The exposition of a calcareous Mediterranean soil to toxic concentrations of Cr, Cd and Pb produces changes in the microbiota mainly related to differential metal bioavailability

► We assessed microbial composition and activity of an artificially polluted soil. ► Pollutants considered were Cr, Cd and Pb at different concentrations along 28 d. ► Bioavailability is the main factor controlling the effect of the pollutants. ► Native bacteria from this agricultural soil are able to survive pollutants. ► Several multiresistant species are able to reduce Cr(VI) concentration.