海洋奇古菌门认知的拓展:从新类群到新功能

The expanding knowledge of marine Thaumarchaeota:from new groups to new functions

奇古菌门是全球海洋中的重要微生物类群,在海洋原核浮游生物中的比例可达20%-40%。作为一类化能无机自养微生物,奇古菌门成员可通过氧化氨获得能量,实现不依赖光照的无机碳固定,在碳、氮等元素的地球化学循环中起关键作用。奇古菌门是海洋中氨氧化反应的主要执行者,其化能合成的有机质是海洋特别是深海环境中微生物的重要能量来源。随着研究的逐步深入,有关该类群生理代谢特性的认知不断被拓展,包括奇古菌门异养代谢的揭示、不具氨氧化能力类群在深海中的发现,以及最新报道的奇古菌门在厌氧条件下介导氧气、氧化亚氮和氮气的产生等。这些研究揭示了奇古菌门参与海洋生物地球化学循环和气候变化调节的新机制,为围绕该类群的深入探究和培养提供了新的思路和方向。本文从群落组成、环境适应、生态功能、进化历史和培养现状等方面综述了近年来有关海洋奇古菌门的新发现和新认识,以期增进对该类群的了解。

Thaumarchaeota is an important microbial group in the global ocean,accounting for 20%-40%of the total marine prokaryotic plankton.As a group of chemautotrophs,Thaumarchaeota members are able to oxidize ammonia and leverage the released energy to fix inorganic carbon in the dark.They thus play a crucial role in the biogeochemical cycling of carbon and nitrogen.Thaumarchaeota are the major driver of ammonia oxidization in the ocean.The primary production by Thaumarchaeota through chemosynthesis serves as an important energy source for marine microorganisms,especially those in the deep-sea environments.With increasing efforts,the knowledge on the physiological and metabolic features of this group is expanded.This includes the evidence of heterotrophic metabolism,the discovery of thaumarchaeotal groups with no ammonia oxidation capacity in the deep sea,and the production of oxygen,nitrous oxide,and dinitrogen under anaerobic conditions.These studies reveal the new mechanisms of Thaumarchaeota in participating in the marine biogeochemical cycling and regulating climate change,which provide novel insights and perspectives for further studies and culture.In this study,we review new discoveries about marine Thaumarchaeota in recent years in terms of community composition,environmental adaptation,ecological function,evolutionary history,and culture status,with an aim of improving the understanding of this group.