Fig. 4.

Growth inhibition zones of Staphylococcus aureus 124 (A) and Pseudomonas aeruginosa 18 (B) when tested on paper discs after applying copper sulfate solution (ionic form) at different concentrations to the disc: 7; 15 and 20 g/l (shown on an additional scale) respectively they are shown on the ordinate axis as variants 1, variants 2 - zones of growth retardation in case of application to discs of homogenates of D.v-Cu.S cells characterised by low copper content in chelate form, variants 3 - zones of growth retardation after application of homogenates of D.v-Cu. cells. S with the additional, preliminary introduction of sulfuric acid copper in cell homogenates respectively 7; 15 and 20 g/l of sulfuric acid copper, variant 4 - zones of growth retardation after application on discs of homogenates of cells D.v-Cu. R cells (which initially contained a relatively large amount of copper in the chelate form) and variant 5 - growth retardation zones after application of D.v-Cu.R cells homogenates on discs with additional preliminary introduction of 7; 15, and 20 g/l of copper sulfate into homogenates, respectively. The average values from three experiments and their standard errors are presented. ∗ - differences between options 2–3 and 4–5 are significant with P < 0.05.