2.2. Culture conditions
A colony of yeast cells was pre-cultured in 5 mL YPD for 24 h at 30°C and 250 rpm. The culture containing 25 or 2.5 mg cells was centrifuged at 15,000 rpm for 1 min at 4°C. The cells were resuspended in 50 mL YPD (40 g/L glucose) or YPX (40 g/L xylose) in a 250 mL Erlenmeyer flask, and the culture with an initial cell density of 0.5 or 0.05 g/L was incubated at 30°C and 80 rpm. All experiments were done in triplicated.