Niche Differentiation of Comammox Nitrospira in the Mudflat and Reclaimed Agricultural Soils Along the North Branch of Yangtze River Estuary

作者：Xinxin Wang, Lu Lu, Xue Zhou, Xiufeng Tang, Lu Kuang, Junhui Chen, Jun Shan, Huijie Lü, Hua Qin, Jonathan M. Adams, Baozhan Wang · 发表于：Frontiers in Microbiology · 年份：2021 · DOI：10.3389/fmicb.2020.618287 · 被引用次数：45 · 研究领域：Wastewater Treatment and Nitrogen Removal、Microbial Community Ecology and Physiology、Constructed Wetlands for Wastewater Treatment

The discovery of complete ammonia oxidation (comammox), oxidizing ammonia to nitrate via nitrite in a single organism, has redefined the traditional recognition of the two-step nitrification driven by two functional groups (ammonia-oxidizing and nitrite-oxidizing microorganisms). However, the understanding of the distribution and niche differentiation of comammox Nitrospira in the estuarine mudflats and their reclaimed agricultural soils is still limited. Here, we investigated the abundance, diversity and community structures of comammox Nitrospira in the mudflats and the reclaimed agricultural soils in the northern Yangtze River estuary. Quantitative PCR showed the abundances of amoA genes of comammox were lower than that of ammonia-oxidizing bacteria (AOB) in nearly all samples. Amplicon sequencing of amoA genes revealed that the community structures of comammox Nitrospira were significantly ( P < 0.001) different between the original mudflats and the reclaimed agricultural soils, indicating niche differentiation among comammox Nitrospira clades (clade A.1, clade A.2, and clade B). The clade A.1 was the dominant group of comammox Nitrospira in the mudflats, while clade B predominated in the agricultural soils. However, the members of clade A.2 could be clearly divided into two groups, the mudflat-preferred and agricultural soil-preferred groups, suggesting more complicated ecological preferences within this sub-clade. Furthermore, it was demonstrated that salinity, o...