Zhang Yu, Chen Mingming, Du Rui, Tan Ehui, Kao Shuh-Ji, Zhang Yao
State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005 China.
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Marine and Engineering, Hainan University, Haikou, 570228 China.
Mar Life Sci Technol. 2025 Jul 17;7(3):507-522. doi: 10.1007/s42995-025-00315-8. eCollection 2025 Aug.
Anaerobic ammonium oxidation (anammox) plays a critical role in nitrogen loss in estuarine and marine environments. However, the mechanisms underlying the formation and maintenance of the anammox bacterial community remain unclear. This study analyzed the anammox bacterial diversity, community structure, and interspecific relationships in three estuaries along the Chinese coastline -the Changjiang Estuary (CJE), the Oujiang Estuary (OJE), and the Jiulong River Estuary (JLE) - as well as the South China Sea (SCS) to elucidate their community assembly mechanisms. The results indicated that the anammox bacterial community exhibited the highest ammonium concentration as well as the Shannon's diversity index reflecting both species richness and evenness in the JLE. The lowest Shannon index was observed in the SCS. However, the anammox bacterial species richness was greatest in the CJE. Scalindua was the predominant anammox bacteria identified in the coastal sediments, especially in the SCS sediments. Brocadia and Kuenenia were more abundant in the estuarine sediments, particularly in JLE, than in the SCS. Phylogenetic analysis revealed distinct differentiation among Scalindua, Brocadia, and Kuenenia, with the former exhibiting a greater level of diversity. There was significant spatial heterogeneity in the anammox bacteria across the four regions, characterized by distinct distribution patterns for rare species. Low-abundance (rare) bacteria thrived in their native habitats, whereas abundant taxa displayed greater dispersal capabilities. An analysis of the community assembly mechanism suggested that ecological drift predominantly shaped the overall anammox bacterial community in the coastal sediments. Rare species were more susceptible to dispersal limitations and environmental selection. Co-occurrence network analysis identified Scalindua as a keystone genus and highlighted that rare species may play a crucial role in maintaining the ecological stability of the anammox bacterial community in coastal sediments.
The online version contains supplementary material available at 10.1007/s42995-025-00315-8.
厌氧氨氧化（anammox）在河口和海洋环境的氮损失中起着关键作用。然而，厌氧氨氧化细菌群落形成和维持的潜在机制仍不清楚。本研究分析了中国沿海三个河口——长江口（CJE）、瓯江口（OJE）和九龙江口（JLE）以及南海（SCS）的厌氧氨氧化细菌多样性、群落结构和种间关系，以阐明它们的群落组装机制。结果表明，厌氧氨氧化细菌群落在九龙江口中铵浓度最高，反映物种丰富度和均匀度的香农多样性指数也最高。在南海中观察到最低的香农指数。然而，厌氧氨氧化细菌的物种丰富度在长江口中最大。斯氏菌属（Scalindua）是在沿海沉积物中鉴定出的主要厌氧氨氧化细菌，特别是在南海沉积物中。布罗卡德氏菌属（Brocadia）和库氏菌属（Kuenenia）在河口沉积物中比在南海中更为丰富，尤其是在九龙江口中。系统发育分析揭示了斯氏菌属、布罗卡德氏菌属和库氏菌属之间的明显分化，前者表现出更高的多样性水平。四个区域的厌氧氨氧化细菌存在显著的空间异质性，其特征是稀有物种具有独特的分布模式。低丰度（稀有）细菌在其原生栖息地中茁壮成长，而丰富的分类群表现出更大的扩散能力。对群落组装机制的分析表明，生态漂变主要塑造了沿海沉积物中的整体厌氧氨氧化细菌群落。稀有物种更容易受到扩散限制和环境选择的影响。共现网络分析确定斯氏菌属为关键属，并强调稀有物种可能在维持沿海沉积物中厌氧氨氧化细菌群落的生态稳定性方面发挥关键作用。
在线版本包含可在10.1007/s42995-025-00315-8获取的补充材料。
