Evaluation of culture media for enumeration of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium animalis in the presence of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus.

KATIA GIANNI DE CARVALHO LIMA; MONIKA FRANCISCA KRUGER; JORGE BERHENS; MARIA TERESA DESTRO; MARISA LANDGRAF; BERNADETTE DORA GOMBOSSY DE MELO FRANCO

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2009 vol. 42 p. 491 - 495

0023-6438

The study compared the growth capability of probiotic (Lactobacillus acidophilus La05, Lactobacillus casei Lc01 and Bifidobacterium animalis Bb12) and non-probiotic (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus) cultures on twenty-one culture media grouped according to selectivity: nonselective agars, selective agars without antibiotics and MRS agars containing different combinations of lithium chloride, cystein, bile salts and antibiotics. Four of these media were selected for quantitative enumeration of L. acidophilus La05, L. casei Lc01, and B. animalis Bb12. The best culture media and incubation conditions for enumeration of the probiotic cultures were: B. animalis: MRS agar with dicloxacillin, 37°C or 42°C, anaerobiosis; L. acidophilus: MRS agar with bile salts, 37°C or 42°C, aerobiosis; L. casei: MRS agar with lithium chloride and sodium propionate, 37°C or 42°C, aerobiosis or anaerobiosis. Plating on MRS with glucose replaced by maltose, 37°C or 42°C, anaerobiosis, will distinguish probiotic from nonprobiotic cultures. For enumeration of each probiotic in a mixed culture, the following media and incubation conditions were recommended: B. animalis: 4ABC MRS, 42°C, anaerobiosis, L. acidophilus: LC medium, 42°C, aerobiosis or anaerobiosis and L. casei: LP MRS, 42°C, aerobiosis or anaerobiosis. In all experiments, differences in counts using pour plating or surface plating were not significant (P > 0.05).