Abstract Methanogenesis for generation of renewable energy in geological ecosystems may be influenced by the in-situ iron oxides available. This study investigated the natural iron minerals (Magnetite, Hematite and Specularite) on rate of energy generation and biochemical pathways in the presence of methanol as a model substrate using microbial consortium enriched from oilfield production water. Enhanced (15%) and stimulated energy generation was achieved in the treatments amended with iron minerals compared to the controls without any amendment. The mineral amended treatments resulted in enrichment of bacterial community for Firmicutes, but no changes were observed in the archaea (Methanosarcina mazei). The dynamic changes of acetate and methane concentrations in different treatments during incubation indicated anaerobic fermentation of methanol to acetate occurred prior to syntrophic acetate oxidation coupling with hydrogenotrophic methanogenesis for methane bioenergy production, which was further verified thermodynamically. Iron minerals were suggested to serve as electron donors and conductive networks between syntrophic partners in the microbial community facilitating direct interspecies electron transfer for efficient energy generation. The investigation yielded prospects on efficient generation of renewable energy and environmental sustainability by natural iron minerals. It also provides insights about the key processes in the petroleum reservoirs, deep biosphere and engineered anaerobic systems.

中文翻译：

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用天然铁矿物质修正的富集微生物群中增强的能量产生和改变的生化途径

摘要 地质生态系统中用于产生可再生能源的产甲烷作用可能受到可利用的原位氧化铁的影响。本研究使用从油田生产水中富集的微生物群落，研究了在甲醇作为模型底物存在的情况下，天然铁矿物（磁铁矿、赤铁矿和镜铁矿）对能量产生速率和生化途径的影响。与没有任何修改的对照相比，在用铁矿物质修改的处理中实现了增强 (15%) 和刺激的能量产生。矿物质修正处理导致厚壁菌的细菌群落富集，但在古细菌（Methanosarcina mazei）中没有观察到变化。孵化过程中不同处理中乙酸盐和甲烷浓度的动态变化表明，在用于甲烷生物能源生产的同养乙酸盐氧化与氢营养产甲烷作用耦合之前，甲醇厌氧发酵为乙酸盐，这在热力学上得到了进一步验证。铁矿物被建议作为电子供体和微生物群落中同养伙伴之间的传导网络，促进直接的种间电子转移，从而有效地产生能量。该调查为利用天然铁矿物高效生产可再生能源和环境可持续性带来了前景。它还提供了有关石油储层、深层生物圈和工程厌氧系统中关键过程的见解。