[Features of dynamics of growth and formation of uncultivable forms in Lactococcus lactis]

Study strain differences in dynamics of viability and formation of uncultivable forms of Lactococcus lactis.

3 strains of L. lactis--MSU, 729 and F116 were used in the study. Uncultivable forms were obtained by prolonged incubation of cultures of lactococcus in synthetic medium under conditions of carbohydrate deprivation. Medium was inoculated by cultures grown in Elliker broth, washed by saline and without washing. The populations obtained were incubated at 30 degrees C without mixing for 4 months. Samples of cultures were studied periodically for viability and cultivability.

In cultures obtained by using unwashed inoculate active growth of quantity of bacteria in the first days after seeding was noted. Speed of formation of uncultivable forms is the faster the higher the level of metabolic activity of cells in the population. A fact of phenotypic dissociation in lactococcus culture under stress was detected.

The speed of formation of uncultivable forms of L. lactis, as well as stability of their existence may probably depend on the strain, cultivation conditions and metabolic activity of cells in the population.