Properties of ethanol fermentation by Flammulina velutipes.

Basidiomycetes have the ability to degrade lignocellulosic biomass, and some basidiomycetes produce alcohol dehydrogenase. These characteristics may be useful in the direct production of ethanol from lignocellulose. Ethanol fermentation by basidiomycetes was investigated to examine the possibility of ethanol production by consolidated bioprocessing (CBP) using Flammulina velutipes. F. velutipes converted D-glucose to ethanol with a high efficiency (a theoretical ethanol recovery rate of 88%), but ethanol production from pentose was not observed. These properties of F. velutipes are similar to those of Saccharomyces cerevisiae, but the basidiomycete converted not only sucrose, but also maltose, cellobiose, cellotriose, and cellotetraose to ethanol, with almost the same efficiency as that for D-glucose. From these results, we concluded that F. velutipes possesses advantageous characteristics for use in CBP.