2.1. Strains
The microorganism used at this study was Zymomonas
mobilis NRRL 806. The cells were inoculated in ZM medium:
sucrose (20 g L-1), yeast extract, (10 g L-1) and peptone, (10 g L-1);
the growth was performed at shaker (12.6 rad s-1) for 21 h at
30 C, and stored for no more than 3 weeks in refrigerator
(4 C).
The yeast used at the reactor tests was a strain of
Saccharomyces cerevisiae from Biotechnological Processes
Laboratory e UFPR, named S. cerevisiae LPB1.
2.2. Adaptation of the strain
Progressive adaptation of Zymomonas mobilis in soybean
molasses was done through successive transferences from
the seed culture (10% inoculation rate). Initially, it was used
soybean molasses at 50 g L-1 of soluble solids (first transference),
and thereafter (second and third transferences)
soybean molasses at 100 g L-1 of soluble solids. The stock
culture was stored for no longer than 3 weeks at 4 C. These
cultures were grown at the same conditions described
previously.
2.3. Inoculum
The inoculum was prepared from the stock culture, using the
same culture medium. The growth was carried out at 30 C for
21 h in shaker (12.6 rad s-1).