The effect of potassium sorbate on growth of two strains of Pseudomonas putrefaciens (Alteromonas)1 was studied. Addition of 0.2% sorbate to trypticase soy broth (pH 6.0) inactivated strain P19X and resulted in a 3-log cycle reduction in number of viable cells of strain P5LIN through 6 days of incubation at 24 C.