Fermentative microorganisms
A variety of microorganisms ranging from fungi and bacteria to
yeast could be utilized to produce ethanol from grass hydrolyzate.
Baker’s yeast, S. cerevisiae, is one of the most popular candidates for
ethanol fermentation. In addition to producing ethanol as its main
fermentation products, S. cerevisiae possesses a high tolerance for
inhibiting compounds compared to other microorganisms
(Almeida et al., 2007). One disadvantage of employing S. cerevisiae
as an ethanol fermenter is its inability to produce ethanol from
sugars beside glucose. Fig. 2a shows the growth of Baker’s yeast
(S. cerevisiae TISTR 5049) in MG hydrolyzate at various overliming
pHs.