Combined toxicity of sequential exposure of antibiotics and fungicides on green algae [抗生素与杀菌剂顺序暴露对绿藻的联合毒性]

作者：Li C.-J.; Nong Q.-Y.; Qin L.-T.^*; Mo L.-Y.; Liang Y.-P.; Zeng H.-H.; Deng Z.-G.; Liu L.

来源：China Environmental Science, 2023, 43(1): 404-414.

• antibiotic
• Chlorella pyrenoidosa
• combined toxicity
• sequential exposure
• triazole fungicides

The mixture systems of three antibiotics (doxycycline hydrochloride (DOX), erythromycin (ERY), oxytetracycline (OXY)) and three triazole fungicides (myclobutanil(MYC), propiconazole (PRO) and tebuconazole (TCZ)) were selected as target pollutants. The primary producer green algae (Chlorella pyrenoidosa) in the ecosystem was used as the test organism to study the combined toxicity of sequential exposure to target contaminants. The results showed that the inhibitory toxicities of six single target pollutants to Chlorella pyrenoidosa were: PRO>DOX>TCZ>ERY>MYC>OXY. The difference of inhibition rates between simultaneous exposure and sequential exposure of antibiotic triazole bactericide mixture system mixed at 50% effect concentration was 0.38%~36.76%. The toxicity to Chlorella pyrenoidosa increased up to 36.82% when DOX, PRO, TCZ, and MYC were exposed to Chlorella pyrenoidosa in the reverse order. Under the influence of different concentrations and time, the sequential exposure toxicities of PRO-DOX and TCZ-DOX were higher than that of DOX-PRO and DOX-TCZ after adjusting the exposure sequence. The higher concentrations the greater difference of inhibition rates. At the exposure time of 96h~144h, the difference of sequential exposure inhibition rates of exposure concentration EC50/20 was 0.65%~11.57%. The difference of sequential exposure inhibition rates of exposure concentration EC50 was 0.15%~36.93%. The range of sequential exposure inhibition rate increased with the increase of concentration. At the exposure concentration EC50/20 to EC50, the difference of sequential exposure inhibition rates of exposure time 96h was 0.29%~36.93%. The difference of sequential exposure inhibition rates of exposure time 144h was 0.215%~30.09%. The range of sequential exposure inhibition rate decreased with the increase of time. Therefore, sequential exposure changed the combined toxicity of antibiotics and triazole fungicides to Chlorella pyrenoidosa. The sequential exposure, exposure time, and exposure concentration were the key factors affecting the toxicity.

• 单位
  桂林理工大学