Dong Hao, Zhang Fan, Xu Ting, Liu Yulong, Du Ying, Wang Chen, Liu Tiansheng, Gao Ji, He Yanlong, Wang Xiaotong, Sun Shanshan, She Yuehui
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023, China.
The Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism, Ministry of Education, College of Energy Resources, China University of Geosciences (Beijing), Beijing 100083, China.
Sci Total Environ. 2022 Sep 20;840:156577. doi: 10.1016/j.scitotenv.2022.156577. Epub 2022 Jun 7.
Fe(III) may be reasonably considered as one of the most important electron acceptors in petroleum reservoir ecosystems. The microbial mineralization of clay minerals, especially montmorillonite, is also of great significance to the exploration of petroleum and gas reservoirs. The bioreduction mechanisms of iron-poor minerals in petroleum reservoirs have been poorly investigated. This study investigated the bioreduction of montmorillonite by dissimilatory iron-reducing bacteria (DIRB) in petroleum reservoirs based on culture-independent and culture-dependent methods. Microbial diversity analysis revealed that Halolactibacillus, Bacillus, Alkaliphilus, Shewanella, Clostridium, and Pseudomonas were the key genera involved in the bioreduction of Fe(III). Through the traditional culture-dependent method, most of the key genera were isolated from the samples collected from petroleum reservoirs. Traditional culture-dependent methods can be used to reveal the metabolic characteristics of microorganisms (such as iron-reduction efficiency) to further elucidate the roles of different species (B. subtilis and B. alkalitelluris) in the environment. Moreover, many species with high iron-reduction efficiencies and relatively low abundances in the samples, such as Tessaracoccus and Flaviflexus, were isolated from petroleum reservoirs for the first time. The combination of culture-dependent and culture-independent methods can be used to further the understanding of the microbial communities and the metabolic characteristics of DIRB in petroleum reservoirs. Structural alterations that occurred during the interactions of microorganisms and montmorillonite were revealed through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD). The physical and chemical analysis results demonstrated that microorganisms from petroleum reservoirs can dissolve iron-poor montmorillonite and promote the release of interlayer water. The secondary minerals illite and clinoptilolite were observed in bioreduced smectite. The formation of secondary minerals was closely related to the dissolution degrees of minerals based on iron reduction.
铁（III）可被合理地视为石油储层生态系统中最重要的电子受体之一。粘土矿物，尤其是蒙脱石的微生物矿化作用，对油气藏勘探也具有重要意义。石油储层中贫铁矿物的生物还原机制研究较少。本研究基于非培养和培养依赖方法，研究了石油储层中异化铁还原细菌（DIRB）对蒙脱石的生物还原作用。微生物多样性分析表明，嗜盐乳杆菌、芽孢杆菌、嗜碱菌、希瓦氏菌、梭菌和假单胞菌是参与铁（III）生物还原的关键属。通过传统的培养依赖方法，从石油储层采集的样品中分离出了大多数关键属。传统的培养依赖方法可用于揭示微生物的代谢特征（如铁还原效率），以进一步阐明不同物种（枯草芽孢杆菌和碱土芽孢杆菌）在环境中的作用。此外，首次从石油储层中分离出了许多样品中铁还原效率高但丰度相对较低的物种，如八叠球菌和黄弯菌。培养依赖和非培养方法的结合可用于进一步了解石油储层中微生物群落和DIRB的代谢特征。通过扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和X射线粉末衍射（XRD）揭示了微生物与蒙脱石相互作用过程中发生的结构变化。物理和化学分析结果表明，石油储层中的微生物可以溶解贫铁蒙脱石并促进层间水的释放。在生物还原的蒙脱石中观察到了次生矿物伊利石和斜发沸石。次生矿物的形成与基于铁还原的矿物溶解程度密切相关。
