DISSOCIATION OF SPORE GERMINATION FROM OUTGROWTH BY USE OF AUXOTROPHIC MUTANTS OF BACILLUS SUBTILIS

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Abstract
Inoculation of resting spores of uracil-less, phenylalanine-less, and nicotinic acid-less B. subtilis mutants into a defined medium (glucose, alanine, asparagine, glutamic acid, and mineral salts) leads to the production of viable, germinated spores which do not undergo outgrowth. In the same medium, wild-type spores germinate and grow into vegetative cells. The mutant germinated spores are labile to both heat and lysozyme. They retain their viability for at least 12 hr. after germination in this medium. On agar plates containing the same medium, germinated spores remain viable in the absence of their growth factor for at least 3 days. The germinated spores were compared to resting spores and vegetative cells as to resistance to killing caused by incubation in mineral salts mixture, in phosphate, and in water. Spores were completely resistant to all 3 treatments. In salts mixture and in phosphate, germinated spores were killed but at a lower rate than vegetative cells. In water, both type cells rapidly lost viability.