重金属与四环素类抗生素对发光菌的毒性研究

本研究以发光细菌Photobacterium kishitanii为模式生物,通过发光抑制试验研究了5种重金属与四环素类抗生素对发光细菌的急性单一毒性与联合毒性。利用毒性单位法(TU法)表征联合毒性,并采用浓度加和模型(Concentration addtion,CA模型)与独立作用模型(Independent action,IA模型)预测二元混合体系对发光细菌的联合急性毒性。研究表明:单一毒性大小排序为硝酸铅>七水硫酸锌>氯化镉>盐酸土霉素>盐酸金霉素>盐酸强力霉素>盐酸四环素>五水硫酸铜>重铬酸钾。重金属之间的联合毒性主要表现为协同作用,重金属与四环素类抗生素的联合毒性主要表现为相加作用和拮抗作用,四环素类抗生素之间的联合毒性主要表现为拮抗作用。研究表明,重金属与四环素类抗生素共存会对发光细菌产生不同的毒性效应,因此在评价环境复合污染时应考虑联合毒性效应。

Single and combined toxicity of heavy metals and tetracyclines to luminescent bacteria

In this study, the acute single toxicity and combined toxicity of five heavy metals and tetracycline antibiotics on luminescent bacteria were studied by a luminescent test. The toxicity unit method was used to characterize the combined toxicity, and the concentration addition model and independent action model were used to predict the combined acute toxicity of the binary mixed system to luminescent bacteria. The results showed that the toxicity was in the order of Pb(NO₃)₂>ZnSO₄·7H₂O>CdCl₂·2H₂O>oxytetracycline hydrochloride> chlortetracycline hydrochloride>doxycycline hydrochloride>tetracycline hydrochloride>CuSO₄·5H₂O>K₂Cr₂O₇. The combined toxicity of heavy metals was mainly manifested as a synergistic effect. The combined toxicity of heavy metals and tetracycline antibiotics was mainly manifested as an additive and antagonistic effect, and the combined toxicity of tetracycline antibiotics was mainly manifested as an antagonistic effect. When heavy metals coexist with tetracycline antibiotics, they had different toxic effects on luminescent bacteria. Therefore, the combined toxic effects should be considered during the evaluation of combined environmental pollution.