The effect of streptomycin on cell size of a strain of Pseudomonas aeruginosa

Abstract

Washed cells of a strain of Pseudomonas aeruginosa rapidly decrease in size when they are put in salt solutions and then upon incubation increase in size. In the presence of streptomycin (10 μg/ml) this increase is followed by a decrease but only if ammonia has been assimilated by the cells in the presence of an oxidizable substrate. The extent of the decrease caused by streptomycin is proportional to the amount of ammonia assimilated and also the concentration of the salt solution. Chlortetracycline (0.02 μg/ml), chloramphenicol (1.0 μg/ml), and cycloserine (10 μg/ml) completely inhibit the streptomycin effect when added before or after ammonia assimilation is complete.