Most of the oil in low temperature, non‐uplifted reservoirs is biodegraded due to millions of years of microbial activity, including via methanogenesis from crude oil. To evaluate stimulating additional methanogenesis in already heavily biodegraded oil reservoirs, oil sands samples were amended with nutrients and electron acceptors, but oil sands bitumen was the only organic substrate. Methane production was monitored for over 3000 days. Methanogenesis was observed in duplicate microcosms that were unamended, amended with sulfate or that were initially oxic, however methanogenesis was not observed in nitrate‐amended controls. The highest rate of methane production was 0.15 μmol CH₄ g⁻¹ oil d⁻¹, orders of magnitude lower than other reports of methanogenesis from lighter crude oils. Methanogenic Archaea and several potential syntrophic bacterial partners were detected following the incubations. GC–MS and FTICR–MS revealed no significant bitumen alteration for any specific compound or compound class, suggesting that the very slow methanogenesis observed was coupled to bitumen biodegradation in an unspecific manner. After 3000 days, methanogenic communities were amended with benzoate resulting in methanogenesis rates that were 110‐fold greater. This suggests that oil‐to‐methane conversion is limited by the recalcitrant nature of oil sands bitumen, not the microbial communities resident in heavy oil reservoirs.

中文翻译：

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在严重生物降解的石油储层中，厌氧微生物群落及其在生物能源生产中的潜力。

由于数百万年的微生物活动（包括通过原油甲烷化作用），大多数处于低温，未隆升储层的石油已被生物降解。为了评估在已经严重生物降解的油藏中刺激其他甲烷生成的作用，对油砂样品进行了养分和电子受体的修正，但油砂沥青是唯一的有机底物。监测甲烷生产超过3000天。在未修改，用硫酸盐修改过或最初为有氧的重复微观世界中观察到甲烷生成，但是在硝酸盐修改过的对照中未观察到甲烷生成。甲烷的最高生产率为0.15μmolCH ₄ g ^-1油d ^-1，比其他较轻质原油产甲烷的报道要低几个数量级。孵育后检测到产甲烷的古细菌和几种潜在的同养细菌伴侣。GC-MS和FTICR-MS并未显示任何特定化合物或化合物类别的沥青显着变化，这表明观察到的非常缓慢的产甲烷作用以非特异性方式与沥青生物降解相关。3000天后，用苯甲酸酯修饰产甲烷菌群落，使产甲烷率提高110倍。这表明，油砂向甲烷的转化受油砂沥青的顽固性限制，而不是重油油藏中的微生物群落。