Biochemical Engineering Department, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21945-970, Brazil.
Appl Biochem Biotechnol. 2011 Apr;163(7):928-36. doi: 10.1007/s12010-010-9096-8. Epub 2010 Oct 3.
Current research indicates the ethanol fuel production from lignocellulosic materials, such as residual wood chips from the cellulose industry, as new emerging technology. This work aimed at evaluating the ethanol production from hemicellulose of eucalyptus chips by diluted acid pretreatment and the subsequent fermentation of the generated hydrolysate by a flocculating strain of Pichia stipitis. The remaining solid fraction generated after pretreatment was subjected to enzymatic hydrolysis, which was carried out simultaneously with glucose fermentation [saccharification and fermentation (SSF) process] using a strain of Saccharomyces cerevisiae. The acid pretreatment was evaluated using a central composite design for sulfuric acid concentration (1.0-4.0 v/v) and solid to liquid ratio (1:2-1:4, grams to milliliter) as independent variables. A maximum xylose concentration of 50 g/L was obtained in the hemicellulosic hydrolysate. The fermentation of hemicellulosic hydrolysate and the SSF process were performed in bioreactors and the final ethanol concentrations of 15.3 g/L and 28.7 g/L were obtained, respectively.
目前的研究表明，从木质纤维素材料（如纤维素工业的剩余木屑）中生产乙醇燃料是一种新兴技术。本工作旨在评估用稀酸预处理桉树屑中的半纤维素，并随后用絮凝酿酒酵母（Pichia stipitis）菌株发酵生成的水解产物来生产乙醇。预处理后产生的剩余固体部分进行酶水解，同时使用酿酒酵母（Saccharomyces cerevisiae）菌株进行葡萄糖发酵[糖化和发酵（SSF）过程]。采用中心复合设计对硫酸浓度（1.0-4.0 v/v）和固液比（1:2-1:4，克/毫升）作为自变量进行酸预处理评估。在半纤维素水解产物中获得了 50 g/L 的最大木糖浓度。在生物反应器中进行半纤维素水解物的发酵和 SSF 过程，分别获得了 15.3 g/L 和 28.7 g/L 的最终乙醇浓度。
