铅污染对藻细胞膜电位和膜电阻的影响研究

Effects of Pb Pollution on Algae Cell Membrane Potential(MP) and Membrane Resistance(MR)

运用细胞外表面技术和电化学方法，构建了一种藻细胞膜电位传感系统，并研究了Pb^2＋污染对淡水藻细胞膜电位和膜电阻的影响。结果表明，膜电位和膜电阻两指标互为补充，快速而灵敏反应Pb^2＋对藻细胞的毒性影响，响应时间均控制在30min内，明显响应的最低浓度为0．10mmol·L^-1。本实验浓度范围内，低浓度Pb^2＋（0．10mmol·L^-1）导致藻细胞超极化、膜电阻增大；而高浓度Pb^2＋（0．20～1．00mmol·L^-1）则引起细胞去极化和膜电阻减小。此外，高浓度Pb^2＋对藻细胞膜电位、膜电阻的影响不可逆，而低浓度Pb^2＋对藻细胞的影响具有可逆性；而对比各高浓度组影响差异性，毒性剂量效应不显著，表明藻细胞对高浓度Pb^2＋具有一定抗性。

An algae membrane potential sensor based on extra-cellular technique and electrochemistry was constructed. Effects of Pb^2＋ on freshwater algae （N. flexilis） cell membrane potential （MP） and membrane resistance （MR） . Results show that MP and MR can quickly and sensitively react Pb^2＋ toxicity within 30 minutes, and that the lowest Pb^2＋ concentration of obvious reaction is 0. 10mmol · L^-1. Low concentration Pb^2＋ （0. 10mmol · L^-1） causes algae cells to significantly hyperpolarize and their MR to increase; higher concentration Pb^2＋ （0. 20- 1.00 mmol · L^-1） causes algae cells to depolarize and their MR to decrease. Moreover, the effects of higher concentration Pb^2＋ on algae cells are irreversible, while the effects of low concentration Pb^2＋ are reversible. We discover that toxic dose effect is unremarkable by comparison in different high concentration Pb^2＋ groups, which indicates algae cells can resist the toxicity of high concentration Pb^2＋.