TRACE METAL REQUIREMENTS FOR SPORULATION OF BACILLUS MEGATERIUM.

Kolodziej, Bruno J. (Northwestern University, Evanston, Ill.), and Ralph A. Slepecky. Trace metal requirements for sporulation of Bacillus megaterium. J. Bacteriol. 88:821-830. 1964.-A sucrose-mineral salts medium was purified for the purpose of definitively re-examining the trace metal cations associated with the sporulation of Bacillus megaterium. Two heretofore unknown requirements for copper (0.013 mug/ml of cupric ion) and molybdenum (27.2 mug/ml of molybdate ion) were uncovered. In the purified copper-supplemented medium, sporulation levels of other metals were determined as follows: iron, 0.5 mug/ml of ferrous ion; zinc, 1.1 mug/ml of zinc ion; manganese, 0.037 mug/ml of manganous ion; and calcium, 0.9 mug/ml of calcium ion. The approximate time during which the various metals were required was determined with iron, zinc, calcium, and manganese. A molybdenum substitution for copper, iron, or zinc was noted. The copper requirement was shown for the sporulation of B. cereus var. mycoides and var. albolactis, suggesting that this may be a general requirement for sporulation. The specific functions of metal ions in sporulation are not known, but they probably act as activators of the various enzyme systems necessary for sporulation.