ADSORPTION OF THE WILD-TYPE BACTERIOPHAGE-PM2 AND ITS WIDE-HOST-RANGEMUTANT ON WILD AND MUTANT STRAINS OF ALTEROMONAS-ESPEJIANA

Rate constants were determined for the adsorption of the wild-type bac teriophage PM2 (phage w) and its wide-host-range mutant (phage r) on c ells of Alteromonas espejiana BAL-31 (strain B) and its phage w-resist ant, phage r-susceptible mutant (strain C). The constants equaled 3 x 10(-9) ml/min (for w + B and r + B) and 3 x 10(-10) ml/min (for r + C) . In all cases, the adsorption was energy-dependent: the adsorption ra te decreased by an order of magnitude in the presence of 5 mM NaCN. Th e residual adsorption was reversible. Type B bacteria possessed approx imately 140 receptors for phage w per cell; the number of receptors fo r phage r on type C cells varied from 150 to 160 per cell, the differe nce being within the accuracy of measurements. Possible mechanisms of the energy-dependent adsorption of bacteriophage PM2 on host cells are discussed.