COMPARATIVE EVALUATION OF SENSITIVITY OF DIFFERENT TEST FUNCTIONS OF SACCHAROMYCES CEREVISIAE TO SALTS OF HEAVY METALS

The yeast Saccharomyces cerevisiae are convenient eukaryotic model to determining the toxicity of various pollutants, including heavy metals. Most of biotests with the use yeast are based on the determination of the cytotoxic or genotoxic effect of heavy metals. These methods are time consuming, require special laboratory equipment. For develop of new rapid test-reaction used the ability of baker’s yeast S. cerevisiae, as a yeast of fermentation, was used to form a foam on the surface of the fermentation liquid. To conduct the bioassay used a commercial preparation of dry yeast “SAF-Moment” (LLC “SAF-Neva”, Russian Federation), as a fermentable substrate - 2% glucose solution. The toxic effect of heavy metal salts was determined by the suppression of foaming in a yeast suspension after incubation for 15 min. In parallelevaluated the influence of salts of heavy metals on the growth and survival of yeast. Foaming activity of theyeast was more sensitive to the tested toxicants in comparison with the growth function ofyeastand their survival. Mercury chloride exerted a toxic effect on the foaming in the yeast suspension in a concentration of 0,0001, sulfateof copper, chlorideof cadmium, chlorideof cobalt 0,001, sulfateof lead 0,01, sulfateof iron 0,1, sulfateof zinc 1 g/l. Built a series of toxicity of heavy metal salts with respect to the test functions of S. cerevisiae basically coincided. The advantages of the test reaction for suppressing the foaming activity of yeast are technical simplicity, express (a test of response is 15 min), minimal material costs, no need for special microbiological equipment, culture media, maintaining the culture in a viable condition. The proposed reaction can be used as a express bioassay to assess the toxicity of environments contaminated by the pollutants of this class.