The molasses was supplied by a soybean processing company (IMCOPA) located in the Southern Region of
Brazil, in the concentrated form (600 g L-1 of soluble solids),
and was stored at room temperature, during no more than 3
months. This material is rich in fermentable sugars (fructose,
glucose and mainly sucrose, as far as stachyose and raffinose)
as shown in Table 1. Besides, it has considerable amounts of
proteins, fibers, ash and inorganic salts.
Soybean molasses is produced during soy protein
concentrate production, as shown in Fig. 1:
The objective of this work was to evaluate the best levels of
some important variables for fermentation (concentration of
soybean molasses, pH and time of aerobial phase). Another
goal is to show the profile of consumption of sugars during the
fermentation as well as the profiles of ethanol production in
a bench scale batch reactor. Finally, to make a comparison
between the performance of Zymomonas mobilis and
Saccharomyces cerevisiae in respect of ethanol production,
productivity and yields