Fig. 5
Time-course of fermentation profiles of the parental strain (JHL80, a through c) and redox optimized strain (GAL_083, d through f) in mixtures of galactose and glucose supplemented medium for 48 h. The pH was adjusted to around 7.2 at 6-h intervals. The ratio of galactose to glucose was varied from 2:1 (a, d), to 1:1 (b, e), to 1:2 (c, f). The GAL_083 strain showed the ability to utilize galactose and glucose simultaneously. The left y-offset and right y-axis represent sugar and metabolite (n-butanol, ethanol, and butyrate) concentrations (g/L), respectively. The left y-axis represents OD600. The x-axis represents time in culture (h). The error bars indicate standard deviations of measurements from two independent cultures. Symbols: open circle OD600; open rectangle galactose; closed rectangle glucose; closed up triangle n-butanol; closed diamond ethanol; closed down triangle butyrate