The effect of bacitracin and Mn(II)ions upon the producer strain Bacillus licheniformis.

The peptide antibiotic bacitracin is inhibitory to growth of the producer strain Bacillus licheniformis only in the presence of excess manganese(II)ions. Both the early and the late growth are inhibited in a similar manner upon addition of bacitracin and manganese(II)ions. Thus, B. licheniformis does not develop resistance to its own antibiotic during growth. Added bacitracin is stimulatory to growth of B. licheniformis in media with a very low content of manganese(II)ions. These results support the hypothesis that bacitracin participates in the manganese transport of the producer strain B. licheniformis.