REQUIREMENTS FOR PHAGE PRODUCTION 239 



detectable oxygen uptake with succinate, fumarate, malate, 

 pyruvate, acetate, or glucose as substrates. An equal amount 

 (4.5 mg. dry weight) of E. coli cells catalyzed the uptake of 100 

 to 200 ^il. of oxygen in 2 hours with these substrates under the 

 same conditions. Similar experiments using 8.6 mg. of phage 

 with glutamic or aspartic acids resulted in no detectable oxygen 

 uptake, CO2 evolution, or NH3 liberation. Dehydrogenase ac- 

 tivity was measured in Thunberg tubes using methylene blue at 

 1 :5,000 to 1 :50,000 and phage at 5 X 10^2 particles per tube. 

 There was no detectable reduction of the dye in 6 hours using 

 glucose, succinate, malate, or boiled E. co/z juice as substrates. 



No endogenous CO2 production and no CO2 evolution from 

 glucose could be detected, but pyruvate and oxalactate as sub- 

 strates yielded considerable amounts of CO2. However, this 

 was readily demonstrated to be nonenzymatic in nature because 

 boiled phage was more active than unhealed phage. Prelimi- 

 nary experiments indicated that concentrated phage preparations 

 did contain some ATPase activity, but no quantitative results 

 were given and it is not clear whether this is a true property of the 

 phage or due to a contaminating bacterial enzyme. With this 

 single exception, all experiments were in agreement in that they 

 failed to yield evidence for metabolic activity in mature phage 

 particles. 



Similar studies on concentrated preparations (5 X 10^^ ^^ly- 

 ticles/ml.) of staphylococcus phage have been reported by Price 

 (1952) but without details. "Tests for all the reactions in gly- 

 colysis and those in the Krebs cycle were negative." Price also 

 stated that there was no oxidation of gluconic acid, amino acids, 

 or fatty acids 



Putnam (1953) reported that Kozloff (private communication) 

 was unable to detect the presence in phage T6 of glycerol phos- 

 phatase, phenolphthalein phosphatase, DNAase, ATPase, or 

 protease. These results are in conflict with those of Schiiler and 

 Ajl, who used closely related phages. 



One may safely conclude that up to the present there is no 

 unequivocal evidence for the existence of any enzymic activity 



