Isolation and characteristics of a short rod-shaped mutant of Pseudomonas aeruginosa

Abstract Among 40 short rod-shaped mutants of Pseudomonas aeruginosa PAO isolated after nitrosoguanidine mutagenesis, a stable clone designated KG1034 was obtained and studied for its cellular and genetical features. Cells of the parent strain, PAO2302 had a mean cell length of 1.9 μm, whereas that of KG1034 was 1.3 μm. The doubling time of KG1034 was less than that of the parent strain, although both strains elongated at the same rate and exhibited the same relative amounts and pattern of penicillin-binding proteins. These results suggested that the phenotype of KG1034 was due to the initiation of septation at an earlier stage. The new gene responsible for this phenotype was named srs (abbreviation for short r od shape) and mapped by conjugation between cys -54 and puuC .