好氧氨氧化过程中的关键酶及N_(2)O排放研究进展  

Key enzymes and N_(2)O emission in aerobic ammonia oxidation process

作　　者：杨裕然 李辉妙 李振轮 汪恩旭 YANG Yuran;LI Huimiao;LI Zhenlun;WANG Enxu(Chongqing Key Laboratory of Soil Multi-scale Interfacial Process,College of Resources and Environment,Southwest University,Chongqing 400716,China;Chongqing Key Laboratory of Plant Disease Biology,College of Plant Protection,Southwest University,Chongqing 400716,China)

机构地区：[1]西南大学资源环境学院土壤多尺度界面过程与调控重庆市重点实验室,重庆400716 [2]西南大学植物保护学院植物病害生物学重庆市高校重点实验室,重庆400716

出　　处：《微生物学报》2023年第9期3321-3334,共14页Acta Microbiologica Sinica

基　　金：国家自然科学基金(42077217)。

摘　　要：氧化亚氮(nitrous oxide,N_(2)O)排放量的持续增加对全球生态平衡造成了严重的威胁。微生物N_(2)O排放占主要来源。其中,好氧氨氧化过程是氨在有氧的条件下氧化为亚硝酸盐,其直接或间接地影响着全球产生N_(2)O与释放量。氨氧化古菌(ammonia-oxidizing archaea,AOA)、氨氧化细菌(ammonia-oxidizing bacteria,AOB)、全程氨氧化菌(complete ammonia oxidization,Comammox)和异养氨氧化菌(heterotrophic ammonium oxidizing bacteria,HAOB)是氨氧化过程中主要的参与者,明确这四类微生物N_(2)O产生的机制对缓解全球N_(2)O排放是必要的。本文综述了AOA、AOB、Comammox和HAOB在好氧氨氧化过程中驱动的N_(2)O产生途径,并结合酶学分析了一些关键酶在N_(2)O产生途径中的作用。本文旨在为调控生物N_(2)O排放提供理论基础。The increasing emission of nitrous oxide(N_(2)O)poses a serious threat to global ecological balance,to which microbes contribute a lot.Aerobic ammonia oxidation is the oxidation of ammonia to nitrite under aerobic conditions,which directly or indirectly affects the global production and release of N_(2)O.Ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),complete ammonia oxidizers(Comammox),and heterotrophic ammonia-oxidizing bacteria(HAOB)are major contributors to ammonia oxidation.It is important for the mitigation of N_(2)O emission to clarify how N_(2)O is produced by the four types of microorganisms.This paper reviewed the N_(2)O production pathways in AOA,AOB,Comammox and HAOB driven by the aerobic ammonia oxidation process.The roles of some key enzymes in the N_(2)O production pathways were elucidated through enzymatic analysis.Ammonia monooxygenase(AMO)is the first key enzyme in the autotrophic aerobic ammonia oxidation process,and the direct product of hydroxylamine oxidation is NO instead of NO_(2)^(–),which is then converted to NO_(2)^(–)by an unknown enzyme.The aerobic ammonia oxidation process and related enzymes of HAOB are not completely clear,and the issue of N_(2)O emission needs to be further studied.This paper aims to lay a theoretical basis for regulating biological N_(2)O emission.

关 键 词：好氧氨氧化 氨氧化微生物 酶学 氧化亚氮 一氧化氮 氮循环 

分 类 号：Q938[生物学—微生物学]