[The homeostasis of the microbial communities in soils polluted by heavy metals]

Homeostatic potentialities of microbial communities in soils contaminated with heavy metals have been studied. To estimate the effect of contaminants on the soil microflora it was proposed to use the indices characterizing homeostasis of microbial community: microorganism survivability in contaminated soil and the period of restoration of their number, sensitivity to certain contaminants. In the model experiments on dark-grey podzolized soil it was shown that contamination with heavy metals (Cu2+, Cd2+, Sr2+, Pb2+, Hg2+) in the doses of 2 and 4 maximum permissible concentrations provokes a short-term inhibition of microorganisms development after which their number restores. Introduction of the mixture of metals evokes more intensive inhibition and extends the period of microorganism number restoration as compared with the effect of certain metals in the same doses.