Digestibility or saccharification of cotton, jeans or Avicel as a reference were investigate by enzymatic hydrolyses at 45 °C and pH 4.8 (with 50 mM sodium citrate buffer) with 3% w/v solid substrates, using 20 FPU cellulase and 30 IU b-glucosidase per gram cellulose within 24–96 h. The hydrolyzate or glucose solution were then supplemented with other nutrients (Karimi et al., 2006), inoculated with 10 ± 3 g/L S. cerevisiae, and cultivated at 37 °C for 4 days. The yields for pretreated materials were calculated based on the amount of retrieved cellulose after pretreatment. All experiments were performed at least in duplicate and results are presented as average values. The average standard deviation of the results was 4.0%