[Instability of the auxotrophic markers in Bacillus thuringiensis]

Auxotrophic mutants of Bacillus thuringiensis have been isolated and compared with the mutants of Bacillus subtilis. It has been found that after spore formation and a prolonged storage, the considerable part of cells in a population of some strains display a genetically unstable additional requirement for arginine with high frequency. The correlation between tetracycline sensitivity and unstable requirement for arginine and other growth factors has been found. The possible reasons for instability of genetic markers in Bac. thuringiensis are discussed.