title: pH-dominated niche segregation of ammonia-oxidising microorganisms in Chinese agricultural soils.
abstract: Ammonia-oxidising archaea (AOA) are increasingly recognised as the primary mediators of soil ammonia oxidation, particularly in acidic soils. To explore the niche segregation of AOA and ammonia-oxidising bacteria (AOB) and the potential effect of this segregation on nitrification rates and the nitrogen cycle in Chinese agricultural soils, AOA and AOB amoA gene databases were established, and 454 high-throughput sequencing was used to investigate the key factors leading to the niche segregation of these two types of microorganisms. qPCR results demonstrated that there were more functional genes for AOA than for AOB in most of the soils. AOA diversity was higher than AOB diversity in most of the soils with AOA operational taxonomic units (OTU) numbers ranging from 40 to 169 and AOB OTU numbers ranging from 18 to 105. pH was the most important factor influencing the community structure of AOA (P < 0.01) and AOB (P < 0.05), and acidophilic AOA (i.e. Nitrosotalea-related sequences) were dominant in soils with pH values below 6.0. In addition, AOA amoA gene copy numbers were significantly positively correlated with pH (P < 0.05), the ratio of AOA OTU numbers/AOB OTU numbers was significantly negatively correlated with pH (P < 0.05), and the percentage of sequences represented by the Nitrosotalea cluster was significantly negatively correlated with pH (P < 0.01).
authors: Department of Environmental Engineering, Zhejiang University, Hangzhou, China.
authors: Hu
authors: H
authors: Baolan
authors: Liu
authors: L
authors: Shuai
authors: Wang
authors: W
authors: Wei
authors: Shen
authors: S
authors: Lidong
authors: Lou
authors: L
authors: Liping
authors: Liu
authors: L
authors: Weiping
authors: Tian
authors: T
authors: Guangming
authors: Xu
authors: X
authors: Xiangyang
authors: Zheng
authors: Z
authors: Ping
mesh_terms: D000383:Agriculture; D000641:Ammonia / Q000378:metabolism*; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002681:China; D008969:Molecular Sequence Data; D058465:Nitrification; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D012987:Soil; D000641:Ammonia
keywords: Chinese agricultural soils; ammonia-oxidising archaea; ammonia-oxidising bacteria; high-throughput sequencing; niche segregation