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, National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Environ Pollut. 2020 Aug;263(Pt A):114554. doi: 10.1016/j.envpol.2020.114554. Epub 2020 Apr 11.
In recent years, antibiotic pollution has become worse, especially in China. In this study, the ecotoxicological effects of four frequently used antibiotics with different lipophilic degrees (log Kow) (sulfadiazine (SD), sulfamethazine (SM2), enrofloxacin (ENR), and norfloxacin (NOR)) at four concentrations of 1, 5, 20, and 50 mg L were examined using batch cultures of green alga Chlorella vulgaris and cyanobacterium Chrysosporum ovalisporum for 16 days based on changes in chlorophyll fluorescence parameters (chl a, Fv/Fm, and ΦPSII) and responses of the antioxidant system. Besides, the antibiotics removal efficiencies of the two microalgae were investigated. Sulfonamides (SD and SM2) had no significant inhibitory effect on the growth of C. ovalisporum, but had an inhibitory effect on C. vulgaris, whereas fluoroquinolones (ENR and NOR) significantly inhibited C. ovalisporum. The activities of superoxide dismutase, catalase, and glutathione reductase suggested that C. vulgaris was more tolerant to these antibiotics than C. ovalisporum. The increased malondialdehyde level in both algae indicated their tolerance against antibiotics. When compared with C. ovalisporum, C. vulgaris presented better capacity to remove antibiotics. In summary, the four antibiotics exerted time- or concentration-dependent ecotoxicological effects on the microalgae examined, whereas the microalgae could remove the antibiotics based on the log Kow of the antibiotics. The findings of this study contribute to effective understanding of the ecotoxicological effects of antibiotics and their removal by microalgae.
近年来，抗生素污染问题愈发严重，尤其是在中国。本研究采用浮萍（Chlorella vulgaris）和斜生栅藻（Chrysosporum ovalisporum）两种微藻，以叶绿素荧光参数（chl a、Fv/Fm 和 ΦPSII）和抗氧化系统响应为指标，研究了亲脂性不同（log Kow）的四种常用抗生素（磺胺嘧啶（SD）、磺胺甲恶唑（SM2）、恩诺沙星（ENR）和诺氟沙星（NOR））在四个浓度（1、5、20 和 50 mg·L-1）下对微藻的生态毒性效应，同时考察了两种微藻对这四种抗生素的去除效果。磺胺类（SD 和 SM2）对斜生栅藻的生长没有明显的抑制作用，但对浮萍有抑制作用，而氟喹诺酮类（ENR 和 NOR）则显著抑制斜生栅藻的生长。超氧化物歧化酶、过氧化氢酶和谷胱甘肽还原酶的活性表明，浮萍比斜生栅藻更能耐受这些抗生素。两种藻类丙二醛含量的增加表明它们对抗生素有一定的耐受性。与斜生栅藻相比，浮萍具有更好的去除抗生素的能力。综上所述，四种抗生素对所研究的微藻表现出时间或浓度依赖性的生态毒性效应，而微藻可以根据抗生素的 log Kow 去除抗生素。本研究结果有助于深入了解抗生素的生态毒性效应及其被微藻去除的机制。
