[Viability study of actinomycete cultures preserved for a long time on agar media]

Viability of 254 actinomycetous strains stored for 1 to 6 years on agarized media a temperature of 4-10 degrees C without passages was studied. The cultures included 204 strain of Actinomyces, 26 strains of Mycobacterium, 2 strains of Streptosporangium, 1 strain of Intrasporangium, 2 strains of Micropolyspora and 5 strains of Thermoactinomyces. Most of the cultures, i.e. 94.55 per cent stored for 6 years remained vialbe after the this period. With an increase in the storage period from 1 to 4 years the number of the viable cultures stored for such periods of time gradually decreased from 95.28 to 73.11 per cent. The representatives of Micromonospora and Streptosporangium, some strains of Proactinomyces and the cultures of Actinomyces forming whorl sporophores were the least stable when stored for a period up to 1 year. It was noted that viability of different strains within the same species was not the same in storage.