Two-step acid and alkaline ethanolysis/alkaline peroxide fractionation of sugarcane bagasse and rice straw for production of polylactic acid precursor

作者：Sakdaronnarong Chularat^*; Srimarut Nattawee; Lucknakhul Nawapol; Na Songkla Norased; Jonglertjunya Woranart

来源：Biochemical Engineering Journal, 2014, 85: 49-62.

DOI：10.1016/j.bej.2014.02.003

• Lignocellulose organosolv fractionation
• Ultrasonication
• Lignocellulose valorization
• Lactic acid production
• Polylactic acid precursor

Sugarcane bagasse and rice straw were subjected to acid and alkaline ethanolysis and sequential enzymatic hydrolysis to produce glucose for lactic acid production. Influence of physico-chemical treatments using ultrasonic bath and ultrasonic probe was studied compared with mechanical stirring. The results showed that the highest glucose yield with least contamination of xylose was obtained from acid ethanolysis fractionation (5 N H2SO4 + 50%, v/v ethanol) when stirred at 90 degrees C for 4 h. Alkaline ethanolysis accomplished high amount of both glucose and xylose released, however it was not favorable substrate for homofermentative lactic acid bacteria. In order to enhance enzymatic hydrolysis of acid ethanolysis fractionated samples, lignin was subsequently removed by the second step alkaline/peroxide deligniflcation. The maximum lactic acid was obtained at 23.6 +/- 0.2 g/L from Lactobacillus casei fermentation after 72 h when hydrolysate from two-step acid hydrolysis and alkaline/peroxide fractionated sugarcane bagasse containing 24.6 g/L initial glucose concentration was used as substrate.

• 出版日期2014-4-15