Effects of mutational loss of specific intracellular proteases on the sporulation of Bacillus subtilis.

Two protease-deficient mutants of Bacillus subtilis 168 (Trp(-)) were isolated and compared with the parental strain with respect to production of intracellular proteases and sporulation. A mutant lacking the metal-requiring "neutral" protease intracellularly sporulated as well as the parental strain. A second mutant, deficient in an as yet uncharacterized intracellular protease, failed to sporulate normally. It is proposed that this new protease is also involved in intracellular protein turnover.