Research Methods

SUMMARY: A strain of Bacillus megatherium has been isolated which requires glucose specifically for optimal spore germination. Cyanide, fluoride, iodoacetate, eitrate, oxalate, azide, and 2: 4-dinitrophenol were ineffective as inhibitors of ger-mination in glucose, while 8-hydroxyquinoline inhibited completely at 10 m ~. The inhibitory effect of glucose on sporulation of the organism in liquid and solid media is described. It has been found (Hills, 1949a) that a simple medium containing L-alanine, tyrosine, and adenosine provides practically optimal conditions for germina-tion of certain strains of Bacillus anthracis. The germination of a laboratory strain of B. subtilis in a buffered medium containing L-alanine only has also been described (Hills, 1950; Powell, 1950). An attempt is now being made to discover the germination requirements of other sporing bacteria; the criterion of germination is again taken as loss of heat resistance, accompanied by change in staining properties and refractivity. In the present report, the sporulation and germination of a strain of B. rnegathrium freshly isolated from air are described. The spores of this organism have been found to require glucose specifically for optimal germination, which proceeds to 80-90 yo completion in 30 min. at 35 ' a t spore concentrations up to 2.5 x 10g/ml. A complete systematic investigation of the factors affecting sporulation of this organism has not been made. The effect of adding excess glucose to the medium with and without aeration has been observed, but, as Knaysi ( 1 9 4 5 ~) points out, the factors affecting sporulation are complex and interrelated, so that these observations must be regarded as incomplete