Glycine Betaine Transport in Lactococcus lactis Is Osmotically Regulated at the Level of Expression and Translocation Activity

Microorganisms react upon hyperosmotic stress by accumulating compatible solutes. Here we report that Lactococcus lactis uses a transport system for glycine betaine that, contrary to earlier observations (D. Molenaar et al., J. Bacteriol. 175:5438–5444, 1993), is osmotically regulated at the levels of both expression and transport activity.