Zhao Ze, Zhang Lu, Zhang Guoqing, Gao Han, Chen Xiaogang, Li Ling, Ju Feng
College of Environmental & Resources Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang 310024, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, Zhejiang 310030, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang 310024, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, Zhejiang 310030, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
Water Res. 2023 Aug 15;242:120236. doi: 10.1016/j.watres.2023.120236. Epub 2023 Jun 16.
Tidal hydrodynamics drive the groundwater-seawater exchange and shifts in microbiota structure in the coastal zone. However, how the coastal water microbiota structure and assembly patterns respond to periodic tidal fluctuations and anthropogenic disturbance remains unexplored in the intertidal groundwater-surface water (GW-SW) continuum, although it affects biogeochemical cycles and coastal water quality therein. Here, through hourly time-series sampling in the saltmarsh tidal creek, rhythmic patterns of microbiota structure in response to daily and monthly tidal fluctuations in intertidal surface water are disentangled for the first time. The similarity in archaeal community structures between groundwater and ebb-tide surface water (R=0.06, p = 0.2) demonstrated archaeal transport through groundwater discharge, whereas multi-source transport mechanisms led to unique bacterial biota in ebb-tide water. Homogeneous selection (58.6%-69.3%) dominated microbiota assembly in the natural intertidal GW-SW continuum and the presence of 157 rhythmic ASVs identified at ebb tide and 141 at flood tide could be attributed to the difference in environmental selection between groundwater and seawater. For intertidal groundwater in the tidal creek affected by anthropogenically contaminated riverine inputs, higher microbial diversity and shift in community structure were primarily controlled by increased co-contribution of dispersal limitation and drift (jointly 57.8%) and enhanced microbial interactions. Overall, this study fills the knowledge gaps in the tide-driven water microbial dynamics in coastal transition zone and the response of intertidal groundwater microbiota to anthropogenic pollution of overlying waters. It also highlights the potential of microbiome analysis in enhancing coastal water quality monitoring and identifying anthropogenic pollution sources (e.g., pathogenic Vibrio in aquaculture) through the detection of rhythmic microbial variances associated with intertidal groundwater discharge and seawater intrusion.
潮汐水动力驱动着海岸带的地下水-海水交换以及微生物群落结构的变化。然而，尽管潮间带地下水-地表水（GW-SW）连续体中的海岸水微生物群落结构和组装模式对周期性潮汐波动和人为干扰的响应会影响其中的生物地球化学循环和海岸水质，但目前仍未得到充分研究。在此，通过对盐沼潮汐小溪进行每小时一次的时间序列采样，首次解析了潮间带地表水微生物群落结构对每日和每月潮汐波动的节律模式。地下水与落潮水表面水之间古菌群落结构的相似性（R=0.06，p=0.2）表明古菌通过地下水排放进行传输，而多源传输机制导致落潮水中存在独特的细菌生物群。在天然潮间带GW-SW连续体中，均匀选择（58.6%-69.3%）主导着微生物群落的组装，落潮时识别出的157个节律性ASV和涨潮时的141个ASV的存在可归因于地下水和海水之间环境选择的差异。对于受人为污染的河流输入影响的潮汐小溪中的潮间带地下水，较高的微生物多样性和群落结构变化主要受扩散限制和漂移共同贡献增加（合计57.8%）以及微生物相互作用增强的控制。总体而言，本研究填补了海岸过渡带潮汐驱动的水体微生物动力学以及潮间带地下水微生物群对上层水体人为污染响应方面的知识空白。它还强调了微生物组分析在加强海岸水质监测以及通过检测与潮间带地下水排放和海水入侵相关的节律性微生物变化来识别人为污染源（如水产养殖中的致病性弧菌）方面的潜力。
