[Experiment to study some suspension media for the lyophilization of actinomycetes]

Viability and cultural properties of 59 actinomycetes and 17 bacteria lyophilized in polyvinylpyrrolidone (PVP), sodium glutamate, their combinations and horse serum were studied after storage for 2 years at a temperature of 4-10 degrees. A 5 per cent solution of sodium glutamate had a high protective effect on viability of the above organisms. The solution containing 3 per cent of sodium glutamate and 3 per cent of PVP was somewhat less effective. The cultures lyophilized in 5 per cent solution of sodium glutamate had the same viability levels as those lyophilized in horse serum, while the latter had better growth rates on their plating out on nutrient media. A 5 per cent solution of PVP had no advantages over sodium glutamate or horse serum with respect to preservation of the organism viability. No significant differences in the cultural properties: colour of the aerial and substrate mycelium and pigment production were noted in the actinomycetes lyophilized in various protective media and the analogous control cultures maintained by means of passages on fresh nutrient media.