Manganese as an Essential Element for Sporulation in the Genus Bacillus

Abstract

Using the filter paper disk diffusion assay technique as a tool in our antibiotic screening program, occasional samples have been encountered that were without inhibitory activity but induced a marked stimulation of the test organism, Bacillus subtilis, ATCC 6633. This effect was manifested as a zone of heavy growth in the region of the plate surrounding the disk saturated with the sample under test and was sharply demarcated from a less dense background. Low power microscopic examination of the area revealed larger surface colonies in the stimulated area. Within this stimulated zone, occasional subsurface colonies could be seen that were comparable in size with the smaller colonies in the area outside the stimulated zone, suggesting that stimulation of growth occurred only under conditions of strict aerobiosis. When an extract of Streptomyces sp mycelium became available that consistently produced the effect, an attempt was made to isolate the stimulatory factor. It was found that an acid extract of the ash of the sample contained the active principle. Tests with various inorganic ions revealed that manganese salts SUMMARY Manganese has been shown to stimulate sporulation of several species of the genus Bacillus. Sporulation is specifically dependent upon the presence of manganese at a concentration greater than that required for full vegetative growth of BaciUus subtilis, ATCC 6633, which was studied further as a representative of the genus.

ALTERATIONS IN METAL CONTENT OF SPORES OFBACILLUS MEGATERIUMAND THE EFFECT ON SOME SPORE PROPERTIES

“…manganese; nonaddition of manganese to the growth medium led to nonsporulating cells, as discovered by Charney et al (1951). Nonaddition of zinc or calcium resulted in diminished sporulation.…”

Manganese homeostasis in Bacillus subtilis is regulated by MntR, a bifunctional regulator related to the diphtheria toxin repressor family of proteins

“…It has been known for many years that Mn(II) is required for sporulation in Bacilli (Charney et al ., 1951). To determine if perturbations of Mn(II) homeostasis affect sporulation, we tested our various mutant strains for their ability to sporulate both on plates and in liquid culture.…”

Magnesium‐dependent processes are targets of bacterial manganese toxicity

“…Manganese can also substitute for iron in class I ribonucleotide reductase under conditions where iron is limited and manganese is available (Martin and Imlay, 2011). In addition, it is required for sporulation in Bacillus subtilis (Charney et al, 1951) and the stringent response in Escherichia coli (Potrykus and Cashel, 2008).…”