Acid tolerance mediated by membrane ATPases in Lactobacillus acidophilus

Abstract

The acid tolerance response in Lactobacillus acidophilus CRL 639, induced at pH 4.2 for 15 min, is mediated by the cell membrane F1-F0 ATPase. The specific activity of the enzyme was induced 1.6-fold after acid adaptation compared to a non-adapted control. The ATPase was optimal at pH 6 with a Km = 0.8 mM and a Vmax = 100 mM.