CEN.PK S. cerevisiae strain overexpressing the HXT 1 gene or the HXT 1 and the Lp LDH gene. Strains were flask-batch grown in minimal (YNB) medium, with glucose as a carbon source. (A) Growth was measured as optical density (OD 660 nm). (B) Residual glucose, g/L. (C) Ethanol produced, g/L. (D) Lactate produced, g/L. The data correspond to the mean values of three independent clones independently tested at least three times. Standard error is lower than 0.03%. Open circles: CEN.PK [LDH]-Control. Closed circles: CEN.PK [HXT 1] [LDH] transformants.