Lou Xue, Xu Mengxin, Wang Mingyang, Jiang Yining, Zheng Minggang, Mu Hongyu, Liu Shuai, Kuang Shaoping, Chen Hui, Wang Zhiyao
College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, China.
College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, China; School of Environment Science and Engineering, Shandong University, Qingdao, Shandong Province, 266237, China.
Environ Res. 2025 Feb 1;266:120597. doi: 10.1016/j.envres.2024.120597. Epub 2024 Dec 9.
Ammonia oxidation, the first and rate-limiting step of nitrification, is a crucial step in nitrogen cycling. The distribution patterns of key ammonia oxidizers, including ammonia-oxidizing archaea (AOA) and bacteria (AOB), and comammox (complete ammonia oxidation) Nitrospira, provide vital insights for nitrogen cycling in natural ecosystems. Currently, the distribution and contribution of AOA, AOB and comammox Nitrospira in freshwater ecosystems remain largely underexplored. This study explored the abundances, diversity, phylogenetic characteristics, and community structures of AOA, AOB and comammox Nitrospira in the Yellow River sediments using high-throughput sequencing and qPCR. Comammox Nitrospira displayed the highest amoA gene abundance in sediments from all sampling sites compared to that of AOA and AOB. The diversity of AOA shown no significant correlations with physicochemical properties, while the diversity of AOB negatively correlated with pH (p < 0.05), and the diversity of comammox Nitrospira positively correlated with NH content and TC content (p < 0.05), respectively. Phylogenetic analysis identified Nitrososphaera, Nitrosospira, and cladeA1 as the most dominant clusters of AOA, AOB and comammox Nitrospira, respectively. The community composition of AOA, AOB, and comammox Nitrospira exhibited distinct spatial patterns, varying across the upper, middle and lower reaches. pH was the key factor shaping the community structure of AOB and comammox Nitrospira (p < 0.05), while organic carbon was the key determinant of the AOA community structure (p < 0.05). The results of this study advance our understanding of N cycling in freshwater ecosystems.
氨氧化是硝化作用的第一步和限速步骤，是氮循环中的关键环节。包括氨氧化古菌（AOA）、细菌（AOB）和全程氨氧化（comammox）硝化螺菌在内的关键氨氧化菌的分布模式，为自然生态系统中的氮循环提供了重要见解。目前，AOA、AOB和comammox硝化螺菌在淡水生态系统中的分布和贡献仍未得到充分研究。本研究采用高通量测序和qPCR技术，探究了黄河沉积物中AOA、AOB和comammox硝化螺菌的丰度、多样性、系统发育特征及群落结构。与AOA和AOB相比，comammox硝化螺菌在所有采样点沉积物中的amoA基因丰度最高。AOA的多样性与理化性质无显著相关性，而AOB的多样性与pH呈负相关（p < 0.05），comammox硝化螺菌的多样性分别与NH含量和TC含量呈正相关（p < 0.05）。系统发育分析分别确定了亚硝化球菌属、亚硝化螺菌属和A1分支为AOA、AOB和comammox硝化螺菌最主要的类群。AOA、AOB和comammox硝化螺菌的群落组成呈现出明显的空间格局，在上、中、下游有所不同。pH是塑造AOB和comammox硝化螺菌群落结构的关键因素（p < 0.05），而有机碳是AOA群落结构的关键决定因素（p < 0.05）。本研究结果增进了我们对淡水生态系统中氮循环的理解。
