higher cell number of A. oryzae on the gel beads surface causing
a restriction of residual sugar in the inner part of the cell beads and
therefore reducing ethanol production. As a result of this most
sugars were used for cell growth and maintenance rather than
ethanol production. In order to improve the ethanol fermentation
yields, mixed cultures of A. oryzae and M. purpureus at a ratio of 1:1,
2:1 and 3:1 were used. Fig. 8a showed the residual starch to be 0.13,
0.13 and 0.15% (w v1
) for the ratio 1:1, 2:1 and 3:1, respectively.