The Toxic Effects of the Surfactant CTAC and STAB on Chlorella pyrenoidosa

The acute toxicity of cetanecyl trimethyl ammonium chloride(CTAC)and stearyl trimethyl ammonium bromide(STAB)to Chlorel-la pyrenoidosa were investigated.The growth rate,superoxide dismutase(SOD)activities and the contents of protein,chlorophyll and malon-dialdehyde(MDA)in algae were monitored to determine toxicity from surfactant exposure.Although a decrease in growth of algae was ob-served in both treatments,STAB caused more sever stress to Chlorella pyrenoidosa than CATC.The contents of proteins and chlorophyll and SOD activities in algae gradually increased during the first 4-days exposure,while the contents of MDA in algae showed a completely dissimi-lar response.According to the five kinds of indicators changes,the time-response and dose-response suggested that the surfactant first hurt in Chlorella pyrenoidosa was damaging membrane by changing membrane lipid molecules soluble.And primary mechanism on Chlorella pyrenoidosa cells might be related to the oxidation damage of lipid and other biological large molecules caused by CTAC and STAB.