The nutritional requirements for germination and outgrowth of spores of thermophilic bacteria

During the last 10 years the subject of bacte-rial spore germination has been intensively inves-tigated. In most of these studies it has been found that bacterial spores are capable of germination under conditions which do not permit the germi-nated form to survive (Schmidt, 1955; Stedman, 1956). Hills (1949) pointed out that a distinction must be drawn between the requirements for germination and those for growth. He felt that the requirements for germination are more exact-ing than those for growth, since adenosine stimulated germination but not growth of Bacil-lus anthracis. Pulvertaft and Haynes (1951) in studies on the effect of adenosine on spore germi-nation of Bacillus cereus and Bacillus subtilis concluded that newly germinated bacilli were more exacting in their growth requirements than bacilli developing from vegetative forms. Amaha and Sakaguchi (1952) studied the nutritional requirements of vegetative cells and spores of Bacillus natto, B. subtilis, Bacillus megaterium I and II, Bacillus mycoides, and B. cereus. They found that the vegetative cells of all strains and the spores of B. subtilis and B. my-coides did not require any of the eighteen amino acids tested. However, B. natto spores required isoleucine, and B. cereus spores required valine. B. megaterium I spores required alanine and threonine, and the spores of B. megaterium II re-quired phenylalanine. This paper is concerned with a comparative studv of the nutritional requirements for spore germination and outgrowth and vegetative cell growth of Bacillus stearothermophilus, Bacillu