Altered sporulation and respiratory patterns in mutants of Bacillus subtilis induced by acridine orange.

Bott, K. F. (The University of Chicago, Chicago, Ill.), and R. Davidoff-Abelson. Altered sporulation and respiratory patterns in mutants of Bacillus subtilis induced by acridine orange. J. Bacteriol. 92:229-240. 1966.-The addition of acridine orange to vegetative cultures of Bacillus subtilis induces the formation of sporulation mutants at a frequency of 20% or greater. These mutants are grouped into seven categories which reflect their different morphological properties. They are altered in their vegetative metabolism, as indicated by abnormal growth on synthetic media. Sporulation of these mutants is impaired at several levels, all of which are stable upon repeated subculturing. The initial stages of sporulation which require no increased metabolic activity (proteolytic enzyme activity and antibiotic production) are functional in all strains, but glucose dehydrogenase activity, an enzyme associated with early synthetic functions in spore synthesis, is significantly reduced. Reduced nicotinamide adenine dinucleotide oxidase is slightly depressed. It is suggested that acridine orange interacts with a cellular constituent controlling respiration and consequently prevents an increased metabolic activity that may be associated with normal spore synthesis.