Simultaneous saccharification and co-fermentation of dry diluted acid pretreated corn stover at high dry matter loading: Overcoming the inhibitors by non-tolerant yeast

• Published in: Bioresource technology Vol. 198; pp. 39 - 46
• Main Authors: Zhu, Jia-Qing, Qin, Lei, Li, Wen-Chao, Zhang, Jian, Bao, Jie, Huang, Yao-Dong, Li, Bing-Zhi, Yuan, Ying-Jin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2015
• Subjects: Acids - pharmacology; Biomass; Bioreactors; Desiccation; Ethanol - pharmacology; Fed-batch fermentation; Fermentation; High solid loading; Inhibitor tolerance; Lignin; Saccharomyces cerevisiae - drug effects; Simultaneous saccharification and co-fermentation; Solvents - pharmacology; Time Factors; Xylose - pharmacology; Xylose utilization; Zea mays - drug effects; Simultaneous saccharification and co-fermentation; Xylose utilization; High solid loading; Inhibitor tolerance; Fed-batch fermentation
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2015.08.140

•Efficient conversion of pretreated corn stover at high solid loading was achieved.•Ethanol titer reached 47.2g/L at 25% dry matter loading of pretreated corn stover.•Inhibitors significantly reduced xylose utilization at high dry matter loading.•The toxicity of inhibitors to yeast increased at high temperature. Dry dilute acid pretreatment (DDAP) is a promising method for lignocellulose bioconversion, although inhibitors generated during the pretreatment impede the fermentation severely. We developed the simultaneous saccharification and co-fermentation (SScF) of DDAP pretreated biomass at high solid loading using xylose fermenting Saccharomyces cerevisiae, SyBE005. Effect of temperature on SScF showed that ethanol yield at 34°C was 10.2% higher than that at 38°C. Ethanol concentration reached 29.5g/L at 15% (w/w) dry matter loading, while SScF almost ceased at the beginning at 25% (w/w) dry matter loading of DDAP pretreated corn stover. According to the effect of the diluted hydrolysate on the fermentation of strain SyBE005, a fed-batch mode was developed for the SScF of DDAP pretreated corn stover with 25% dry matter loading without detoxification, and 40.0g/L ethanol was achieved. In addition, high yeast inoculation improved xylose utilization and the final ethanol concentration reached 47.2g/L.