Hydrolysis of pretreated rice straw with surfactants at low cellulase dosage

he effects of three surfactants (Tween 80, saponin and monorhamnolipid) on the hydrolysis of NaOH-pretreated rice straw by low dosage of cellulase were studied. The results indicated that with a relatively low cellulase dosage (4 FPU g-1 substrate), all surfactants were able to enhance the enzymatic hydrolysis, while the biosurfactant monorhamnolipid was demonstrated to be more active than Tween 80 and saponin. Monorhamnolipid at 0.006% increased reducing sugar yield by 23.15%, and the maximal sugar yield was obtained within half of the time compare to the control required. The cellulase losed 67% of its activity in the control, while the activity lost ratios were 31%~43% in the presence of the surfactants. The surfactants addition did not affect the pH of the hydrolysis system. This study provides an opportunity of decreasing enzyme dosage in hydrolysis of agricultural solid waste rich in cellulose.