MANGANESE REQUIREMENT FOR SPORULATION AND OTHER SECONDARY BIOSYNTHETIC PROCESSES OF BACILLUS.

Concentrations of manganese, considerably in excess of the quantity required for normal vegetative growth, are needed by Bacillus for (i) synthesis of such secondary metabolites and structures as antibiotics, D-glutamyl peptide, endospores, bacteriophage, and protective antigen; and (ii) longevity of vegetative cell cultures. No other biologically active element can substitute for manganese, and no secondary biosynthetic process of Bacillus has been found in which the requirement for manganese is absent. In the present study, manganese could induce sporulation of B. megaterium even when added to synthetic broth cultures as late as 100 hr after inoculation. When sub-bactericidal concentrations of various biologically active trace elements were supplied within 2 hr of manganese addition, suppression of spore formation occurred in cultures exposed to elements of group VI (chromium, molybdenum, tungsten, selenium, tellurium) and one of group VIII (nickel); of the six interfering elements, selenium and nickel were most potent.