Fig 2.

β-glucosidase production of S. cerevisiae cultures grown in raffinose-YPD medium after galactose induction. An aliquot of an overnight culture grown in DOB medium was used to inoculate raffinose-YPD medium. After growth to an OD₆₀₀ of 1.0, sterile galactose was added. Samples were withdrawn at the time points shown. The OD₆₀₀ of control culture (●), OD₆₀₀ (○), and β-glucosidase activity of cell extract (□) and culture medium (■) of transformant no. 7 were determined. Culture conditions, preparation of the samples, and enzyme assays were described in Materials and Methods. The control culture corresponded to the yeast containing the pYES2 without any insert.