State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, Hainan Province, 570228, China.
Hainan Academy of Ocean and Fisheries Sciences, Haikou, Hainan Province, 571126, China.
Environ Microbiol Rep. 2021 Dec;13(6):757-772. doi: 10.1111/1758-2229.13019. Epub 2021 Oct 28.
The global seagrass bed ecosystem acts as a natural ecological barrier in the littoral coastal zone. In recent years, this ecosystem has suffered from serious eutrophication and destruction caused by the continuous expansion of aquaculture. However, our understanding of the influence of aquaculture on the bacterial community remains limited. In this study, we used 16S amplicon sequencing to evaluate the impact of aquaculture feed extract solution on the composition and function of bacterial epiphytes and endophyte communities of the core seagrass from the seagrass bed ecosystem in Hainan, Thalassia hemprichii. The feed extract solution was the main factor that significantly affected the bacterial epiphyte and endophyte community structure of seagrass leaves but had no marked effect on alpha diversity was observed. Additionally, the bacterial epiphyte and endophyte community of the T. hemprichii leaves alleviated the effects of organic matter, sulfide, and nutrients caused by aquaculture wastewater. The feed extract solution promoted the proliferation of Bacteroidales, Vibrio, Desulfobulbaceae, Desulfobacteraceae, Pseudoalteromonas, Paludibacter, Marinomonas, and Pseudomonas in the leaves and root of T. hemprichii, which can effectively improve the digestibility of eutrophication. In fact, Desulfobacteraceae and Desulfobulbaceae can reduce sulfate to sulfide and oxidize sulfide to sulfur within seagrass, indicating that the increase in Desulfobulbaceae and Desulfobacteraceae facilitated the accumulation of sulfide with the treatment of feed extract solution, which may be the reason for the degradation of seagrass caused by aquaculture wastewater containing high concentrations of organic pollutants. These results suggest that although seagrass beds can withstand low concentrations of aquaculture pollutants, sulfide emissions should be minimized.
全球海草床生态系统在滨海沿海地区充当着天然生态屏障。近年来，由于水产养殖的不断扩张，该生态系统遭受了严重的富营养化和破坏。然而，我们对水产养殖对细菌群落影响的认识仍然有限。在这项研究中，我们使用 16S 扩增子测序来评估水产养殖饲料提取液对海南海草床生态系统核心海草叶表细菌附生菌和内生菌群落组成和功能的影响，其中的海草为尖瓣海莲（Thalassia hemprichii）。饲料提取液是显著影响海草叶片细菌附生菌和内生菌群落结构的主要因素，但对 alpha 多样性没有明显影响。此外，尖瓣海莲叶片的细菌附生菌和内生菌群落缓解了水产养殖废水中有机物、硫化物和养分对海草的影响。饲料提取液促进了 Bacteroidales、Vibrio、Desulfobulbaceae、Desulfobacteraceae、Pseudoalteromonas、Paludibacter、Marinomonas 和 Pseudomonas 在尖瓣海莲叶片和根部的增殖，这些细菌可以有效提高富营养化的可消化性。事实上，Desulfobacteraceae 和 Desulfobulbaceae 可以将硫酸盐还原为硫化物，并将硫化物氧化为硫，这表明在饲料提取液处理过程中，Desulfobulbaceae 和 Desulfobacteraceae 的增加促进了硫化物的积累，这可能是水产养殖废水含有高浓度有机污染物导致海草降解的原因。这些结果表明，尽管海草床可以承受低浓度的水产养殖污染物，但应尽量减少硫化物的排放。
