[Comparative physiology of the replication of RNA-containing bacteriophages MS2 and Q beta]

The yield of the phage QB is always less than the yield of the phage MS2, the conditions of cultivation being similar. This is due to the fact that the yield of the phage QB from an infection centre is lower by a factor of 5--10 than the yield of the phage MS2. The yield of the phages may be increased by optimizing conditions of cultivation. The RNA-containg phages MS2 and QB were cultivated in the peptone-yeast growth medium in fermenters with the working volume of 30 and 50 litres. The yields were 2--5-10(13) particles/ml and 1--4-10(12) particles/ml for the phages MS2 and QB, respectively. The specific infectiveness of purified phage preparations was 2--4-10(12) particles/OD260 (MS2) and 2--4-10(11) particles/OD260 (QB).