Dependence of Bacillus stearuthermuphilus Spore Germination on Nutrient Depletion and Manganese

Spores of Bacillus stearothermophilus NCTC 10003 germinated without delay in glucose/gluta-mate chemically defined medium at 60°C. The nature of the nutrient limitation inducing sporulation affected the ability of spores to germinate under the conditions studied. Spores produced after glucose depletion of the medium (carbon-depleted spores) germinated faster and to a greater extent than did spores produced after sulphate depletion of the medium (sulphur-depleted spores). Sub-lethal heat treatment (80 "C, 10 min) prior to germination enhanced dormancy. L-Alanine (0.2 mg ml-I) did not reverse this effect, nor did it enhance the germina-tion of sulphur-depleted spores. The rate and extent of germination for both kinds of spores was proportional to the intrasporal manganese concentration. In contrast, extrasporal manganese exerted an inhibitory efYect and it was not required for germination. We conclude that the nature of the nutrient depletion and the level of intrasporal manganese distinctly affect the extent and rate of spore germination