Efficient high solid loading enzymatic hydrolysis of hydrogen peroxide/acetic acid-pretreated bamboo for monosaccharides production

High solid loading enzymatic hydrolysis (HSLEH) produces high sugar concentrations with low water and energy inputs. Adequate information has been provided to confirm the excellent enzymatic digestibility of pretreated bamboo biomass with the solid content below 10%. However, the utilization of bamboo biomass for producing high-concentration sugars solution via HSLEH is rarely reported. In this work, hydrogen peroxide/acetic acid (HPAC) pretreatment removed 79% of lignin from bamboo and HPAC-pretreated bamboo was rich in glucan (55.3%) and xylan (20.4%). In the HSLEH of HPAC-pretreated bamboo, xylanase could increase glucose production by 9.4%. Alkaline incubation could increase the glucose production of HPAC-pretreated bamboo by 6.3% and saved 75% cellulase. The addition of Tween 80 (0.03 g/L) could further increase the glucose production of HPAC-pretreated bamboo by 14.1%. As a result, 204.9 g/L glucose and 60.2 g/L xylose, corresponding to glucose and xylose yields of 75.8% and 65.4% respectively, were obtained from the resulting bamboo solid via 400 g/L HSLEH with 10 FPU cellulase/g dry matter and 0.03 g/L Tween 80, which was the highest concentration compared with the previous literatures. This work developed an integrated process to produce very high-concentration sugars solution from bamboo residue via HSLEH.