A time course was performed to further characterize the effect
of glucose on growth, prodigiosin production, and the pH of the
culture medium under our experimental conditions (Fig. 1). Exogenous
glucose did not inhibit the initial rate of growth but was
associated with a more rapid achievement of stationary phase and
a lower final culture density (Fig. 1A). As expected, prodigiosin
production occurred in stationary phase in LB medium and was
not detected in glucose-rich medium (Fig. 1B). Culture pH increased
over time in LB medium but became highly acidified in
LBG, with the maximal change occurring between 3 and 6 h
(Fig. 1C).