Figure 7. Glycine is depleted at stationary phase in SASM.

(a) Glycine level in SASM was monitored by solution NMR using [2-¹³C]glycine-containing SASM. Cultures from designated growth stages were sterile filtered to remove the cells, and ¹H-¹³C HSQC spectra were acquired without arraying F1 dimension. The glycine region of the ¹³C-selected ¹H NMR spectra obtained at different growth stages are shown and the peak integrals were used to quantify the glycine level in the media. (b) The glycine level in the medium is correlated with the culture growth stage.