A pathway for biological methane production using bacterial iron-only nitrogenase.

Autor: Zheng Y; Department of Microbiology, University of Washington, Seattle, WA, USA., Harris DF; Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA., Yu Z; Department of Chemical Engineering, University of Washington, Seattle, WA, USA., Fu Y; Department of Chemical Engineering, University of Washington, Seattle, WA, USA., Poudel S; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA., Ledbetter RN; Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA., Fixen KR; Department of Microbiology, University of Washington, Seattle, WA, USA., Yang ZY; Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA., Boyd ES; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA., Lidstrom ME; Department of Microbiology, University of Washington, Seattle, WA, USA.; Department of Chemical Engineering, University of Washington, Seattle, WA, USA., Seefeldt LC; Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA., Harwood CS; Department of Microbiology, University of Washington, Seattle, WA, USA. csh5@uw.edu.
Jazyk: angličtina
Zdroj: Nature microbiology [Nat Microbiol] 2018 Mar; Vol. 3 (3), pp. 281-286. Date of Electronic Publication: 2018 Jan 15.
DOI: 10.1038/s41564-017-0091-5
Abstrakt: Methane (CH 4 ) is a potent greenhouse gas that is released from fossil fuels and is also produced by microbial activity, with at least one billion tonnes of CH 4 being formed and consumed by microorganisms in a single year 1 . Complex methanogenesis pathways used by archaea are the main route for bioconversion of carbon dioxide (CO 2 ) to CH 4 in nature 2-4 . Here, we report that wild-type iron-iron (Fe-only) nitrogenase from the bacterium Rhodopseudomonas palustris reduces CO 2 simultaneously with nitrogen gas (N 2 ) and protons to yield CH 4 , ammonia (NH 3 ) and hydrogen gas (H 2 ) in a single enzymatic step. The amount of CH 4 produced by purified Fe-only nitrogenase was low compared to its other products, but CH 4 production by this enzyme in R. palustris was sufficient to support the growth of an obligate CH 4 -utilizing Methylomonas strain when the two microorganisms were grown in co-culture, with oxygen (O 2 ) added at intervals. Other nitrogen-fixing bacteria that we tested also formed CH 4 when expressing Fe-only nitrogenase, suggesting that this is a general property of this enzyme. The genomes of 9% of diverse nitrogen-fixing microorganisms from a range of environments encode Fe-only nitrogenase. Our data suggest that active Fe-only nitrogenase, present in diverse microorganisms, contributes CH 4 that could shape microbial community interactions.
Databáze: MEDLINE