Enhancement of converting corn stalk into reducing sugar by ultrasonic-assisted ammonium bicarbonate pretreatment

In order to improve the yield of reducing sugar from corn stalk, ultrasonic-assisted ammonium bicarbonate pretreatment of corn stalk was proposed. Three ultrasonic factors (time (0-30 min), temperature (30-60 degrees C) and liquid/solid mass ratio (5-20)) were optimized by response surface experiment. The optimal conditions of ultrasonic pretreatment were obtained (liquid/solid mass ratio is 12:1, temperature is 42 degrees C and time is 11 min). The highest saccharification rate of corn stalk was of 82.61%, which was remarkably increased by 355% compared to the control group.