Fig. 2

Saccharification yields of batch OS-pretreated birch and spruce biomass at 2% solids loading using 20 mg of the enzyme preparation/g_solids; a, b Birch [without and with 1% H₂SO₄ catalyst pretreated with 50 or 60% ethanol at 60 or 103 min for a particle size of < 1 or < 4 mm;]. c, d Spruce [without and with 1% H₂SO₄ catalyst pretreated with 50 or 60% ethanol at 60 or 103 min for a particle size of < 1 or < 4 mm;]. See Table 1 for details of the pretreatment conditions. The results shown are the average of two experiments. Columns with dots indicate OS with acid catalyst