Spore germination in the genus Bacillus: the modification of germination requirements as a result of preheating

Abstract

SUMMARY: Spore suspensions of Bacillus megaterium germinated spontaneously after heat treatment. The extent of germination depended on the degree of close packing of the suspension, the temperature and duration of heating, and on the presence of water. Spontaneous germination was not inhibited by heating with cyanide, azide, 2: 4-dinitrophenol or sodium iodoacetate, but was significantly inhibited by sodium fluoride. Freshly harvested spores of a laboratory strain of Bacillus cereus required either inosine or a mixture of alanine + tyrosine + adenosine for optimal germination. After prolonged storage or a short heat treatment, adenosine alone stimulated rapid and complete germination. Heat activation did not occur in the absence of water. It was inhibited to some extent by sodium fluoride. Similar results were obtained with B. cereus, NCTC 8035. After preheating, spores of a virulent and an avirulent strain of Bacitlus anthracis germinated more rapidly and completely in a mixture of adenosine + tyrosine + alanine, but not in adenosine alone. Inoaine stimulated rapid and complete germi