Ethanol can be produced from cellulosic biomass in a process known as simultaneous saccharification
and fermentation (SSF). The presence of yeast together with the cellulolytic enzyme complex reduces
the accumulation of sugars within the reactor, increasing the ethanol yield and saccharification rate. This
paper reports the isolation of Saccharomyces cerevisiae LBM-1, a strain capable of growth at 42 C. In addtion, S. cerevisiae LBM-1 and Kluyveromyces marxianus UFV-3 were able to ferment sugar cane bagasse in
SSF processes at 37 and 42 C. Higher ethanol yields were observed when fermentation was initiated after
presaccharification at 50 C than at 37 or 42 C. Furthermore, the volumetric productivity of fermentation
increased with presaccharification time, from 0.43 g/L/h at 0 h to 1.79 g/L/h after 72 h of presaccharification. The results suggest that the use of thermotolerant yeasts and a presaccharification stage are key to
increasing yields in this process.