Possible functions of peptide antibiotics during growth of producer organisms: bacitracin and metal (II) ion transport.

The inhibitory effect of bacitracin upon growth of the producer strain Bacillus licheniformis ATCC 10716 was dependent upon the presence of several different metal (II) ions, particularly Mn (II), Co (II), or Zn (II) ions. This supports our previous suggestion that the normal function of bacitracin during growth of the producer organism may be to promote the uptake of several divalent metal ions. Due to the striking similarity between the antimicrobial effect of bacitracin towards susceptible organisms and the effect of bacitracin towards the producer organisms B. licheniformis ATCC 10716, the possibility that the antimicrobial effect of bacitracin may be an induction of uptake of toxic amounts of metal ions is discussed. The possibility that peptide antibiotics may normally participate in ion transport during growth of producer organisms is also discussed.