Pan Pan, Hong Bo, Mbadinga Serge Maurice, Wang Li-Ying, Liu Jin-Feng, Yang Shi-Zhong, Gu Ji-Dong, Mu Bo-Zhong
State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, 200237, China.
Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, 200237, China.
Appl Microbiol Biotechnol. 2017 Sep;101(18):7053-7063. doi: 10.1007/s00253-017-8422-2. Epub 2017 Jul 20.
Acetate is a key intermediate in anaerobic crude oil biodegradation and also a precursor for methanogenesis in petroleum reservoirs. The impact of iron oxides, viz. β-FeOOH (akaganéite) and magnetite (FeO), on the methanogenic acetate metabolism in production water of a high-temperature petroleum reservoir was investigated. Methane production was observed in all the treatments amended with acetate. In the microcosms amended with acetate solely about 30% of the acetate utilized was converted to methane, whereas methane production was stimulated in the presence of magnetite (FeO) resulting in a 48.34% conversion to methane. Methane production in acetate-amended, β-FeOOH (akaganéite)-supplemented microcosms was much faster and acetate consumption was greatly improved compared to the other conditions in which the stoichiometric expected amounts of methane were not produced. Microbial community analysis showed that Thermacetogenium spp. (known syntrophic acetate oxidizers) and hydrogenotrophic methanogens closely related to Methanothermobacter spp. were enriched in acetate and acetate/magnetite (FeO) microcosms suggesting that methanogenic acetate metabolism was through hydrogenotrophic methanogenesis fueled by syntrophic acetate oxidizers. The acetate/β-FeOOH (akaganéite) microcosms, however, differed by the dominance of archaea closely related to the acetoclastic Methanosaeta thermophila. These observations suggest that supplementation of β-FeOOH (akaganéite) accelerated the production of methane further, driven the alteration of the methanogenic community, and changed the pathway of acetate methanogenesis from hydrogenotrophic methanogenesis fueled by syntrophic acetate oxidizers to acetoclastic.
乙酸盐是原油厌氧生物降解的关键中间体，也是油藏中甲烷生成的前体。研究了氧化铁，即β-氢氧化铁（针铁矿）和磁铁矿（FeO）对高温油藏采出水中乙酸盐产甲烷代谢的影响。在用乙酸盐修正的所有处理中均观察到甲烷生成。在仅用乙酸盐修正的微观世界中，约30%被利用的乙酸盐转化为甲烷，而在存在磁铁矿（FeO）的情况下甲烷生成受到刺激，导致48.34%的乙酸盐转化为甲烷。与未产生化学计量预期量甲烷的其他条件相比，在用乙酸盐修正、添加β-氢氧化铁（针铁矿）的微观世界中，甲烷生成要快得多，乙酸盐消耗也大大改善。微生物群落分析表明，嗜热乙酸菌属（已知的互营乙酸盐氧化菌）和与嗜热甲烷杆菌属密切相关的氢营养型产甲烷菌在乙酸盐和乙酸盐/磁铁矿（FeO）微观世界中富集，这表明乙酸盐产甲烷代谢是通过互营乙酸盐氧化菌提供燃料的氢营养型甲烷生成途径进行的。然而，乙酸盐/β-氢氧化铁（针铁矿）微观世界的不同之处在于，与嗜热乙酸甲烷八叠球菌密切相关的古菌占主导地位。这些观察结果表明，添加β-氢氧化铁（针铁矿）进一步加速了甲烷的生成，推动了产甲烷群落的变化，并将乙酸盐甲烷生成途径从互营乙酸盐氧化菌提供燃料的氢营养型甲烷生成转变为乙酸裂解型。
