Action of chloramphenicol and its isomers on secondary biosynthetic processes of bacillus

Chloramphenicol or its isomers, if supplied within 4 hr after the addition of Mn⁺², prevented sporulation of Bacillus megaterium at concentrations that partially inhibited protein synthesis but which were neither bacteriostatic nor bactericidal. Likewise, sub-bactericidal quantities of the compounds, if supplied within 2 hr after the addition of Mn⁺², suppressed formation of bacitracin by B. licheniformis. In contrast to previous reports that chloramphenicol is less active than its isomers against sporulation and peptide formation, the results of the present study indicated that the order and extent of these activities of the compounds is similar to that of their ability to prevent growth and to suppress protein synthesis; i.e., d(-)-threo > l(+)-erythro > d(-)-erythro.