Fermentation of the Straw Material Paja Brava by the Yeast <i>Pichia stipitis</i>in a Simultaneous Saccharification and Fermentation Process

• 作者: Christian Roslander Cristhian Carrasco Gunnar Lidén Henrique Baudel Mats Galbe
• 来源期刊: 可持续生物质能源系统(英文)
• 学科: 医学
• 关键词: Ethanol LIGNOCELLULOSE FERMENTATION XYLOSE
• 年，卷（期）: 2013,（2）
• 页码范围: 99-106
• 页数: 8页
• 分类号: R73

摘要

Paja Brava is a native South American grass with a high carbohydrate content. In the current work, the potential of using this feedstock for ethanol production using a simultaneous saccharification and fermentation (SSF) process with the xylose-fermenting yeast Pichia stipitis (Scheffersomyces stipitis) CBS6054 was investigated. The straw material was subjected to SO2 catalyzed steam pretreatment at 200°C and 5 min residence time, which resulted in a solubilization of pentose sugars (mainly xylose) of 64% with only minor amounts of degradation products. The obtained material, including the pretreatment liquid, was subsequently hydrolyzed and fermented in an SSF process at microaerobic conditions using either a batch or a fed-batch process at a total water-insoluble solids loading of 10%. Overall yields of ethanol based on all available sugars of 0.24 g/g and 0.27 g/g were obtained for batch and fed-batch mode of operation, respectively. The higher yield in the fed-batch process coincided with a higher degree of conversion of the sugars in the liquid medium, in particular of arabinose, for which the conversion was doubled (from 48% to 97%).