Enzymatic saccharification of pretreated sunflower stalks

The sunflower stalks were pretreated by steam explosion (at 1.05 kg/cm2 for 0.5–1.5 h) and sodium hydroxide (0.25–1.5% w/v NaOH at 1.05 kg/cm2 for 0.5–1.5 h) using solid:liquid ratio of 0.05 g/ml and subsequently saccharified enzymatically. Steam explosion at 1.05 kg/cm2 pressure for 1.5 h was found to be the optimum pretreatment. Maximum enzymatic saccharification of 57.8% was observed by treating 5% (w/v) pretreated sunflower stalks with T. reesei Rut-C 30 cellulase (25 FPU/g) at 50°C, pH 5.0 for 72 h.