Antibiotic contaminants could promote the formation of harmful cyanobacterial blooms through hormetic stimulation, but the mechanisms underlying these stimulatory effects remain unclear. This study investigated the biochemical, transcriptomic, and proteomic responses of a dominant bloom-forming cyanobacterium, Microcystis aeruginosa, to a five-component mixture of frequently detected antibiotics at current contamination levels. The growth rate of M. aeruginosa presented a U-shaped dose-response to 50–500 ng L^-1 of mixed antibiotics. Alterations in the transcriptome of M. aeruginosa suggested the excitation of both photosynthesis and carbon metabolism, increasing energy generation in response to oxidative stress induced by low-dose antibiotics, and thus contributing to the significant (p < 0.05) increase in growth rate, F_v/F_m, and cell density. Comparison between transcriptomic and proteomic responses further confirmed the action mode of the mixed antibiotics. Proteins and their corresponding genes related to ROS scavenging, photosynthesis, carbon fixation, electron transport, oxidative phosphorylation, and biosynthesis, showed consistent expression tendencies in response to 200 ng L^-1 of mixed antibiotics, which were credible action targets of mixed antibiotics in M. aeruginosa. Mixed antibiotics stimulated microcystin synthesis by upregulating a microcystin synthetase and its encoding gene (mcyC), which could increase the hazard of M. aeruginosa in aquatic environments.

抗生素污染物可以通过兴奋刺激促进有害蓝藻水华的形成，但这些刺激作用背后的机制仍不清楚。本研究调查了主要的水华形成蓝藻铜绿微囊藻对当前污染水平下经常检测到的抗生素的五组分混合物的生化、转录组和蛋白质组学反应。M. aeruginosa的生长速率对50-500 ng L ^-1的混合抗生素呈U形剂量反应。绿脓杆菌转录组的变化表明光合作用和碳代谢的激发，增加能量产生以响应低剂量抗生素诱导的氧化应激，从而促进生长速率、F _v / F _m和细胞密度的显着增加 ( p < 0.05) . 转录组和蛋白质组反应的比较进一步证实了混合抗生素的作用模式。与 ROS 清除、光合作用、碳固定、电子传递、氧化磷酸化和生物合成相关的蛋白质及其相应基因在响应 200 ng L ^-1的混合抗生素时表现出一致的表达趋势，这是混合抗生素在绿脓杆菌。混合抗生素通过上调微囊藻毒素合成酶及其编码基因 ( mcy C) 来刺激微囊藻毒素合成，这可能会增加水生环境中铜绿假单胞菌的危害。