Overexpression of HXT 1 or HXT 7 genes in the S. cerevisiae CEN.PK strain. 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. 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-Control. Closed circles: CEN.PK [HXT 1] transformants. Open squares: CEN.PK [HXT 7] transformants.