厌氧氨氧化菌的中心代谢研究进展

Central metabolism of anammox bacteria——A review

厌氧氨氧化是以NH+4为电子供体,以NO-2为电子受体产生N2的生物反应。厌氧氨氧化菌是厌氧氨氧化过程的执行者,在废水生物脱氮和地球氮素循环中扮演着重要角色。研究厌氧氨氧化菌的代谢特性,将有助于理解厌氧氨氧化过程,开发厌氧氨氧化工艺。厌氧氨氧化菌是化能自养型细菌,以CO2或HCO-3为碳源,并通过偶联NH 4+氧化和NO-2还原的生物反应获得能量。在NH+4/NO-2的生物氧化还原反应过程中,检出了中间产物N2H4,但未检出其他中间产物(如NH2OH、NO)。此外,由基因组信息推断,厌氧氨氧化菌通过乙酰-CoA途径固定碳素。上述基于基因组信息推断的厌氧氨氧化途径与现有的实验资料、热力学计算和生化分析相吻合,并遵守奥卡姆剃刀原理。

Anaerobic ammonium oxidation（anammox） is a biological process by which ammonium is oxidized to dinitrogen gas by using nitrite as the electrons acceptor.Anaerobic ammonium-oxidizing bacteria play an important role in nitrogen removal from wastewater and global N-cycle.The study of metabolism of anammox bacteria will help us understand the anammox mechanism and develop anammox biotechnology.Anammox bacteria are chemoautotrophic bacteria that use CO2 or HCO-3 as carbon source and obtain their energy from the conversion of ammonium and nitrite into dinitrogen gas.Hydrazine has been detected as an intermediate in the anammox pathway,while hydroxylamine and nitric oxide have not been detected yet.The genomic data indicate that anammox bacteria fix carbon dioxide through acetyl-CoA pathway.The proposed anammox pathway is consistent with the available experimental data,thermodynamical calculation and biochemical determination and as well as the Ockhams razor principal.