State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, People's Republic of China.
Environ Pollut. 2021 Jul 1;280:116998. doi: 10.1016/j.envpol.2021.116998. Epub 2021 Mar 21.
Naturally present aquatic microorganisms play an important role in water purification systems, such as the self-purification of surface waters. In this study, two water sources representing polluted surface water (Olympic Green; OG) and unpolluted surface water (Jingmi river; JM), were used to explore the self-purification of surface water by bacteria under different environmental conditions. The dominant bacterial community of OG and JM waters (both are Firmicutes and Proteobacteria) were isolated, cultured, and then used to carry out flocculation tests. Results showed that the flocculation ability of the dominant bacteria and extracellular polymeric substances (EPS) obtained from OG isolation was significantly greater than that from JM. Further examination illustrated that the main components of EPS were polysaccharides, which played an important role in improving the flocculation ability of bacteria. EPS from dominant cultural bacteria strains (OG1 and JM3) isolated from the two different sources lacked hydrophilic groups (e.g. COOH) and had a networked structure which are the main reasons to enhance the flocculation ability. The bacterial diversity and redundancy analysis (RDA) results also showed that microbial community composition is determined by water quality (SS, TOC, and NH), and different Bacteroidetes, Actinobacteria and Proteobacteria community structures can improve the water body's ability to remove environmental pollutants (such as SS, humic acid and fulvic acid). These findings provide new information showing how bacterial communities change with environmental factors while maintaining the purity of surface water.
天然存在的水生微生物在水净化系统中发挥着重要作用，例如地表水的自净作用。在这项研究中，我们使用了两个代表受污染地表水（奥林匹克森林公园，OG）和未受污染地表水（京密引水渠，JM）的水源，以探索在不同环境条件下细菌对地表水的自净作用。我们分离、培养了 OG 和 JM 水样中的优势菌群（均为厚壁菌门和变形菌门），然后进行了絮凝试验。结果表明，OG 水样中优势菌及其提取的胞外聚合物（EPS）的絮凝能力明显大于 JM 水样。进一步的研究表明，EPS 的主要成分是多糖，这对于提高细菌的絮凝能力起着重要作用。从两个不同来源分离的优势培养菌（OG1 和 JM3）的 EPS 缺乏亲水基团（如 COOH），且具有网状结构，这是增强絮凝能力的主要原因。细菌多样性和冗余分析（RDA）结果还表明，微生物群落组成取决于水质（SS、TOC 和 NH），不同的拟杆菌门、放线菌门和变形菌门的群落结构可以提高水体去除环境污染物（如 SS、腐殖酸和富里酸）的能力。这些发现提供了新的信息，表明在保持地表水纯净的同时，细菌群落如何随环境因素而变化。
