Antibiotic contaminants have the potential to interfere with the control of cyanobacterial bloom through generating hormesis in cyanobacteria at current contamination level of ng L-1. This study investigated the influence of a mixture of four frequently detected antibiotics, amoxicillin, ciprofloxacin, sulfamethoxazole and tetracycline, during the treatment of Microcystis aeruginosa by copper sulfate (CuSO4) algaecide. CuSO4 significantly (p <  0.05) inhibited cell density, growth rate, Fv/Fm value, chlorophyll a content and microcystin production ability of M. aeruginosa in a dose-dependent manner at application doses of 0.01-0.05 mg L-1. Besides, CuSO4 inhibited oxidation-reduction process, photosynthesis and biosynthesis in M. aeruginosa at the proteomic level. Preventative application of CuSO4 to a low density (4 × 105 cells mL-1) of M. aeruginosa effectively prevented the formation of bloom at low CuSO4 doses, which is a possible route for eliminating the negative effects of CuSO4 algaecide in aquatic environments. The presence of mixed antibiotics alleviated the toxicity of CuSO4 in M. aeruginosa, through the downregulation of cation transport proteins and the upregulation of proteins related with chlorophyll a synthesis, photosynthesis, gene expression and oxidation-reduction. Mixed antibiotics also promoted microcystin synthesis in CuSO4 treated cells through the upregulation of microcystin synthetases. Mixed antibiotics significantly (p <  0.05) increased cell density, growth rate, Fv/Fm value, chlorophyll a content and microcystin production ability in CuSO4 treated cells at test concentrations of 80 and 200 ng L-1. A no-impact threshold of 20 ng L-1 for mixed antibiotics (5 ng L-1 for each antibiotic) was suggested for eliminating the interference of antibiotic contaminants on cyanobacterial bloom control.

中文翻译：

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在CuSO4处理期间，抗生素诱导了铜绿微囊藻的细胞密度，光合作用，微囊藻毒素合成和蛋白质组学表达的变化。

抗生素污染物有可能通过在当前ng L-1污染水平下在蓝细菌中产生兴奋剂而干扰蓝细菌水华的控制。这项研究调查了四种常见的抗生素混合物（阿莫西林，环丙沙星，磺胺甲恶唑和四环素）在用硫酸铜（CuSO4）杀藻剂处理铜绿微囊藻中的影响。在0.01-0.05 mg L-1的施用剂量下，CuSO4剂量依赖性地显着（p <0.05）抑制铜绿假单胞菌的细胞密度，生长速率，Fv / Fm值，叶绿素a含量和微囊藻毒素生产能力。此外，CuSO4在蛋白质组学水平上抑制了铜绿假单胞菌的氧化还原过程，光合作用和生物合成。预防性地将CuSO4应用于低密度（4×105细胞mL-1）的M. 铜绿假单胞菌可有效防止低剂量CuSO4形成水华，这是消除CuSO4除藻剂在水生环境中产生负面影响的可能途径。混合抗生素的存在通过下调阳离子转运蛋白和上调与叶绿素a合成，光合作用，基因表达和氧化还原有关的蛋白，减轻了铜绿假单胞菌中CuSO4的毒性。混合抗生素还通过上调微囊藻毒素合成酶来促进CuSO4处理的细胞中微囊藻毒素的合成。在浓度为80和200 ng L-1的CuSO4处理的细胞中，混合抗生素显着（p <0.05）增加了细胞密度，生长速度，Fv / Fm值，叶绿素a含量和微囊藻毒素生产能力。