Effect of Heavy Metals on the Abundance of Bacteria of the Genus Аzotobacter in Gray-Brown Soils of the Аbsheron Peninsula

The effect of different concentrations of heavy metals in gray-brown soils of the Absheron Peninsula on the abundance of bacteria of the genus Azotobacter has been studied. The indicators of the total number of microorganisms and the abundance of bacteria of the genus Azotobacter were taken as informative indicators. It is shown that in the studied soil, with an increase in the concentration of heavy metals (TM) at all accounting periods, a decrease in the total number of microorganisms was observed compared with the control. The study of the abundance of bacteria g. Azotobacter of gray-brown soil showed that bacteria of this genus had sufficient resistance to the effects of TM. At concentrations of 1 MPC, no definite effect of heavy metals on bacteria of this genus was detected. However, with the action of TM at concentrations of 5 and 10 MPC, a decrease in the abundance of bacteria was observed in relation to the control. The studied metals according to their inhibitory effect, depending on the nature of pollutants, can be arranged in a row: Cr > Pb > Cu.