In the present invention, there is described a targeted modification method of a yeast strain enabling the detection of heavy metals or other harmful substances in environment, optionally other substances that are significant from industrial, medicinal and biotechnological point of view. This system employs yeast inducible promoters and breakage of AMP biosynthetic path through deletion of ADE2 or ADE1 gene, which causes, in the presence of a concrete harmful substance, reddening of the yeast culture.
The invention also discloses a detection method that is very simple, quick and undemanding as far as instrumentation is concerned. The detection yeast strain that is immobilized in alginate balls, is first statically incubated over night in the presence of a sample to be tested.
Subsequently, the balls are exposed to the action of oxygen and in the course of several minutes it is possible to determine, whether a tested substance is present in the sample and optionally the approximate amount thereof.