十六烷基三甲基溴化铵对蛋白核小球藻的毒性效应

Toxic effects of the cetyltrimethylammonium bromide on Chlorella pyrenoidosa

以蛋白核小球藻为受试物,分别设0(CK)、0.06、0.12、0.18、0.24、0.30、0.36 mg/L十六烷基三甲基溴化铵(CTAB)处理,考察CTAB对藻生长和生化指标的影响,分析其致毒机理。结果表明:CTAB对蛋白核小球藻96 h EC50值为0.17 mg/L;藻细胞叶绿素a、水溶性蛋白质含量及超氧化物歧化酶(SOD)活性随CTAB浓度增加呈先升后降趋势,当CTAB剂量≤0.06 mg/L时,叶绿素a含量略微上升,>0.06 mg/L时,叶绿素a含量急剧下降;CTAB剂量≤0.24 mg/L处理下蛋白质含量增加,CTAB剂量≥0.30 mg/L处理时水溶性蛋白含量低于对照组;除剂量≤0.06 mg/L处理外,SOD活性随CTAB剂量的增大呈下降趋势;脂质过氧化丙二醛(MDA)含量则随CTAB浓度增加逐渐上升;CTAB对蛋白核小球藻的致毒机理为通过破坏细胞膜完整性,抑制SOD活性,导致MDA含量持续上升。

The toxicity of cetyltrimethylammonium bromide（CTAB） on the growth and biochemical indicators of algae was studied by taking Chlorella pyrenoidosa as the test organism.The results showed that 96 h EC50 of CTAB on Chlorella pyrenoidosa was 0.17 mg/L;algal chlorophyll,protein content and Superoxide Dismutase（SOD） activity first increased and then decreased,the content of algal chlorophyll and activity of SOD rose slightly in low concentrations of CTAB（≤0.06 mg/L） and decreased dramatically in a higher concentration（0.06 mg/L）;when the dosage of CTAB≤0.24 mg/L,the protein content increased,however it decreased obviously with a higher addition of CTAB（≥0.30 mg/L）;lipid peroxidation malondialdehyde（MDA） content rose gradually with the increase of CTAB concentrations.According to 5 kinds of active parameter variation rules and the measured results of algal cell apoptosis by flow cytometric apparatus,it was speculated that CTAB first destroyed the integrity of the cell membrane,thereby inhibited the SOD activity,leading to the MDA content rising continually.Therefore,the restrained SOD activity leading to peroxidation of the membrane lipid may be the main reason CTAB causes toxicity on Chlorella pyrenoidosa.