Exploration of separate hydrolysis and fermentation and simultaneous saccharification and co-fermentation for acetone, butanol, and ethanol production from combined diluted acid with laccase pretreated Puerariae Slag in Clostridium beijerinckii ART44

Abstract

In this study, an efficient pretreatment technology was developed for the bioconversion of puerariae slag (PS) into biobutanol. To accelerate the enzymatic saccharification of PS, the method of dilute acid combined with laccase pretreatment (DALP) was performed. With this effort, the highest concentration of reducing sugar was 48.96 ± 1.69 g/L after enzymatic hydrolysis of the whole slurry pretreatment under the optimal condition. Subsequently, the highest butanol productivity (0.15 g/L/h) was obtained by the simultaneous saccharification and co-fermentation (SSCF), which was 114.29% higher than that of the separate hydrolysis and fermentation (SHF). Furthermore, the microstructural changes of PS after different pretreatment were initially investigated by FT-IR, and we found that the DALP method resulted in more severe damage during the pretreatment process, which could improve the efficiency of enzymatic saccharification. This study suggests that the DALP is an attainable and efficient pretreatment method for production of butanol in the SSCF process.