238 BACTERIOPHAGES 



using phage WLL of Schlesinger, which is related to T2. This 

 phage was concentrated and purified by high speed centrifuga- 

 tion and contained 2.3 X 10^^ particles per mg. dry weight. Its 

 respiration was measured in the Warburg apparatus in various 

 nutrient media, including ammonium lactate-phosphate me- 

 dium and glucose broth, both in the presence and absence 

 of heat-killed bacteria. With amounts of phage varying from 

 1 to 17 mg. per vessel the respiration was negligible. For in- 

 stance, with 1 7 mg. of phage in glucose broth containing 30 mg. 

 of boiled £". co// cells the uptake of oxygen was 0.28 jul. per mg. 

 per hour, in contrast to about 100 for bacteria. Glucose fer- 

 mentation, measured as displacement of CO2 from a bicarbonate 

 buffer, was likewise negligible in comparison with the fermenta- 

 tive activities of E. coli. 



In an attempt to study the respiration of multiplying phage, 

 Schiller measured the oxygen uptake of living host cells in lac- 

 tate-phosphate medium in the presence of an excess of ac- 

 tive or heat-killed phage. There was no detectable difference 

 in respiratory activity whether the phage was active or dead. 

 Schiller also tested 1 mg. amounts of active phage for the pres- 

 ence of the following types of enzymic activity, trypsin, papain, 

 lipase, amylase, maltase, nucleosidase, catalase, urease, arginase, 

 and phosphatase. In tests lasting 24 hours, all results were 

 negative except for phosphatase. The phage preparations were 

 very active in splitting hexosediphosphate and also in hydrolyzing 

 hexosemonophosphate, glycerophosphate, and nucleic acid. The 

 phosphatase activity was inhibited by Af/10 fluoride. It could 

 be greatly decreased by washing the phage with distilled water, 

 and then largely restored by addition of a bacterial filtrate which 

 had little activity itself, suggesting a requirement for some kind of 

 cofactor. It is quite possible that this is bacterial phosphatase 

 which is adsorbed to the phage particles, but if so the adsorption 

 seems to be rather specific. 



A similar study was reported by Ajl (1950) using centrifu- 

 gally concentrated T2 phage. Measurements in the Warburg 

 respirometer using 5 X lO^'^ T2 particles per vessel showed no 



