Detroy R W, Cunningham R L, Bothast R J, Bagby M O, Herman A
Northern Regional Research Center, Agricultural Research Science and Education Administration, U. S. Department of Agriculture, Peoria, Illinois 61604.
Biotechnol Bioeng. 1982 May;24(5):1105-13. doi: 10.1002/bit.260240507.
The information presented in this publication represents current research findings on the production of glucose and xylose from straw and subsequent direct fermentation of both sugars to ethanol. Agricultural straw was subjected to thermal or alkali pulping prior to enzymatic saccharification. When wheat straw (WS) was treated at 170 degrees C for 30-60 min at a water-to-solids ratio of 7:1, the yield of cellulosic pulp was 70-82%. A sodium hydroxide extration yielded a 60% cellulosic pulp and a hemicellulosic fraction available for fermentation to ethanol. The cellulosic pulps were subjected to cellulase hydrolysis at 55 degrees C for production of sugars to support a 6-C fermentation. Hemicellulose was recovered from the liquor filtrates by acid/alcohol precipitation followed by acid hydrolysis to xylose for fermentation. Subsequent experiments have involved the fermentation of cellulosic and hemicelluosic hydrolysates to ethanol. Apparently these fermentations were inhibited by substances introduced by thermal and alkali treatment of the straws, because ethanol efficiencies of only 40-60% were achieved. Xylose from hydrolysis of wheat straw pentosans supported an ethanol fermentation by Pachysolen tannophilus strain NRRL 2460. This unusual yeast is capable of producing ethanol from both glucose and xylose. Ethanol yields were not maximal due to deleterious substances in the WS hydrolysates.
本出版物中呈现的信息代表了目前关于从秸秆生产葡萄糖和木糖以及随后将两种糖直接发酵为乙醇的研究结果。在进行酶糖化之前，对农业秸秆进行了热法或碱法蒸煮。当小麦秸秆（WS）在水固比为7:1的条件下于170℃处理30 - 60分钟时，纤维素纸浆的产率为70 - 82%。氢氧化钠提取法得到了60%的纤维素纸浆和可用于发酵生产乙醇的半纤维素部分。将纤维素纸浆在55℃进行纤维素酶水解以生产糖类，用于支持六碳糖发酵。通过酸/醇沉淀从滤液中回收半纤维素，然后进行酸水解得到木糖用于发酵。后续实验涉及纤维素和半纤维素水解产物发酵生产乙醇。显然，这些发酵受到秸秆热法和碱法处理引入的物质的抑制，因为乙醇产率仅达到40 - 60%。从小麦秸秆戊聚糖水解得到的木糖支持了嗜单宁管囊酵母菌株NRRL 2460的乙醇发酵。这种特殊的酵母能够从葡萄糖和木糖两者生产乙醇。由于WS水解产物中存在有害物质，乙醇产量未达到最大值。
