2.5. Sugar utilization by bifidobacteria
An API 50CH sugar utilization kit (BioMérieux, St. Laurent,
QC, Canada) was used to screen the bifidobacteria isolates for
utilization of sugars. In addition, the ability to utilize stachyose
was evaluated using an MRS medium without sugar, as
previously described, with the addition of 0.5% (w/v) filtersterilized
stachyose. Growth was evaluated by comparing the
turbidity of an inoculated tube that was not incubated to that of
one that was incubated for 48 h under anaerobic conditions.
2.6. Data presentation and statistical analyses
Data discussed are the averages from three fermentations.
Analyses of variance were carried out where indicated using
SAS version 8.02 (SAS Institute Inc., Cary, NC, USA).
Comparisons were considered significantly different if pb0.05.
3. Results
3.1. Growth of yogurt starter cultures
Fig. 1 shows the growth pattern and pH changes that
occurred when the two yogurt producing bacteria S. thermo