A Steam-Explosion-Based Hydrolysis and Acidification Technology for Cornstalk Bioconversion

Acidification is a potential solution to lignocellulose conversion. In this work, steam explosion was proposed to pretreat cornstalk and improve acidification bioconversion efficiency. Results showed that steam explosion improved the conversion ratio by 17% compared with the control group. The optimum temperature of the hydrolysis and acidification system was 50 degrees C and the microbial community showed higher hydrolysis and acidification efficiency at pH 8.0-9.0, which were 66.0% (pH 8.0) and 68.0% (pH 9.0), respectively. An organic nitrogen source was more preferred by the microbial community than an inorganic nitrogen source. The highest conversion ratio (67.0%) was observed when the yeast extract dose was 1.0 g/L. Steam-exploded cornstalk was degraded by the microbial community, and organic acids in hydrolysis and acidification liquid was effectively reused by R. eutropha H16 (The utilization ratios of acetic acid, propionic acid and butyric acid were 53.38, 12.27 and 20.95%, respectively.). Based on this study, steam-explosion-based conversion technology is proposed and has great potential in future application of lignocellulose conversion.