Centre for Research on Environmental Ecology and Fish Nutrient of the Ministry of Agriculture, Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
Centre for Research on Environmental Ecology and Fish Nutrient of the Ministry of Agriculture, Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
J Environ Sci (China). 2020 Nov;97:141-148. doi: 10.1016/j.jes.2020.05.018. Epub 2020 Jun 10.
Sulfonamides (SAs) are common antimicrobial drugs, which are frequently detected in surface water systems, and are difficult to degrade, posing a potential threat to the aquatic environment. However, little is known about the potential adverse effects of SAs on non-target organisms (e.g., microalgae) in the aquatic ecosystem. In this study, the effect of SAs (sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) at 1, 5, 20, and 50 mg/L concentrations, respectively) on the freshwater microalga Dictyosphaerium sp. was investigated, with respect to changes of biomass and chlorophyll a content and induction of extracellular polymer substances (EPS), including protein and polysaccharide contents. At the same time, the residue of SAs was determined. The results showed that Dictyosphaerium sp. was tolerant to the three SAs, and the chlorophyll a content in Dictyosphaerium sp. significantly decreased on day 7, followed by a "compensation phenomena". The increase in protein and polysaccharide contents played a defensive role in Dictyosphaerium sp. against antibiotic stress, and there was a strong positive correlation between polysaccharide contents and antibiotic concentrations. Dictyosphaerium sp. exhibited 35%-45%, 30%-42%, and 26%-51% removal of SD, SM1, and SM2, respectively. This study is helpful to understand the changes of EPS in the defense process of microalgae under the action of antibiotics, and provides a new insight for the ecological removal of antibiotic pollution in natural surface water system.
磺胺类药物（SAs）是常见的抗菌药物，经常在地表水系统中被检测到，而且难以降解，对水生环境构成潜在威胁。然而，对于磺胺类药物对水生生态系统中非目标生物（如微藻）的潜在不良影响知之甚少。在本研究中，研究了磺胺类药物（磺胺嘧啶（SD）、磺胺甲噁唑（SM1）和磺胺二甲嘧啶（SM2），浓度分别为 1、5、20 和 50 mg/L）对淡水微藻Dictyosphaerium sp.的影响，包括生物量和叶绿素 a 含量的变化以及细胞外聚合物物质（EPS）的诱导，包括蛋白质和多糖含量。同时，测定了磺胺类药物的残留量。结果表明，Dictyosphaerium sp.对三种磺胺类药物具有耐受性，Dictyosphaerium sp. 的叶绿素 a 含量在第 7 天显著下降，随后出现“补偿现象”。蛋白质和多糖含量的增加在 Dictyosphaerium sp. 对抗抗生素胁迫中发挥了防御作用，多糖含量与抗生素浓度之间存在很强的正相关关系。Dictyosphaerium sp.对 SD、SM1 和 SM2 的去除率分别为 35%-45%、30%-42%和 26%-51%。本研究有助于了解抗生素作用下微藻防御过程中 EPS 的变化，为自然地表水系统中抗生素污染的生态去除提供了新的见解。
