The atmosphere has recently been recognized as a major source of energy sustaining life. Diverse aerobic bacteria oxidize the three most abundant reduced trace gases in the atmosphere, namely hydrogen (H₂), carbon monoxide (CO) and methane (CH₄). This Review describes the taxonomic distribution, physiological role and biochemical basis of microbial oxidation of these atmospheric trace gases, as well as the ecological, environmental, medical and astrobiological importance of this process. Most soil bacteria and some archaea can survive by using atmospheric H₂ and CO as alternative energy sources, as illustrated through genetic studies on Mycobacterium cells and Streptomyces spores. Certain specialist bacteria can also grow on air alone, as confirmed by the landmark characterization of Methylocapsa gorgona, which grows by simultaneously consuming atmospheric CH₄, H₂ and CO. Bacteria use high-affinity lineages of metalloenzymes, namely hydrogenases, CO dehydrogenases and methane monooxygenases, to utilize atmospheric trace gases for aerobic respiration and carbon fixation. More broadly, trace gas oxidizers enhance the biodiversity and resilience of soil and marine ecosystems, drive primary productivity in extreme environments such as Antarctic desert soils and perform critical regulatory services by mitigating anthropogenic emissions of greenhouse gases and toxic pollutants.

大气最近被认为是维持生命的主要能量来源。多种好氧细菌氧化大气中三种最丰富的还原痕量气体，即氢气 (H ₂ )、一氧化碳 (CO) 和甲烷 (CH ₄ )。本综述描述了这些大气痕量气体微生物氧化的分类学分布、生理作用和生化基础，以及该过程的生态、环境、医学和天体生物学重要性。大多数土壤细菌和一些古细菌可以通过使用大气中的 H ₂和 CO 作为替代能源来生存，正如对分枝杆菌细胞和链霉菌的遗传研究所表明的那样孢子。某些特殊细菌也可以单独在空气中生长，正如Methylocapsa gorgona具有里程碑意义的特征所证实的那样，它通过同时消耗大气中的 CH ₄、H ₂和 CO 来生长。细菌使用金属酶的高亲和力谱系，即氢化酶、CO 脱氢酶和甲烷单加氧酶，利用大气中的痕量气体进行有氧呼吸和碳固定。更广泛地说，痕量气体氧化剂增强了土壤和海洋生态系统的生物多样性和复原力，推动了南极沙漠土壤等极端环境中的初级生产力，并通过减少温室气体和有毒污染物的人为排放发挥了关键的监管作用。