For enumeration of L. bulgaricus, the medium RCA
pH 5.3 incubated at 45 C under anaerobic conditions was
considered effective, since the other cultures were inhibited under
these conditions. With respect to the enumeration of
S. thermophilus, ST agar incubated at 30 C under anaerobic conditions
was selective, since no growth of lactobacilli strains was
observed.