Fig. 3

Ethanol production profile of S. cerevisiae strain T₂ fermentation of whole slurry hydrolysate after one-stage acid bisulphite or SO₂-catalyzed steam pretreatment of lodgepole pine. The one-stage sulphite steam pretreatment was performed by using 8% NaHSO₃ and 2% H₂SO₄ at 210 °C for 10 min. Enzymatic hydrolysis of the sulphite steam-pretreated substrates was conducted at a solids loading of 25% for 48 h with a cellulase loading of 40 mg protein per g cellulose. The yeast concentrations (cell optical density: OD) were 6.5