海洋氨氧化古菌与氨氧化细菌在N_2O生成机制中贡献研究

Contribution of ammonia oxidizing archaea and ammonia oxidizing bacteria in the mechanism of N_2O formation in ocean

氧化亚氮(N_2O)是一种重要的痕量温室气体,而且在光照条件下平流层的N_2O会与O_3发生光化学反应,破坏臭氧层。海洋是大气中N_2O的主要来源之一,海洋中N_2O主要通过硝化和反硝化作用产生,而氨氧化作用是硝化作用的关键(限速)步骤,氨氧化古菌可能是氨氧化过程的主要执行者。本文先概述海洋中N_2O分布以及影响氨氧化古菌(Ammonia oxidizing archaea,AOA)和氨氧化细菌(Ammonia oxidizing bacteria,AOB)的amo A(ammonia monooxygenase)丰度与活性的因素以及N_2O生成机制研究现状,进而总结AOA和AOB在海洋N_2O生成机制中起到的关键作用,最后结合全球气候变化、海洋酸化以及大洋OMZ区域扩大等前沿科学问题,对AOA、AOB以及N_2O的生成机制研究进行了展望。

Nitrous oxide is an important trace greenhouse gas which also acts as an ozone depletory. Ocean is one of the main sources of N2O in the atmosphere. The emission of nitrous oxide （ N2O） in the Marine environment is often considered to be the result of microbial activities such as nitrification and denitrification. Ammonia oxidation is the key step of nitrification, and ammonia oxidizing archaea is considered to be the main practitioner of ammonia oxidation process in ocean. In this paper, the distribution of N2O, the elements affecting abundance of amoA from ammonia ox- idizing archaea（AOA） and ammonia oxidizing bacteria （AOB） , and the progress of N2O foring mechanism by AOA and AOB are reviewed. Finally possible AOA and AOB and N2O formation mechanism under back ground of global climate change, ocean acidification and extending of ocean OMZ are discussed.