Abstract
The effects of ethylenediaminetetraacetic acid (EDTA) and its salts, alone or in combination with Mg2+, Fe3+, Zn2+ or Ca2+, on growth of S. aureus strain 196E, were studied. EDTA or its Na+ or K+ salts (0.8–1.7 mM), but not its Ca2+ or Fe3+ salts, inhibited cell growth in Brain Heart Infusion broth. Bacteriostatic effects in Casamino Acids‐Yeast Extract (CasY) broth were produced by 0.17 mM EDTA. Addition of Fe3+, Zn2+, or Ca2+ to EDTA‐containing broth eliminated inhibition at an EDTA: cation molar ratio of 1:1, while Mg2+ required a sevenfold concentration. Data suggest that EDTA exerts its inhibitory effect by chelating calcium and/or other essential cations which form complexes with comparable stability constants with EDTA.
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