Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
J Basic Microbiol. 2019 Apr;59(4):425-436. doi: 10.1002/jobm.201800581. Epub 2019 Jan 9.
Ammonia oxidation, mainly driven by ammonia-oxidizing archaea (AOA) and bacteria (AOB), plays an important role in determining the rate of nitrification in riparian zones. However, the underlying factors driving the distribution and activity of AOA and AOB in riparian zones, especially in the rhizosphere of Phragmites communis remain unknown. This study revealed the dominance of AOA in ammonium oxidization with higher abundance and activity in both rhizosphere and bulk soil in summer and winter over AOB in riparian zones, based on molecular methods and double-inhibitors method. Phylogenetic analysis showed that 54d9 cluster and Nitrososphaera dominated the AOA community and Nitrosospira dominated the AOB, respectively. For the distribution of AOA and AOB, it was the spatial heterogeneity of physicochemical properties that had the most significant effect. Specifically, TOM & TC were the main physicochemical variables accounting for the difference in abundance and community composition of AOA, and TN had an important influence on AOB in the sediment/soil in riparian zones. For abundance and activity, seasonal heterogeneity and P. communis rhizosphere had a significant impact on the archaeal activity and abundance, respectively, but did not show significant influencing on AOB. These findings suggest that the small-scale environmental heterogeneities in riparian zones are important in shaping the community composition and abundance of AOA and AOB.
氨氧化作用主要由氨氧化古菌（AOA）和细菌（AOB）驱动，在决定河岸带硝化速率方面起着重要作用。然而，驱动河岸带氨氧化古菌和氨氧化细菌（AOB）分布和活性的潜在因素，特别是在香蒲根际，仍然未知。本研究基于分子方法和双抑制剂法，揭示了 AOA 在夏季和冬季河岸带氨氧化中的主导地位，其丰度和活性均高于 AOB。系统发育分析表明，54d9 聚类和硝化螺旋菌分别主导 AOA 群落和 AOB。对于 AOA 和 AOB 的分布，主要是理化性质的空间异质性对其丰度和群落组成的差异有最显著的影响。具体来说，TOM 和 TC 是解释 AOA 丰度差异的主要理化变量，而 TN 对河岸带沉积物/土壤中的 AOB 有重要影响。对于丰度和活性，季节性异质性和香蒲根际分别对古菌的活性和丰度有显著影响，但对 AOB 没有显著影响。这些发现表明，河岸带的小尺度环境异质性在塑造 AOA 和 AOB 的群落组成和丰度方面起着重要作用。
