During the anomalously hot summer of 2018, the water temperature in a sea cucumber culture pond reached 28–33 °C. As a result, many sea cucumbers died from the high temperature, causing huge economic losses. Currently, changes in the bacterial community of the sea cucumber culture pond ecosystem during high temperature remain largely unknown. In this study, we investigated the effects of high temperature on the community composition and function of the sea cucumber culture pond ecosystem using high-throughput sequencing. The results showed that bacterial communities in the Apostichopus japonicus intestine, surrounding water and sediment responded quickly to high temperature, as indicated by an obvious succession process of the dominant and specific bacterial community. At high temperature, the richness and diversity of the bacterial community in the water and sediment decreased significantly (P < 0.05). The richness of the bacterial community in the A. japonicus intestine was significantly increased, and several potential pathogens (Staphylococcus, Vibrio and Pseudomonas) changed in terms of their dominance, increasing the risk of disease in A. japonicus. The predictive functional profiling based on the Clusters of Orthologous Groups (COGs) database showed that the restraint of water, sediment, and the intestine bacterial community under high temperature were characterized mainly by the weakening of metabolism, environmental information processing and cellular processes, and post-translational modification, protein turnover, chaperones. The bacterial community may adapt to a high temperature by enhancing information storage and processing, amino acid transport and metabolism, and carbohydrate transport and metabolism. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database analysis, 64 KEGG pathways showed significant differences, which could be classified into six KEGG A classes and 23 KEGG B classes. The main differences in the KEGG pathways of the bacterial community in water, sediment, and A. japonicus intestine at high temperature were reflected in metabolism, cell motility, and environmental information processing. By changing its structure and group behavior, the bacterial community might be inhibited or adapted to the high temperature with both attributes dependent on changes in functional proteins and metabolic pathways. The findings of this study provide guidance for maintaining a healthy aquaculture environment.

在2018年异常炎热的夏季，海参养殖池的水温达到28-33°C。结果，许多海参因高温而死亡，造成巨大的经济损失。目前，高温期间海参养殖池生态系统细菌群落的变化仍然未知。在这项研究中，我们使用高通量测序研究了高温对海参养殖池生态系统群落组成和功能的影响。结果表明，日本刺参中的细菌群落肠道，周围的水和沉积物对高温的反应很快，这主要由特定细菌群落的明显演替过程所表明。在高温下，水体和沉积物中细菌群落的丰富度和多样性显着降低（P  <0.05）。粳稻肠中细菌群落的丰富度显着增加，并且几种潜在的病原体（葡萄球菌，弧菌和假单胞菌）的优势发生了变化，从而增加了粳稻疾病的风险。基于直系同源群（COGs）数据库的预测功能分析表明，高温下水，沉积物和肠道细菌群落的抑制作用主要表现为新陈代谢减弱，环境信息处理和细胞过程以及后期-翻译修饰，蛋白质更新，分子伴侣。细菌群落可通过增强信息存储和处理，氨基酸转运和代谢以及碳水化合物转运和代谢来适应高温。在《京都基因与基因组百科全书》（KEGG）途径数据库分析中，有64条KEGG途径表现出显着差异，可以分为6个KEGG A类和23个KEGG B类。水中细菌群落的KEGG途径的主要区别是高温下的日本肠小肠反映在代谢，细胞运动和环境信息处理中。通过改变其结构和群体行为，细菌群落可能会被抑制或适应高温，这两个属性都取决于功能蛋白和代谢途径的变化。这项研究的结果为维持健康的水产养殖环境提供了指导。