Conclusions
Under the conditions of this study, it was found that the MRS
containing bile was selective for enumeration of L. acidophilus La5
from yoghurt, while RCA agar pH 5.3 and ST agar were effective for
enumeration of L. bulgaricus and S. thermophilus, respectively. For
the probiotic Prato cheese, the effective culture medium for
enumeration of L. acidophilus was the MRSS incubated at 45 C for 72 h under anaerobic conditions, while M17 agar containing lactose
and incubated at 30 C under aerobic conditions was effective for
enumeration of Lactococcus lactis.
For obtaining reliable results in the selective enumeration of
probiotic microorganisms in fermented dairy products is necessary
to evaluate different methods, both for the product under study and
pure cultures, since the presence of different strains may compromise
the results, and therefore lead to misleading conclusions
about the presence and number of probiotics in dairy products