Accidental Selection and Intentional Restoration of Sporulation-Deficient Bacillus anthracis Mutants

We demonstrate the frequent accidental enrichment of spontaneous sporulation-deficient mutants of Bacillus anthracis on solid medium and identify contributing factors. Mutations in spo0A, encoding the master regulator of sporulation initiation, were found in 38 of 53 mutants. Transductions using bacteriophage CP51 propagated on sporogenic bacteria allowed for the restoration of sporulation phenotypes.