Sustained bacterial N2O reduction at acidic pH

Guang He; Gao Chen; Yongchao Xie; Cynthia M Swift; Diana Ramirez; Gyuhyon Cha; Konstantinos T Konstantinidis; Mark Radosevich; Frank E Löffler

doi:10.1038/s41467-024-48236-x

Sustained bacterial N₂O reduction at acidic pH

Nat Commun. 2024 May 15;15(1):4092. doi: 10.1038/s41467-024-48236-x.

Authors

Guang He^{1

2}, Gao Chen^{2

3}, Yongchao Xie^{2

4}, Cynthia M Swift^{2

3}, Diana Ramirez^{5

6}, Gyuhyon Cha⁷, Konstantinos T Konstantinidis⁷, Mark Radosevich¹, Frank E Löffler^{8

9

10

11

12}

Affiliations

¹ Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
² Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
³ Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA.
⁴ Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
⁵ Department of Microbiology, The University of Tennessee Knoxville, Knoxville, TN, 37996, USA.
⁶ Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
⁷ School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
⁸ Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA. frank.loeffler@utk.edu.
⁹ Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA. frank.loeffler@utk.edu.
¹⁰ Center for Environmental Biotechnology, The University of Tennessee, Knoxville, Knoxville, TN, 37996, USA. frank.loeffler@utk.edu.
¹¹ Department of Microbiology, The University of Tennessee Knoxville, Knoxville, TN, 37996, USA. frank.loeffler@utk.edu.
¹² Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. frank.loeffler@utk.edu.

Abstract

Nitrous oxide (N₂O) is a climate-active gas with emissions predicted to increase due to agricultural intensification. Microbial reduction of N₂O to dinitrogen (N₂) is the major consumption process but microbial N₂O reduction under acidic conditions is considered negligible, albeit strongly acidic soils harbor nosZ genes encoding N₂O reductase. Here, we study a co-culture derived from acidic tropical forest soil that reduces N₂O at pH 4.5. The co-culture exhibits bimodal growth with a Serratia sp. fermenting pyruvate followed by hydrogenotrophic N₂O reduction by a Desulfosporosinus sp. Integrated omics and physiological characterization revealed interspecies nutritional interactions, with the pyruvate fermenting Serratia sp. supplying amino acids as essential growth factors to the N₂O-reducing Desulfosporosinus sp. Thus, we demonstrate growth-linked N₂O reduction between pH 4.5 and 6, highlighting microbial N₂O reduction potential in acidic soils.

MeSH terms

Coculture Techniques
Fermentation
Hydrogen-Ion Concentration
Nitrogen / metabolism
Nitrous Oxide* / metabolism
Oxidation-Reduction
Oxidoreductases / genetics
Oxidoreductases / metabolism
Pyruvic Acid / metabolism
Serratia* / genetics
Serratia* / metabolism
Soil / chemistry
Soil Microbiology*

Grants and funding

1831599/National Science Foundation (NSF)