Figure 5 . Time course of D-tagatose production from 100 g/L lactose and 122 g/L cheese whey powder (including 100 g/L lactose) (A). Fermentation of mixed sugar syrup derived from lactose and cheese whey powder by S. cerevisiae (B). Solid dots represent lactose as substrate, and hollow dots represent whey powder as substrate. Experiments were performed in triplicates, and error bars represent the standard deviation.