Fig. 4

The batch-feeding whole-cell catalysis processes catalyzed by different cell density in a laboratory scale. The 50 mL reaction mixture contained 1.2 M sucrose, 60 mM initial concentration of hydroquinone, 50 mM PBS (pH 7.0), and different cell density including a 20.0 of OD₆₀₀ (1.6 U/mL); b 10.0 of OD₆₀₀ (0.8 U/mL); c 5.0 of OD₆₀₀ (0.4 U/mL); d 1.0 of OD₆₀₀ (0.08 U/mL). The reactions were performed in 100 mL round-bottom flask incubated in a thermostatic waterbaths with a magnetic stirrer at 30 °C. Hydroquinone was constantly added into reaction mixture. Sucrose was also supplemented at 9 h in the reaction (a, b). Square: α-arbutin, circle: sucrose, up triangle: glucose, down triangle: fructose