氨氧化古菌及其对氮循环贡献的研究进展

Ammonia-oxidizing archaea and their contribution to global nitrogen cycling: a review

摘要:

硝化作用先将氨氮氧化为亚硝酸盐氮并进一步氧化为硝酸盐氮，这一过程是氮进行全球生物化学循环的重要环节。随着氨氧化古菌(Ammonia-oxidizing archaea，AOA)基因组序列中氨单加氧酶编码基因(amoA)的发现以及AOA在实验室条件下的成功培养(包括分离纯化和富集培养)，基于分子生物学的研究表明AOA在各种环境广泛存在，且多数生境中它的数量远远超过氨氧化细菌(Ammonia-oxidizing bacteria，AOB)。AOA相对于AOB在氮循环中的贡献也引起了多方面的论证和争论。本文就氨氧化古菌的生态分布、系统进化、生境存在丰度及参与硝化作用等进行综述，指出不同生境AOA的活性及其对氮循环的重要性仍需做进一步的研究。

Abstract:

Nitrification (oxidation of ammonia to nitrate via nitrite) plays a crucial role in the global nitrogen cycling. Along with the discovery of ammonia monooxygenase coding gene (amoA) sequences in archaea and the successful cultivation (isolation and enrichment) of ammonia-oxidizing archaea (AOA), it has been found that AOA was more abundant than AOB in most environments. And the contribution of AOA vs AOB to the nitrogen cycling is still under debate. In this mini-review, the ecological distribution, evolution, abundance and potential function involved the microbial nitrification were summarized based on the current knowledge. Furthermore, the perspective insights were discussed for the future research.