Nitrification inhibitor 1-octyne inhibits growth of comammox Nitrospira but does not alter their community structure in an acidic soil

• Published in: Journal of soils and sediments Vol. 23; no. 2; pp. 989 - 997
• Main Authors: Lin, Yongxin, Duan, Chunjian, Fan, Jianbo, Hu, Hang-Wei, He, Zi-Yang, Ye, Guiping, He, Ji-Zheng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2023; Springer Nature B.V
• Subjects: Abundance; Acetylene; Acidic soils; Ammonia; Ammonia-oxidizing bacteria; Archaea; Community structure; Earth and Environmental Science; Environment; Environmental Physics; Growth; Inhibitors; Laboratory experimentation; Nitrification; Nitrospira; Nucleotide sequence; Oxidation; Oxidizing agents; PCR; Sec 5 • Soil and Landscape Ecology • Research Article; Soil Science & Conservation; Soil structure; Soil testing; Soils; Nitrification inhibitor; 1-octyne; Comammox; Acidic soils; PTIO
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-022-03367-w

Purpose The compounds 1-octyne and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) are frequently used as nitrification inhibitors for ammonia-oxidizing bacteria (AOB) and archaea (AOA), respectively, but their influence on comammox Nitrospira remains unclear. In this study, we examine how will 1-octyne and PTIO influence AOA, AOB, and comammox Nitrospira in an acidic Ultisol. The results will provide guidance for the nitrification inhibitor selections in the relevant research and field management practices. Materials and methods We carried out a microcosm experiment using acetylene, 1-octyne, and PTIO as nitrification inhibitors to investigate their effects on ammonia oxidizers, especially comammox Nitrospira . The abundance of ammonia oxidizers was determined by real-time quantitative PCR while the community structure of comammox Nitrospira was examined by Illumina MiSeq sequencing. Results and discussion Acetylene, 1-octyne, and PTIO significantly reduced the net nitrification rate, with a more pronounced effect observed for acetylene and 1-octyne amendments. The addition of 1-octyne suppressed the growth of comammox Nitrospira clade A, indicating that 1-octyne was not an exclusive inhibitor for AOB in the acidic Ultisols. Moreover, PTIO reduced the abundance of AOB and comammox Nitrospira clade A, rather than that of AOA, suggesting that AOB and comammox Nitrospira were more sensitive than AOA to the PTIO inhibition in the tested soils. Acetylene, 1-octyne, and PTIO did not show observed changes to comammox Nitrospira community structure. Conclusions We provide novel evidence that 1-octyne and PTIO can significantly inhibit the growth of comammox Nitrospira , but have no significant effects on their community structure in the acidic Ultisols. Our findings have implications for proper selection of nitrification inhibitors 1-octyne and PTIO in both laboratory experiments and field practices.