Bioconversion of renewable lignocellulosic biomass into multicomponent substrate via pressurized hot water pretreatment for bioplastic polyhydroxyalkanoate accumulation

Abstract

The pretreatment of lignocellulosic biomass (LB) has become an important process to reduce the cost of polyhydroxyalkanoate (PHA) production. In this study, an economical and effective pressurized hot water pretreatment was used to investigate on bioconversion of four typical LB (rubber wood, sugarcane bagasse, sorghum stalk, cassava stalk) into reducing sugar, then as feedstock to accumulate PHA by mixed microbial cultures. The results showed that pretreatment changed the surface morphology of LB and further improved saccharification efficiency. The maximum reducing sugar yield of 620.7 mg·g−1 (438.7 mg·g−1 glucose and 178.0 mg·g−1 xylose) was obtained by rubber wood. The conversion of cellulose and hemicellulose reached 83.10% and 78.22%. Moreover, PHA content reached the maximum of 773.2 mg COD·L−1 in the operation cycle of 24 h. The results demonstrated that hot water pretreatment was an effective physical process to improve the saccharification efficiency of LB for reducing the cost of PHA.