Genomics and Ecology of Novel N2O-Reducing Microorganisms. Issue 1 (January 2018)

• Record Type: Journal Article
• Authors: Hallin, Sara; Philippot, Laurent; Löffler, Frank E.; Sanford, Robert A.; Jones, Christopher M.
• Is Part Of: Trends in microbiology. Volume 26:Issue 1(2018)
• Page Start: 43
• Page End: 55
• Publication Date: 2018-01
• Subjects: climate change -- denitrification -- greenhouse gas -- nitrogen cycle -- nitrogen loss -- nitrous oxide; Microbiology -- Periodicals; Infection -- Periodicals; Virulence (Microbiology) -- Periodicals; Infection -- Periodicals; Microbiology -- Periodicals; Virulence -- Periodicals; Microbiologie -- Périodiques; Infection -- Périodiques; Virulence (Microbiologie) -- Périodiques; Infection; Microbiology; Virulence (Microbiology); 579
• DOI: 10.1016/j.tim.2017.07.003
• Languages: English
• ISSNs: 0966-842X

Abstract

Abstract : Microorganisms with the capacity to reduce the greenhouse gas nitrous oxide (N2 O) to harmless dinitrogen gas are receiving increased attention due to increasing N2 O emissions (and our need to mitigate climate change) and to recent discoveries of novel N2 O-reducing bacteria and archaea. The diversity of denitrifying and nondenitrifying microorganisms with capacity for N2 O reduction was recently shown to be greater than previously expected. A formerly overlooked group (clade II) in the environment include a large fraction of nondenitrifying N2 O reducers, which could be N2 O sinks without major contribution to N2 O formation. We review the recent advances about fundamental understanding of the genomics, physiology, and ecology of N2 O reducers and the importance of these findings for curbing N2 O emissions. Trends: N2 O is produced in several microbial processes, but N2 O reduction is limited to a single process catalyzed by the N2 O reductase present among taxonomically diverse bacteria and archaea. This enzyme is used for energy conservation through anaerobic respiration, detoxification, or removal of excess electrons. The N2 O reductase has evolved into two lineages, clade I and the recently described clade II. Surveys indicate that clade II N2 O reductase (NosZ) is abundant in many biomes. Genome analyses and culture-based studies suggest that the physiology of N2 O reduction differs between the clades. Evidence from community ecology supports niche differentiation of organisms with either type of N2 O reductase, and within the two clades. Identifying factors that drive physiological and ecological responses of N2 O-reducing communities could lead to effective and innovative strategies to curb N2 O emissions.