Toxicity of cadmium to twoStreptomyces species as affected by clay minerals

Summary The effect of cadmium on the growth ofStreptomyces rimosus andS. bottropensis (both isolated from soil) was investigated. The modifying effect of the presence of the clay minerals kaolinite, bentonite and vermiculte on Cd toxicity was also included. After four days no growth was observed at 100 ppm CdCl₂ ofS. bottropensis and at 150 ppm in case ofS. rimosus. After six days some growth ofS. rimosus occurred at 150 ppm CdCl₂ and ofS. bottropensis at 100 ppm. Addition of the three clay minerals decreased the Cd toxicity considerably.