USDA Forest Service, Forest Products Laboratory, Madison, WI, USA.
Appl Microbiol Biotechnol. 2010 May;86(5):1355-65. doi: 10.1007/s00253-009-2408-7. Epub 2010 Jan 14.
Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quais-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 degrees C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance.
从森林采伐剩余物中提取的花旗松是生产乙醇的潜在原料。在这项研究中，花旗松被转化为乙醇，每公吨木材的得率为 276 升，或理论得率的 72%。花旗松木屑直接进行亚硫酸盐预处理以克服木质纤维素的顽固性（SPORL）预处理，然后用圆盘磨碎；回收的纤维素基质用商业纤维素酶和酿酒酵母 D5A 进行准同时酶解糖化和发酵成乙醇。预处理后的含水解糖的蒸煮液（主要来自半纤维素）在使用 XAD 树脂柱进行解毒后，由相同的酵母菌株发酵。SPORL 预处理在实验室消化器中于 180°C 进行 25 分钟，液比为 3:1（v/w）。施加了三个硫酸用量（基于风干木材的 0.0%、1.4%和 2.2%（w/w））和三个亚硫酸氢钠用量（基于风干木材的 0.0%、4.0%和 8.0%（w/w））。测定了粉碎和预处理的机械能和热能消耗。这些数据用于确定糖回收效率和净乙醇能量产生值，并制定初步的质量和能量平衡。
