Functional genes, namely hzo/hao, nirS, hzs, and ccs gene, are efficient with high specificity for detecting anammox bacteria. Sc-nirS and An-nirS primer sets were proposed for targeting Scalindua/non-Scalindua anammox bacterial groups; previously, they have not been assessed for biogeographic study on marine-terrestrial transitional systems, specifically marine and terrestrial ecosystems. Here, we report phylogenetic distribution pattern of anammox bacteria in both northern South China Sea (nSCS) and Mai Po wetland (a coastal mangrove) using nirS gene-based primers. A well-delineated biogeographic distribution pattern from ocean to continental shelf was evident by combining both gene-based analyses as previously depicted using 16S rRNA as the biomarker. Furthermore, factors affecting the abundance and composition of An-nirS genes in Mai Po wetland were identified as substrate (NO3-/NO2- concentration) and anoxic/oxic condition in association to depth. An-nirS gene abundance was from 2.6 × 103 to 1.2-1.4 × 104 copies/g dry sediment in nSCS; and it was around 5 × 103 and 1-2 × 104 copies/g dry sediment in surface and subsurface sediments of Mai Po wetland, respectively. In addition, nirS gene abundance and distribution pattern of denitrifiers and anammox bacteria in the wetland indicates a competition relationship between them. Mangrove vegetation affected the community composition of An-nirS gene considerably, and a more homogeneous distribution pattern was observed in the mangrove forest than intertidal mudflats. Sc/An-nirS gene-based biogeographic insights on anammox bacteria have shed lights on the compositional and potential functional dynamics and emphasized the importance of molecular tools on refining the current microbial ecological patterns.

中文翻译：

---

在南海北部和沿海米埔红树林湿地中，以nirS基因为靶标的厌氧菌细菌群落和组成的生物地理格局。

功能基因，即hzo / hao，nirS，hzs和ccs基因，对于检测厌氧氨氧化细菌具有很高的特异性。提出了Sc-nirS和An-nirS引物组用于靶向Scalindua /非Scalindua厌氧细菌群体。以前，尚未对它们进行海洋-陆地过渡系统（特别是海洋和陆地生态系统）的生物地理研究评估。在这里，我们报告使用基于nirS基因的引物在南海北部（nSCS）和米埔湿地（沿海红树林）中的厌氧细菌的系统发育分布模式。通过结合使用16S rRNA作为生物标记物的两种基于基因的分析，可以清楚地描述从海洋到大陆架的生物地理分布模式。此外，在米埔湿地中影响An-nirS基因丰度和组成的因素被确定为底物（NO3- / NO2-浓度）和缺氧/缺氧状况与深度相关。在nSCS中，an-nirS基因的丰度为2.6×103至1.2-1.4×104拷贝/克干沉积物。米埔湿地表层和地下沉积物的干沉积物分别约为5×103和1-2×104拷贝/ g。此外，湿地中反硝化细菌和厌氧氨氧化细菌的nirS基因丰度和分布模式表明它们之间存在竞争关系。红树林植被极大地影响了An-nirS基因的群落组成，与潮间带滩涂相比，红树林中的分布格局更为均匀。