Toxicological effects of commercial cypermethrin on Chlorella pyrenoidosa
商品氯氰菊酯农药对蛋白核小球藻的毒性效应研究

The effects of commercial cypermethrin on growth, cell inclusions (soluble protein and sugar), antioxidant enzyme (superoxide dismutase, SOD) and cytotoxic product of lipid peroxidation (malondialdehyde, MDA) of Chlorella pyrenoidosa were investigated by 72 h growth tests in a batch-culture system. The growth of algal cells was inhibited by cypermethrin in a dose-dependent manner. The 72 h median effect concentration (EC50) was 4.89 mg·L-1. All biochemical parameters varied significantly within 12 h exposure, and became stable after 24 h exposure. Cellular contents of soluble protein and sugar were enhanced under the stress of cypermethrin, and the maximum magnification occurred at the moderate concentrations (3.2, 5.6 mg·L-1). SOD activity was stimulated at low concentrations (1.0, 1.8 mg·L-1) and inhibited at high concentrations (>3.2 mg·L-1). However, MDA content increased significantly with the increase of concentration. The results suggested that the inactivation of SOD and lipid peroxidation may be crucial to the growth inhibition of algal cells by cypermethrin.