After fermentation of sugars to ethanol using the different
microorganisms (Z. mobilis and S. cerevisiae) separately, a coculture
fermentation was done using a broth containing
xylose and glucose sugars (see Fig. 3).
Acombinationof thetwomicroorganismsinthesame sugar
mixture was also investigated in this study. It was found that S.
cerevisiae and Z. mobilis worked better when they were used in
the same broth, since an even higher ethanol concentration of
9.3 g/L was obtained. Glucose was thoroughly fermented to
ethanol while the xylose yield was very low after 48 h. The increase
in ethanol concentration is due to high competition of S.
cerevisiae and Z. mobilis for thesamesource of substrate, this led
to a very rapid conversion of sugars to ethanol.