Antibacterial testing of metal ions using a chemically defined medium

Data from in-vitro tests on potential germicides can be greatly influenced by the culture medium. The bioavailability and biochemical reactivity of the biocides can be influenced by chemical interference with media components (Spooner & Sykes 1972). Bird et al . (1985) showed that metal ions are particularly prone to chemical interferences. A chemically defined solid medium has been developed to monitor the antibacterial activity of metal ions. The minimum inhibitory concentrations of zinc and silver have been determined against a range of bacteria using this medium.