Adenine nucleotide pool and energy charge during growth of a tyrothricin-producing strain of Bacillus brevis.

The adenine nucleotide levels and derived energy charge value of a tyrothricin-producing strain of Bacillus brevis under aerobic conditions were in good agreement with published values for other bacteria. When growing cultures of B. brevis underwent a transition from aerobic to anaerobic conditions, cyclic variations in the level of adenine nucleotides were observed and the energy charge value oxcillated between 0.87 and 0.70. The significance of these changes is considered in relation to antibiotic production as a possible regulatory mechanism in energy metabolism. It is concluded that tyrothricin is not directly involved in the observed changes in energy charge value.