Production of CBH2 enzymes. Percentage of Avicel hydrolysis by yeast culture supernatants grown in (a) YPD medium or (b) in SCD-URA medium (pH 6) for 3 days. The assay incubation time was 24 (grey bars) and 48 (black bars) hours. The values shown are the mean values of three repeats ± standard deviation. Reducing 12% SDS-PAGE of cell free yeast culture supernatants (20 μL) visualized by silver staining. Samples were either deglycosylated with endoH (+) or non-treated (-). The concentration of total secreted protein (mg/L) as determined by the BioRad protein assay is indicated.