Effect of combined pollution of three antibiotics and Cu on soil catalase activity

• Main Authors: ZHANG Wen-jie, YANG Li-li, WANG Jin-hua, ZHU Lu-sheng, WANG Jun, MAO Shu-shuai
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2020-01-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: enrofloxacin, oxytetracycline, sulfamethazine, cu, soil catalase
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2020/1/20200117.htm

To analyze the single and joint toxicity of antibiotics and heavy metals on the soil catalase ecosystem, this study regarded three kinds of antibiotics, enrofloxacin(ENR), oxytetracycline(OTC), and sulfamethazine(SM2), and Cu as target contaminants. Potassium permanganate titration was used to study the effects of these contaminants on the activity of catalase, which is an important indicator of soil pollution. The results showed that the treatment of medium and low concentrations of ENR had a certain activation effect on enzyme activity, and the maximum activation rate was 5.52%. With the increase of exposure concentration, the inhibitory effect of OTC on enzyme activity increased, and the inhibition rate increased to 8.36%. At the initial stage of SM2 treatment, the medium and low concentration treatment group activated the enzyme, and the maximum activation rate reached 7.46%. After treatment for 21 d, The high concentration treatment group activated the enzyme on day 21, and the activation rate was 1.71%. Cu inhibited catalase activity on day 28. The effect of ENR+Cu treatment on catalase activity was firstly inhibited and then activated with the increase of pollution concentration; on day 7 of the OTC+Cu treatment, all the concentration groups had no significant difference with the control, and after 14 d, the high concentration group inhibited soil catalase activity with the highest inhibition rate of 3.58%. The SM2+Cu treatment groups had an inhibition effect following the activation effect, with an activation rate of 10.00% on day 7 and an inhibition rate of 4.49% on day 28. During the entire experimental cycle, the ENR+Cu and SM2+Cu treatment groups were affected by concentration and time; antagonism dominated the OTC+Cu composite pollution effects. All the findings in this study demonstrated that in the case of a single pollutant, the effect of antibiotics on soil catalase was related to its type, exposure concentration, and exposure time. With a combination of pollutants, the interaction between antibiotics and Cu varied, and was characterized by antagonistic and synergistic effects, which were related to the type of antibiotic, ratio of combined pollution concentration and exposure time, and the ratio of antibiotic and Cu coordination reactions to produce complexes.