Enzymatic hydrolysis and simultaneous saccharification and fermentation of alkali/peracetic acid-pretreated sugarcane bagasse for ethanol and 2,3-butanediol production

• Published in: Enzyme and microbial technology 2011-09, Vol.49 (4), p.413-419
• Main Authors: Zhao, Xuebing, Song, Yuanquan, Liu, Dehua
• Format: Article
• Language: English
• Subjects: Alkalies - pharmacology; beta-glucosidase; Biological and medical sciences; Biotechnology; Biotechnology - methods; Butylene Glycols - metabolism; Cellobiose - metabolism; Cellulase - metabolism; Cellulose - metabolism; Cellulose - pharmacology; Culture Media; Delignification; endo-1,4-beta-glucanase; Enzymatic hydrolysis; ethanol; Ethanol - metabolism; Fermentation; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Hydrolysis; Klebsiella pneumoniae; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; peracetic acid; Peracetic Acid - pharmacology; Pretreatment; pulp; saccharification; Saccharum - drug effects; Saccharum - metabolism; Simultaneous saccharification and fermentation; Sugarcane bagasse; syrups; xylose; Xylose - metabolism
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2011.07.003

The enzymatic digestibility of alkali/peracetic acid (PAA)-pretreated bagasse was systematically investigated. The effects of initial solid consistency, cellulase loading and addition of supplemental β-glucosidase on the enzymatic conversion of glycan were studied. It was found the alkali–PAA pulp showed excellent enzymatic digestibility. The enzymatic glycan conversion could reach about 80% after 24 h incubation when enzyme loading was 10 FPU/g solid. Simultaneous saccharification and fermentation (SSF) results indicated that the pulp could be well converted to ethanol. Compared with dilute acid pretreated bagasse (DAPB), alkali–PAA pulp could obtain much higher ethanol and xylose concentrations. The fermentation broth still showed some cellulase activity so that the fed pulp could be further converted to sugars and ethanol. After the second batch SSF, the fermentation broth of alkali–PAA pulp still kept about 50% of initial cellulase activity. However, only 21% of initial cellulase activity was kept in the fermentation broth of DAPB. The xylose syrup obtained in SSF of alkali–PAA pulp could be well converted to 2,3-butanediol by Klebsiella pneumoniae CGMCC 1.9131.