The lethal effects of some onolophosphate insecticides on yeast Saccharomyces cerevisiae.

Thre enolophosphate insecticides (chlorphenvinphos: 0-/-/2',4'-dichlorophenyl/-2-chlorovinyl/diethyl phosphate, bromphenvinphos: 0-/1-/2',4'-dichlorophenyl/-2-bromovinyl/diethyl phosphate, mebromvinphos: 0-/1-/2',4'-dichlorophenyl/-2-bromovinyl/dimethyl phosphate) have been tested for their biological activity in baker's yeast. The results indicate that the chemicals exert an immediate hibitory effect on amino acid transport system, respiration, fermentation and ell growth. Consequently the effect of precipitous cell death also occurred. Furthermore the direct destroying action of the studied chemicals on protoplast as also observed. The main cause of cell death is the development of membrane leakiness. It was found that the loss of sugar transport activity parallels the loss of cell viability. All the studied insecticides showed negligible netic activity.