5种取代酚化合物对淡水发光菌的联合毒性

Joint Toxicity of 5 Substituted Phenols to Freshwater Photobacteria

以新型淡水发光菌——青海弧菌Q67(Vibrio-qinghaiensissp.—Q67)为检验生物,以VeritasTM微孔板光度计为发光强度测试设备,分别测定了3,5-二羟基甲苯、2,3-二甲基苯酚、对氯苯酚、邻氯苯酚、2,4-二氯苯酚对淡水发光菌的发光抑制毒性及其混合物的联合毒性.结果表明,5种取代酚的剂量-效应关系都可用Weibull模型有效描述,从这些模型估算的半数效应浓度负对数值(-logEC50)分别为2.69、3.08、3.43、2.81和3.66,可知其对发光菌的毒性大小顺序为:2,4-二氯苯酚>对氯苯酚>2,3-二甲基苯酚>邻氯苯酚>3,5-二羟基甲苯.分别设计浓度等于各自之EC50和EC10的2个等效应浓度比混合物以及3个不同效应浓度比混合物进行联合毒性实验,结果发现,在所实验的浓度范围内各个混合物的剂量加和(DA)模型与独立作用(IA)模型具有相似的作用规律,其联合毒性既可用DA模型也可用IA模型进行预测.

Using a novel freshwater photobacteria-Vibrio-qinghaiensis sp.--Q67 as indication organism, the Veritas luminometer with 96-well microplate as testing equipment to determine luminous intensity of photobacteria, the inhibition toxicities by 5 individual substituted phenols, such as 3,5-dihydroxytoluene, 2,3-dimethylphenol, p-chlorophenol, o-chlorophenol, and 2,4- dichlorophenol, and their combined toxicities were determined, respectively. The -logECs0 values estimated from the optimal dose-response curves described by Weibull function of 5 individual substituted phenols were 2.69, 3.08, 3.43, 2.81 and 3.66 （unit of concentration： mol·L^-1） for 3,5-dihydroxytoluene, 2,3-dimethylphenol, p-chlorophenol, o-chlorophenol, and 2,4- dichlorophenol, respectively, which revealed that the toxic order among 5 phenol derivatives was 2,4-dichlorophenol 〉p- chlorophenol〉2,3-dimethylpheno〉o-chlorophenol〉3,5-dihydroxytoluene. 5 mixtures including above five substituted phenols was designed. These mixtures have either an effect-equivalent concentration ratio （EC50 or EC10） ray or a fixed concentration ratio ray （the other 3 mixtures）. The results show that there isn＇t significant difference between the joint toxicities predicted by the dose addition iDA） model and by the independent action （IA） model, which concluded that the joint toxicities of phenol mixtures could be predicted by DA or IA model.