Factors Affecting L-Alanine Induced Germination of Bacillus Spores

Abstract

The effect of temperature, pH, cations, and caramelized sugars on L-alanine-induced germination of Bacillus licheniformis and B. cereus-7 spores was investigated. The germination of B. licheniformis spores was optimal at higher temperatures, with more than 99% germination at 37 and 55 C, but none at 21 C. B. cereus-7 spores germinated optimally at 37 C, slowly at 21 C, and much more slowly at 55 C. The optimal pH for L-alanine induced spore germination in both Bacillus species was pH 7.0. Germination for B. cereus-7 spores was more sensitive to pH than B. licheniformis. With regard to the effect of ionic-inducement, for B. licheniformis potassium did not affect germination, but the divalent cations calcium and magnesium inhibited germination, especially at 100 mM concentrations. Ferric ion inhibited germination at the lower concentrations but as the concentrations increased, this inhibitory property was lost. For B. cereus-7 spores, potassium, calcium, and magnesium were inhibitory to germination. Ferric ion was also inhibitory at the lower concentrations but was stimulatory at 50 mM and higher. None of the caramels from four sugars (glucose, fructose, galactose, and lactose) affected L-alanine-induced germination of spores of B. licheniformis or B. cereus-7. © 1974, American Dairy Science Association. All rights reserved.