O203 高速度発酵細菌によるセルロース系バイオマスからのエコエタノール製造

抄録

Because of the need for development of alternative sources of liquid fuels, ethanol production from renewable resources has become important. Although yeast are used commercially in the traditional methods for ethanol production, Zymomonas mobilis and Zymobacter palmae are now being studied because of their potential for being used in fuel ethanol production. Zm. mobilis and Zb. palame are facultative anaerobic, gram-negative bacteria, and produce about 1.9 mol of ethanol from 1 mol of glucose, similar to industrial yeasts. As the advantages of these bacteria are their high growth rate and specific ethanol production, we focused on the production of fuel ethanol from cellulosic wastes by these bacteria. We therefore developed the unique host-vector systems for Zm. mobilis and Zb. palmae, respectively, and used the systems to expand the range of carbohydrate substrates utilized by these bacteria to include xylose, mannose, and cellooligosaccharides, which are hydrolysis products from cellulosic materials with an enzymatic-or acidic treatment. The recombinant strains exhibited efficient expression of genes encoding fermentation abilities of components of cellulose and hemicellulose, and produced ethanol from xylose, mannose, and cellooligosaccharides with a theoretical yield.