Inactivation of KhpB (EloR/Jag) in <i>Lactococcus cremoris</i> increases uptake of the compatible solute glycine-betaine and enhances osmoresistance.

ABSTRACT: The second messenger cyclic-di-AMP (c-di-AMP) is a signaling molecule widely present in gram-positive bacteria, where it regulates osmotic resistance by controlling potassium and compatible solute transport. Our previous studies using a Lactococcus cremoris model strain demonstrated that mutants with elevated c-di-AMP can overcome osmosensitivity through mutations enhancing potassium transporter activity. To identify additional mechanisms that enhance osmoresistance, we conducted a salt-resistance suppressor screen in an industrial L. cremoris strain. Using a spontaneous GdpP phosphodiesterase mutant with high c-di-AMP, we isolated salt-resistant suppressor mutants harboring six independent mutations in the khpB gene. These khpB mutants maintained elevated c-di-

SUBMITTER: Xiang Y 

PROVIDER: S-EPMC12542702 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature