殊环境有关。通过纯菌分离得到2株P. stutzeri通过系统发育分类不能被分到任何的已知P. stutzeri亚种类型，将这两株菌全基因组测序，并进行分子信息学分析，揭示油藏环境下P.stutzeri的烃降解、硝酸盐还原、低分子脂肪酸代谢的采油功能特点，在基因水平上获得油藏环境中P.stutzeri功能信息，证实P.stutzeri作为微生物提高原油采收率（MEOR）矿场试验采油功能菌的潜力。