Copper’s dual role in aerobic methane oxidation coupled with aerobic denitrification: Boosts CH4-derived carbon for denitrification but inhibits it via methanobactin competition
Yujing Fan , Qing Yang , Xueyou Liang , Man Feng , Zhiling Gao , Miaomiao Chen , Wenlin Wang , Chunjing Liu
{"title":"Copper’s dual role in aerobic methane oxidation coupled with aerobic denitrification: Boosts CH4-derived carbon for denitrification but inhibits it via methanobactin competition","authors":"Yujing Fan , Qing Yang , Xueyou Liang , Man Feng , Zhiling Gao , Miaomiao Chen , Wenlin Wang , Chunjing Liu","doi":"10.1016/j.wroa.2025.100355","DOIUrl":null,"url":null,"abstract":"<div><div>Aerobic methane oxidation coupled with aerobic denitrification (AME-AD) has the capability to remove nitrate and reduce methane (CH<sub>4</sub>) under aerobic conditions. However, the impact of copper as a cofactor in wastewater and its underlying mechanism in the AME-AD process remains unexplored. This study conducted a series of batch experiments, examining the influence of copper concentrations (ranging from 0 to 20 μM Cu<sup>2+</sup>) on denitrification, CH<sub>4</sub> oxidation, nitrous oxide (N<sub>2</sub>O) generation, and the expressions of key functional genes within a synthetic AME-AD community. The results revealed that Cu<sup>2+</sup> concentrations significantly affected the denitrification capacity of the AME-AD system. Specifically, the 10 μM Cu<sup>2+</sup>treatment exhibited optimal AME-AD performance, achieving a denitrification rate of 0.031 mg·h<sup>-1</sup> and a CH<sub>4</sub> oxidation efficiency of 98 %. However, this treatment had a high proportion of N<sub>2</sub>O generation (4.79 %), ultimately resulting in a decrease in the overall reduction of total greenhouse gases to 802.5 mg CO<sub>2</sub>-e. Moreover, the Cu<sup>2+</sup> concentrations had a significant impact on the expression of crucial genes associated with aerobic denitrification (<em>napA, nosZ</em>) and CH<sub>4</sub> oxidation (<em>pmoA</em>). Specifically, the highest abundance of functional genes related to denitrification was observed in 15 μM Cu<sup>2+</sup> treatment, with <em>napA</em> reaching 3.75 × 10<sup>10</sup> copies·g<sup>-1</sup> and <em>nosZ</em> attaining 1.32 × 10<sup>9</sup> copies·g<sup>-1</sup> at 192 h. Conversely, the peak <em>pmoA</em> copy number of 4.8 × 10<sup>9</sup> copies·g<sup>-1</sup> was noted in 10 μM Cu<sup>2+</sup> treatment. These discoveries enhance our comprehension of how copper modulates the AME-AD process and facilitate its application in treating low-C/N wastewater and mitigating greenhouse gas emissions.</div></div>","PeriodicalId":52198,"journal":{"name":"Water Research X","volume":"28 ","pages":"Article 100355"},"PeriodicalIF":7.2000,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research X","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2589914725000544","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Aerobic methane oxidation coupled with aerobic denitrification (AME-AD) has the capability to remove nitrate and reduce methane (CH4) under aerobic conditions. However, the impact of copper as a cofactor in wastewater and its underlying mechanism in the AME-AD process remains unexplored. This study conducted a series of batch experiments, examining the influence of copper concentrations (ranging from 0 to 20 μM Cu2+) on denitrification, CH4 oxidation, nitrous oxide (N2O) generation, and the expressions of key functional genes within a synthetic AME-AD community. The results revealed that Cu2+ concentrations significantly affected the denitrification capacity of the AME-AD system. Specifically, the 10 μM Cu2+treatment exhibited optimal AME-AD performance, achieving a denitrification rate of 0.031 mg·h-1 and a CH4 oxidation efficiency of 98 %. However, this treatment had a high proportion of N2O generation (4.79 %), ultimately resulting in a decrease in the overall reduction of total greenhouse gases to 802.5 mg CO2-e. Moreover, the Cu2+ concentrations had a significant impact on the expression of crucial genes associated with aerobic denitrification (napA, nosZ) and CH4 oxidation (pmoA). Specifically, the highest abundance of functional genes related to denitrification was observed in 15 μM Cu2+ treatment, with napA reaching 3.75 × 1010 copies·g-1 and nosZ attaining 1.32 × 109 copies·g-1 at 192 h. Conversely, the peak pmoA copy number of 4.8 × 109 copies·g-1 was noted in 10 μM Cu2+ treatment. These discoveries enhance our comprehension of how copper modulates the AME-AD process and facilitate its application in treating low-C/N wastewater and mitigating greenhouse gas emissions.
Water Research XEnvironmental Science-Water Science and Technology
CiteScore
12.30
自引率
1.30%
发文量
19
期刊介绍:
Water Research X is a sister journal of Water Research, which follows a Gold Open Access model. It focuses on publishing concise, letter-style research papers, visionary perspectives and editorials, as well as mini-reviews on emerging topics. The Journal invites contributions from researchers worldwide on various aspects of the science and technology related to the human impact on the water cycle, water quality, and its global management.