In an attempt to define the optimal time for the simultaneous
hydrolysis and fermentation of SM, we determined the kinetic profiles
of substrate consumption, ethanol production and cell growth.
Fig. 5 depicts the behavior of sugars, ethanol and cell growth with
respect to the length of simultaneous hydrolysis and fermentation.
From Fig. 5, we concluded that the optimal time for the fermentation
and simultaneous enzymatic hydrolysis of soybean molasses
was no longer than 12 h. After 12 h larger proportion of sugars
was consumed, and there was no further production of ethanol
by this time. Therefore, the total time to produce ethanol with
simultaneous hydrolysis and fermentation was 12 h, which was
shorter than the total processing time for fermentation following
enzymatic hydrolysis (14 h). To improve ethanol production
under these conditions, a CCD was proposed that analyzed the