EN
In this paper the effect of Mo6+, W6+, and Cu2+ ions on kinetics of denitrification and growth of Bacillus licheniformis is presented. The absence lack of Mo6+ and Cu2+ in the growth medium appeared to have no effect on the kinetics of the process. This fact suggests that these ions are not a part of the active centers of denitrification enzymes. Additionaly tungsten (VI) which is competitive to molybdenum (VI) does not inhibit denitrification in concentrations up to 0.1 g/dm3. Molibdenum (VI) starts to inhibit denitrification from 5.0 g/dm3 and copper (II) starting from 0.03 g/dm3.