Nitrogen input promotes denitrifying methanotrophs’ abundance and contribution to methane emission reduction in coastal wetland and paddy soil

• Published in: Environmental pollution (1987) Vol. 302; p. 119090
• Main Authors: Wang, Jiaqi, Yao, Xiangwu, Jia, Zhongjun, Zhu, Lizhong, Zheng, Ping, Kartal, Boran, Hu, Baolan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2022
• Subjects: Coastal wetland; denitrification; Denitrifying methanotrophs; methane; methane production; Methane sink; methanotrophs; nitrates; nitrites; nitrogen; nitrogen fertilizers; Nitrogen input; oxidation; paddies; Paddy soil; paddy soils; pollution; sediments; wetlands; Methane sink; Denitrifying methanotrophs; Coastal wetland; Nitrogen input; Paddy soil
• DOI: 10.1016/j.envpol.2022.119090
• ISSN: 0269-7491; 1873-6424

Denitrifying anaerobic methane oxidation (DAMO) microorganisms, using nitrate/nitrite to oxidize methane, have been proved to be an important microbial methane sink in natural habitats. Increasing nitrogen deposit around the globe brings increased availability of substrates for these microorganisms. However, how elevated nitrogen level affects denitrifying methanotrophs has not been elucidated. In this study, sediment/soil samples from coastal wetland with continuous nitrogen input and paddy field with periodic nitrogen input were collected to investigate the influence of nitrogen input on the abundance and activity of denitrifying methanotrophs. The results indicated that nitrogen input significantly promoted DAMO microorganisms’ abundance and contribution to methane emission reduction. In the coastal wetland, the contribution rate of DAMO process to methane removal increased from 12.1% to 33.5% along with continuously elevated nitrogen level in the 3-year tracking study. In the paddy field, the DAMO process accounted for 71.9% of total methane removal when nitrogen fertilizer was applied during the growing season, exceeding the aerobic methane oxidation process. This work would help us better understand the microbial methane cycle and reduce uncertainties in the estimations of the global methane emission. [Display omitted] •N input promoted the abundance and activity of denitrifying methanotrophs.•Continuous N input increased contribution of DAMO process in coastal wetland.•Periodic N input led to high DAMO microbial abundance and activity in paddy soil.•Inorganic nitrogen is a key factor that influences methane oxidation and emission.