Transcription of Nitrogen Fixation Genes Is Enhanced at Unfavorably High Oxygen Concentrations for Diazotrophic Growth in a Methane-oxidizing Bacterium.

ABSTRACT: Since nitrogenase is intrinsically sensitive to oxygen (O₂), diverse aerobic diazotrophs need strategies to cope with nitrogenase damage by O₂. In the present study, we investigated the mechanisms by which aerobic methane-oxidizing bacteria (methanotrophs) enable the concurrent activities of methane monooxygenase, which uses O₂, and nitrogenase in the cytoplasm of the same cell. By using ¹⁵N labeling, we confirmed the capacity of alphaproteobacterial methanotroph Methylosinus sp. 3S-1 for nitrogen fixation and diazotrophic growth across a wide range of O₂ concentrations <20%. When the initial O₂ concentration was increased from 2 to 20% in a diazotrophic culture, similar decreases were observed in fixed nitrogen and NifH pro

SUBMITTER: Abdela AA 

PROVIDER: S-EPMC12727197 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature