College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China.
College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China.
Sci Total Environ. 2020 Sep 10;734:139499. doi: 10.1016/j.scitotenv.2020.139499. Epub 2020 May 16.
The widespread use of levofloxacin (LEV) and oxytetracycline (OTC) in hospitals and farms inevitably contributes to water pollution through waste disposal processes, municipal wastewater treatment, and manure application to farmlands, which adversely affects aquatic microorganisms. Here, we evaluated the toxicity of LEV and OTC to cyanobacteria and eukaryotic algae monocultures and freshwater microcosms. Three test cyanobacteria were inhibited by both LEV and OTC at all examined concentrations. The growth of the eukaryotic organisms C. vulgaris and Monoraphidium sp. was only inhibited by high concentrations of OTC ranging from 1000 to 10,000 μg/L; however, they were less sensitive to LEV and OTC than cyanobacteria. In the aquatic microcosms, 5 μg/L of LEV and OTC did not affect the alpha diversity of prokaryotic and eukaryotic communities or the composition of the eukaryotic microbial communities after 14 d of exposure. However, this concentration of LEV and OTC significantly changed the prokaryotic microbial community structure at the genus level, and different antibiotics affected the prokaryotic microbial community differently, suggesting that different antibiotics affect prokaryotes through different molecular mechanisms, thereby leading to differences in prokaryotic microbial growth patterns. Moreover, the changes in the prokaryotic microbial community composition suggested that low antibiotic concentrations in water could disturb prokaryotic microbial communities and cause ecological risks.
左氧氟沙星（LEV）和土霉素（OTC）在医院和农场中的广泛使用不可避免地会通过废物处理过程、城市废水处理和粪肥施用到农田中对水环境污染造成影响，从而对水生微生物产生不利影响。在这里，我们评估了 LEV 和 OTC 对蓝藻和真核藻类单培养物和淡水微宇宙的毒性。三种测试蓝藻在所有检查浓度下均受到 LEV 和 OTC 的抑制。真核生物 C. vulgaris 和 Monoraphidium sp. 的生长仅受到 1000 至 10000μg/L 的高浓度 OTC 的抑制；然而，它们对 LEV 和 OTC 的敏感性低于蓝藻。在水生微宇宙中，暴露 14 天后，5μg/L 的 LEV 和 OTC 对原核和真核生物群落的α多样性以及真核微生物群落的组成没有影响。然而，这种浓度的 LEV 和 OTC 显著改变了属水平上的原核微生物群落结构，不同的抗生素以不同的方式影响原核微生物群落，这表明不同的抗生素通过不同的分子机制影响原核生物，从而导致原核微生物生长模式的差异。此外，原核微生物群落组成的变化表明，水中低浓度的抗生素可能会干扰原核微生物群落并带来生态风险。
