Abstract
The biosynthesis of bicyclomycin by Streptomyces. rapporonensis was studied using suspensions of washed mycelium. Nicotinamide and Fe2+ were found to be essential cofactors in the biosynthesis. Production of bicyclomycin was enhanced most effectively in the presence of equal moles of L-leucine and L-isoleucine, which in experiments with radioactively labeled compounds were found to be incorporated into bicyclomycin at equivalent rates. These facts strongly suggest that bicyclomycin biosynthesis involves coupling of equal moles of these two amino acids.