The effect of ribonuclease on phage-host interaction

SUMMARY: Pancreatic ribonuclease inhibits the multiplication of a Rhizobium bacteriophage in liquid bacterial cultures by preventing permanent combination between phage and host. The addition of ribonuclease after phage has already combined with the bacteria does not prevent phage from multiplying, but it does decrease the rate of multiplication; the enzyme also interferes with multiplication of the bacteria. Experiments with ribonuclease in conjunction with chymotrypsin suggest that phage and bacteria unite in the presence of ribonuclease but that the union is only transitory and ends by the release of still active phage. In the presence of chymotrypsin, however, the phage becomes inactive during this transient union.