Adsorption of Bacteriophages to Homologous Bacteria 



II. Quantitative Investigations of Adsorption Velocity and Saturation. 

 Estimation of the Particle Size of the Bacteriophage 



By 



M. SCHLESINGER 



Institute for Colloid Research, Frankfurt A.M. 



It was shown in the preceding communication that bacteriophages of a lysate 

 do not represent a uniform population; instead they are composed of several 

 classes of widely varying adsorbabilities. The following equation expressing the 

 kinetics of adsorption of phages to homologous bacteria was derived : 



71 



2.3 log - = kht , (1) 



nt 



where no represents the initial concentration of free phage, n« the concentration 

 after a reaction time t and h the concentration of bacteria per ml. However, this 

 equation is applicable only to experimental conditions under which the observed 

 change in the concentration of free bacteriophages is mamly due to the adsorption 

 of a single class of particles of uniform adsorbability. Lysates of the coli 88 bac- 

 teriophage employed in our experiments were found to consist almost entirely of a 

 uniform class of rapidly and irreversibly adsorbable phages when conditions were 

 such that the concentration of sensitive bacteria and the reaction time was varied 

 only within limits that allowed the decrease in concentration of free phage not to 

 exceed 90 to 95%. 



It shall be shown in this communication that under these conditions equation 

 (1) is so well satisfied that wide variations of the different experimental param- 

 eters produce no change in the value of the velocity constant k calculated from 

 the experimental results. After establishing the value of k for adsorption to dead 

 as well as to living bacteria, experiments will be presented that are designed to 

 determine the bacterial "saturation capacity", i.e. the number of phage particles 

 that a single bacterial cell can adsorb. Finally, an attempt will be made to calculate 

 the particle size of the phage from the adsorption velocity constant. Further 

 insight shall be gained into the adsorption mechanism by a comparison of the 

 values so calculated with the results of direct determinations of the particle size. 



Translated from the German and reprinted by permission of 



the Springer Verlag from Zeitschrift fur Hygenie und 



Immunitaetsforschung, 114, 149-160 (1932). 



26 



