The relationship between the cleavage of purine ribosides by bacterial spores and the germination of the spores

Since adenosine is required for the initiation of rapid germination of spores of several species of the genus Bacillus (Hills, 1949; Stewart and Halvorson, 1953; Church et al., 1954; Lawrence, 1955) including a strain of Bacilus cereus var. terminalis, it appeared worth while to investigate the role of adenosine in the germination process. It has been found (Lawrence, 1955) that spores of B. cereus are capable of cleaving adenosine to yield adenine and ribose. It is the purpose of this report to compare the conditions optimum for cleavage of adenosine with conditions optimum for germination, to evaluate the effects of related nucleic acid deriva-tives and to describe the correlation between the germination requirements of certain spores and their ability to cleave adenosine. MATERILS AND METHODS Washed and dried spores of B. cereus var. terminalis were obtained from the batch described by Stewart and Halvorson (1953). Clean dry spores of Bacillus globigii and of Bacillus polymyxa were obtained through the courtesy of Dr. Harlyn Halvorson. The spores were stored at-20 C until they were used. Germination of the spores in liquid media was followed by noting the decrease in plate count at 37 C after heating at 80 C for 5 minutes and by measuring the increase in per cent transmission at 630 m,u in the Lumetron colorimeter model 402 (Powell, 1951). The nucleic acid derivatives were commercial products and were essentially pure as tested chromatographically. The analytical procedures used are described by Lawrence (1955). EXPERIMENTAL RESULTS The effectiveness for germinaton of compounds relaed to L-alanine. It has been found (Stewar