Contribution of Microorganisms with the Clade II Nitrous Oxide Reductase to Suppression of Surface Emissions of Nitrous Oxide

• DOI: 10.1021/acs.est.3c07972
• Publication Date: 2024-04-12T18:15:33Z
• Authors: Kristopher A. Hunt; Alex V. Carr; Anne E. Otwell; Jacob J. Valenzuela; Kathleen S. Walker; Emma R. Dixon; Lauren M. Lui; Torben N. Nielsen; Samuel Bowman; Frederick von Netzer; Ji-Won Moon; Christopher W. Sc...; Miguel Rodriguez Jr; Kenneth Lowe; Dominique Joyner; Katherine J. Davis; Xiaoqin Wu; Romy Chakraborty; Matthew W. Fields; Jizhong Zhou; Terry C. Hazen; Adam P. Arkin; Scott D. Wankel; Nitin S. Baliga; David A. Stahl
• Keywords: Nitrous oxide; Aerobic denitrification; Nitrous-oxide reductase

The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis oxide flux from observation wells proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape surface. To better understand controls emission at this site, we used combination isotopic, geochemical, molecular analyses show that chemodenitrification bacterial denitrification major in subsurface, where low DO, pH, correlated with significant production. Depth-resolved metagenomes showed consumption near was an enrichment Clade II reducers, consistent growing appreciation their importance controlling release atmosphere. Our work also provides evidence reduction pH 4, well below accepted limit 5.