The effect of EDTA on Salmonella enterica serovar Typhimurium was studied in different growth phases with cells grown with or without Ca2+ and Mg2+ supplementation. EDTA affected the outer membrane much more strongly in the early exponential phase than in the mid- or late exponential phase, as indicated by uptake of 1-N-phenylnaphthylamine (a nonpolar hydrophobic probe, M r 219), and detergent (SDS) susceptibility. This effect was, however, not paralleled by LPS release (determined by measuring LPS-specific fatty acids or 14C-labelled LPS in cell-free supernatants, per a standardized cell density), which remained unchanged as a function of the growth curve. The conclusion from these results is that in the early exponential phase the effect of EDTA in S. enterica involves a component that is independent of LPS release.
Alakomi, H-L., Saarela, M., & Helander, I. (2003). Effect of EDTA on Salmonella enterica serovar Typhimurium involves a component not assignable to lipopolysaccharide release. Microbiology, 149(8), 2015-2021. https://doi.org/10.1099/mic.0.26312-0