[The interaction of Escherichia coli, possessing the antilysozyme trait, with infusoria].

In this work isogenic E.coli strains K-12J53 and J53pAlz60, differing in the presence of the antilysozyme characteristic, were used. In the process of joint cultivation the degradation of lysozyme in protozoa by antilysozyme-active E.coli was established. The initial culture of antilysozyme-active E.coli K-12pAlz60 was found to be slightly heterogeneous with respect to the antilysozyme characteristic; this heterogeneity increased after the interaction of E.coli with protozoa. As the result of their joint cultivation with Tetrahymena, clones with low (2 micrograms/ml) antilysozyme activity (ALA) disappeared from the population and clones with medium and high values of ALA (3, 4, 5, 6 micrograms/ml) accumulated. The dynamics of the interaction of infusoria with Escherichia cells (ALA+) on the ultrastructural level in 1-6 and 24 hours revealed the gradual increase of processes leading to the destruction of most of the bacteria (up to their complete digestion) and, at the same time, the presence, observed also at an early period, of intact bacteria, resistant to lysis, whose survival was ensured by their antilysozyme characteristic.