Landfill intermediate cover soil microbiomes and their potential for mitigating greenhouse gas emissions revealed through metagenomics.

Autor: Lienhart PH; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States., Rohra V; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States., Clement C; Department of Microbiology, Oregon State University, Corvallis, OR, United States., Toppen LC; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States. Electronic address: Lucinda.Toppen@uvm.edu., DeCola AC; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States., Rizzo DM; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States; Gund Institute for Environment, University of Vermont, Burlington, VT, United States. Electronic address: drizzo@uvm.edu., Scarborough MJ; Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT, United States; Gund Institute for Environment, University of Vermont, Burlington, VT, United States. Electronic address: mscarbor@uvm.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 May 15; Vol. 925, pp. 171697. Date of Electronic Publication: 2024 Mar 15.
DOI: 10.1016/j.scitotenv.2024.171697
Abstrakt: Landfills are a major source of anthropogenic methane emissions and have been found to produce nitrous oxide, an even more potent greenhouse gas than methane. Intermediate cover soil (ICS) plays a key role in reducing methane emissions but may also result in nitrous oxide production. To assess the potential for microbial methane oxidation and nitrous oxide production, long sequencing reads were generated from ICS microbiome DNA and reads were functionally annotated for 24 samples across ICS at a large landfill in New York. Further, incubation experiments were performed to assess methane consumption and nitrous oxide production with varying amounts of ammonia supplemented. Methane was readily consumed by microbes in the composite ICS and all incubations with methane produced small amounts of nitrous oxide even when ammonia was not supplemented. Incubations without methane produced significantly less nitrous oxide than those incubated with methane. In incubations with methane added, the observed specific rate of methane consumption was 0.776 +/- 0.055 μg CH 4 g dry weight (DW) soil -1  h -1 and the specific rate of nitrous oxide production was 3.64 × 10 -5 +/- 1.30 × 10 -5  μg N 2 O g DW soil -1  h -1 . The methanotrophs Methylobacter and an unclassified genus within the family Methlyococcaceae were present in the original ICS samples and the incubation samples, and their abundance increased during incubations with methane. Genes encoding particulate methane monooxygenase/ ammonia monooxygenase (pMMO) were much more abundant than genes encoding soluble methane monooxygenase (sMMO) across the landfill ICS. Genes encoding proteins that convert hydroxylamine to nitrous oxide were not highly abundant in the ICS or incubation metagenomes. In total, these results suggest that although ammonia oxidation via methanotrophs may result in low levels of nitrous oxide production, ICS microbial communities have the potential to greatly reduce the overall global warming potential of landfill emissions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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