Studies on Induction of Mutations by Heat in Spores of Bacillus Subtilis

Previous studies have demonstrated that heating dry spores induced the formation of a high proportion of mutants. In this paper, a study was made of the correlation between the temperature of the heat treatment and the proportion of auxotrophic mutants induced. This proportion was found to increase between 105° and 115°, and then to decline (115°–155°). The proportions of auxotrophs for individual amino acids reached maxima at various temperatures.