Abstract Ammonia oxidation is an important part of the global nitrogen cycle. Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) are important players in the ammoxidation process. In this study, 13 sediment samples from the Liaohe estuary were collected in the wet season. The abundances of 16S rRNA and amoA genes were detected by real-time fluorescence quantitative PCR. The diversity and community structure of AOA and AOB were investigated by constructing clone libraries. The AOA and AOB amoA gene abundances ranged from 3.10 × 106–2.85 × 107 and 6.59 × 105–1.20 × 107 copies/g wet deposit, respectively. At all sites, AOA abundance was greater than AOB (AOA: AOB = 2.2–86.5). The ratio of AOA: archaeal 16S rRNA gene abundances and AOB: bacterial 16S rRNA gene abundances were 4.6 × 10−3–1.5 × 10−2 and 1.5 × 10−6–1.0 × 10−4. Phylogenetic analysis showed that the AOA amoA sequences were mainly Nitrosophaera and Nitrosopumilus, and most of the AOB amoA sequences belong to unclassified bacteria, which mainly were detected in estuarine sediments and wetland soils. AOA and AOB community had an obvious spatial heterogeneity. In addition, canonical correspondence analysis showed that the salinity, ammonia, total phosphorus, total organic carbon, sand, and silt content were the main driven factors of AOA and AOB community structure, in which the sand and silt content had a significant contribution.

中文翻译：

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辽河口沉积物雨季铵单加氧酶(amoA)基因丰度及群落结构

摘要 氨氧化是全球氮循环的重要组成部分。氨氧化古细菌（AOA）和氨氧化细菌（AOB）是氨氧化过程中的重要参与者。本研究在雨季采集了辽河河口沉积物样品13个。通过实时荧光定量PCR检测16S rRNA和amoA基因的丰度。通过构建克隆文库研究了AOA和AOB的多样性和群落结构。AOA 和 AOB amoA 基因丰度范围分别为 3.10 × 106–2.85 × 107 和 6.59 × 105–1.20 × 107 拷贝/g 湿沉积物。在所有地点，AOA 丰度都大于 AOB（AOA：AOB = 2.2-86.5）。AOA：古菌16S rRNA基因丰度和AOB：细菌16S rRNA基因丰度的比例为4.6×10-3-1.5×10-2和1.5×10-6-1.0×10-4。系统发育分析表明，AOA amoA 序列主要是Nitrosophaera 和Nitrosopumilus，AOB amoA 序列大部分属于未分类细菌，主要在河口沉积物和湿地土壤中检测到。AOA和AOB群落具有明显的空间异质性。此外，典型对应分析表明，盐度、氨、总磷、总有机碳、砂和粉砂含量是AOA和AOB群落结构的主要驱动因素，其中砂和粉砂含量有显着贡献。AOA和AOB群落具有明显的空间异质性。此外，典型对应分析表明，盐度、氨、总磷、总有机碳、砂和粉砂含量是AOA和AOB群落结构的主要驱动因素，其中砂和粉砂含量有显着贡献。AOA和AOB群落具有明显的空间异质性。此外，典型对应分析表明盐度、氨、总磷、总有机碳、砂和粉砂含量是AOA和AOB群落结构的主要驱动因素，其中砂和粉砂含量有显着贡献。