Zinc is an essential cofactor for bacterial metabolism, and many Enterobacteriaceae express the zinc transporters ZnuABC and ZupT to acquire this metal in the host. However, the probiotic bacterium Escherichia coli Nissle 1917 (or “Nissle”) exhibits appreciable growth in zinc-limited media even when these transporters are deleted. Here, we show that Nissle utilizes the siderophore yersiniabactin as a zincophore, enabling Nissle to grow in zinc-limited media, to tolerate calprotectin-mediated zinc sequestration, and to thrive in the inflamed gut. We also show that yersiniabactin’s affinity for iron or zinc changes in a pH-dependent manner, with increased relative zinc binding as the pH increases. Thus, our results indicate that siderophore metal affinity can be influenced by the local environment and reveal a mechanism of zinc acquisition available to commensal and pathogenic Enterobacteriaceae.

锌是细菌代谢的必需辅助因子，许多肠杆菌科表达锌转运蛋白 ZnuABC 和 ZupT 以在宿主中获取这种金属。然而，益生菌大肠杆菌Nissle 1917（或“Nissle”）在锌限制培养基中表现出明显的生长，即使这些转运蛋白被删除。在这里，我们表明 Nissle 利用铁载体耶尔森菌素作为锌载体，使 Nissle 能够在锌限制的培养基中生长，耐受钙卫蛋白介导的锌螯合，并在发炎的肠道中茁壮成长。我们还表明，耶尔森菌素对铁或锌的亲和力以 pH 依赖性方式变化，随着 pH 值的增加，相对锌结合增加。因此，我们的结果表明，铁载体金属亲和力会受到当地环境的影响，并揭示了一种可用于共生和致病性肠杆菌科的锌获取机制。