Ecotoxicity and interacting mechanism of anionic surfactant sodium dodecyl sulfate (SDS) and its mixtures with nonionic surfactant fatty alcohol-polyoxyethlene ether (AEO)
Ecotoxicity and interacting mechanism of anionic surfactant sodium dodecyl sulfate (SDS) and its mixtures with nonionic surfactant fatty alcohol-polyoxyethlene ether (AEO)
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阴离子表面活性剂十二烷基硫酸钠(SDS)及其与非离子表面活性剂脂肪醇聚氧乙烯醚(AEO)混合物的生态毒性及相互作用机制
DOI：
10.1016/j.aquatox.2020.105467
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发表时间：
2020-05-01
影响因子：
4.5
通讯作者：
Shi, Bi
中科院分区：
文献类型：
--
作者：
Han, Weimo;Hou, Mengchun;Shi, Bi
本文报道了阴离子十二烷基硫酸钠（SDS）和非离子脂肪醇聚氧乙烯醚（AEO）二元表面活性剂混合物对发光菌（Photobacterium phosphoreum）的毒性。通过光谱探测SDS诱导未折叠的牛血清白蛋白（BSA）的重折叠和基于Rubingh模型从临界胶束浓度理论计算混合表面活性剂的相互作用参数，阐明了毒性相互作用的关键作用。根据对AEO比例的毒性反应，SDS/AEO混合物可分为两组：第一组为AEO质量比较低的SDS：AEO = 4：1、3：1;第二组为AEO质量比较高的SDS：AEO = 3：2、1：1、2：3、1：4。SDS/AEO混合物的毒性随第I组AEO比例的增加而降低，当AEO比例增加到第II组时略有波动。质量比为1：1的混合物的毒性略高于第II组中的其他混合物。扫描电子显微镜（SEM）图像表明，AEO的加入阻碍了SDS对细胞膜的作用。荧光测定表明，AEO可提取包埋在BSA基质中的SDS分子（与BSA高活性位点结合的SDS分子除外），并使未折叠的蛋白逐步重折叠。结果与SDS/AEO混合物的比例依赖性毒性非常相似，表明混合胶束的形成起着关键作用。相互作用参数进一步显示，拮抗作用导致等质量比（1：1）的混合物在组II中显示出比其他质量比更高的毒性。这些结果可用于配制SDS/AEO混合物在应用中的高效和环保。
This paper reports the proportion-dependent toxicity of binary surfactant mixtures containing anionic sodium dodecyl sulfate (SDS) and nonionic fatty alcohol-polyoxyethlene ether (AEO) toward Photobacterium phosphoreum. The crucial role of toxicity interactions was elucidated by spectroscopic probing the refolding of the unfolded bovine serum albumin (BSA) induced by SDS and theoretical calculating the interaction parameter of mixed surfactants based on Rubingh's model from the critical micelle concentrations. The SDS/AEO mixtures can be divided into two groups based on the toxicity response to the proportion of AEO in the mixtures: Group I contained low mass proportions of AEO, that is, SDS:AEO = 4:1, 3:1; Group II featured high AEO proportions, that is, SDS:AEO = 3:2, 1:1, 2:3, 1:4. The toxicity of SDS/AEO mixtures decreased with the enhanced proportion of AEO in Group I and then fluctuated slightly when the AEO proportion increased to that of Group II. The mixture with the mass ratio of 1:1 showed a slightly higher toxicity than the others in Group II. Scanning electron microscopy (SEM) images illustrated that the addition of AEO hindered the action of SDS against the cell membrane. Fluorescence measurement indicated that AEO could extract SDS molecules embedded in the BSA matrix, except for those bound to the highly active sites of BSA, and refold stepwise the unfolded protein. The results were in excellent analogy to the proportion-dependent toxicity of SDS/AEO mixture, indicating the formation of mixed micelles playing a key role. The interaction parameter further revealed that antagonism led to the mixture with equal mass ratio (1:1) showing higher toxicity than other mass ratios in Group II. These results can be useful for compounding SDS/AEO mixtures in application efficiently and eco-friendly.