Divalent Cations (Ca, Mg, Mn, Fe, Ni, and Zn) Enhance Growth of and . by Reducing Generation Time.

Bacterial ion homeostasis is critical for adaptation and survival. In this study, we show that supplementing 2xTY medium with divalent cations (Ca, Mg, Mn, Fe, Ni, and Zn) from 50 to 1,000 μM significantly enhances the growth of species by reducing generation time, while monovalent ions (Na, K, Li, and Cl) had no significant effect. Among them, Ca effectively boosted . fitness, increasing the specific growth rate by up to 223%, shortening the cell cycle, and enhancing adhesion to abiotic surfaces up to 8-fold. Calcium also induced a more uniform and smaller cell morphology, suggesting improved cell division and metabolic efficiency. Colony forming unit counts confirmed a higher viability, excluding dead cell accumulation. These effects were conserved in other Xanthomonadaceae members (. and . ) but not in nonrelated species. Based on these findings, we propose an optimized growth medium named 2xTY-Ca (16 g/L tryptone, 10 g/L yeast extract, 5 g/L NaCl, and 1 mM CaCl), which significantly improves spp. growth kinetics , enhancing . and . cultivation for laboratory and industrial applications. Though the precise molecular mechanism behind these phenotypes has yet to be determined, we highlight . as a promising organism to understand the role of divalent cations in bacterial physiology.