Further studies on so-called bacteriophage.

Abstract

D'Herelle's hypothesis as to the parasitic nature of the “bacteriophage” is questioned by a number of investigators. However, the evidence which would definitely disprove its animate nature is still lacking. It seemed to us that the question of the nature of the bacteriophage might be approached by the study of its metabolism. The behavior of the bacteriophage with regard to respiration was first studied.

Different amounts of bacteriophage, representing from 5×10¹⁰ to 1×10¹⁵ active units, were placed in a microrespirometer, constructed on the general principle of the respirometer of Professor Osterhout, for varying periods of time up to 96 hours at 22° C. It was found that neither entire active filtrates nor the precipitated substance produce any CO₂ in the presence of oxygen. The method used was sensitive enough to indicate production of CO₂ under similar conditions by several viruses and bacteria, some of which had been kept in dry state for a period of years. In many instances, particularly in the case of fresh tissue emulsions and of bacteria dried over H₂SO₄ for 24 hours, CO₂ production could be detected 2 to 3 hours after placing minute amounts (0.001 gm.) of material in the apparatus.