Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba 305-8567, Japan.
Nat Commun. 2013;4:1998. doi: 10.1038/ncomms2998.
Deep subsurface formations (for example, high-temperature oil reservoirs) are candidate sites for carbon capture and storage technology. However, very little is known about how the subsurface microbial community would respond to an increase in CO2 pressure resulting from carbon capture and storage. Here we construct microcosms mimicking reservoir conditions (55 °C, 5 MPa) using high-temperature oil reservoir samples. Methanogenesis occurs under both high and low CO2 conditions in the microcosms. However, the increase in CO2 pressure accelerates the rate of methanogenesis to more than twice than that under low CO2 conditions. Isotope tracer and molecular analyses show that high CO2 conditions invoke acetoclastic methanogenesis in place of syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis that typically occurs in this environment (low CO2 conditions). Our results present a possibility of carbon capture and storage for enhanced microbial energy production in deep subsurface environments that can mitigate global warming and energy depletion.
深部地下地层（例如，高温油藏）是碳捕获和封存技术的候选场地。然而，对于地下微生物群落将如何应对碳捕获和封存导致的 CO2 压力增加，人们知之甚少。在这里，我们使用高温油藏样品构建了模拟油藏条件（55°C，5 MPa）的微环境。在微环境中，高和低 CO2 条件下均会发生甲烷生成。然而，CO2 压力的增加将甲烷生成的速率加速到高于低 CO2 条件下的两倍以上。同位素示踪和分子分析表明，高 CO2 条件会引发乙酸营养型甲烷生成，而不是通常在这种环境（低 CO2 条件）中发生的共营养乙酸氧化耦合氢营养型甲烷生成。我们的研究结果提出了一种在深部地下环境中进行碳捕获和封存以增强微生物能源生产的可能性，这可以缓解全球变暖和能源枯竭。
