Fig. 3

Productivities of cycling fermentation experiments. Ethanol volumetric productivity (a), specific productivity (b), and overall productivity (c) were determined for manual cycling experiments. The horizontal solid line represents the mean values obtained through a dynamic batch study (Fig. 1), where ethanol production reached a plateau at ~20.5 h. Error bars represent standard deviation of triplicate experiments, except for cycle 4 in b, which represents duplicate samples (see “Methods”). Means that do not share the same letter are statistically different (95% confidence level, Tukey)