FIG. 2.

Compatible solute accumulation by L. monocytogenes 10403S and mutant L. monocytogenes ASA4, ASA5, ASA6, and ASA7 during exponential growth in modified Pine's medium at 7°C with 0.5 mM glycine betaine and carnitine. Exponentially growing cultures were harvested and washed, and cytoplasmic contents were extracted with perchloric acid. Alanine (50 mM) was added to each extract as an internal standard, and compatible solutes were quantitated by using natural-abundance ¹³C-NMR spectroscopy. Error bars indicate ranges of duplicate measurements.