Viability of vaginal probiotic lactobacilli during refrigerated and frozen storage

JUAREZ TOMAS, MARÍA SILVINA; VIRGINIA OCAÑA,; MARIA ELENA FATIMA NADER

ANAEROBE

Academic Press

Lugar: New Jersey; Año: 2004 vol. 10 p. 1 - 5

1075-9964

The viability of six different strains of vaginal probiotic Lactobacillus in two cryoprotective media during refrigerated and frozen storage, two traditional types of stock culture to start of biomass production, was tested. Freezing at ?20 and ?70°C had much less adverse influence on viability than did storage at 7°C. On the other hand, during frozen storage the reduction of viability was greater at higher temperatures. The strains showed variation in the extent of the viability losses during both types of storage. Milk-yeast extract resulted to be the more suitable protective medium to allow lactobacilli viability during the storage of stock cultures. The relatively small influence of the storage in milk-yeast extract at ?70°C on the viability of most of the vaginal Lactobacillus strains indicate that these microorganisms are stable to the storage under these conditions. After 24 m of storage at ?70°C, viable cells of L. paracasei CRL 1251 and CRL 1289, L. crispatus CRL 1266 and L. salivarius CRL 1328 remained above 1 x 108 CFU/ml, or up to 18 m for L. acidophilus CRL 1259.