EN
Two laboratory experiments were performed to determine the susceptibility of microorganisms to excessive amounts of zinc diffusing into artificial culture media. The effect of zinc on the growth of pure bacterial cultures in liquid media was determined in experiment 1, while the diameters of microbial growth inhibition zones in solid media were measured in experiment 2. Zinc was introduced into the media in the form of ZnCl2 and ZnS04 7H20 at the following doses: in mg Zn2+ dm-3 of medium: 0, 5, 100, 500, 1,000, 1,500, 2,000 (experiment 1), in µg Zn+2 disk-1 : 25, 50, 100, 200, 400, 800, 1,600 (experiment 2). It was found that this metal had a strongly toxic effect on all bacterial species analyzed in liquid media.