12 H. O. HALVORSON 



Much of this is due to an improper understanding of the ease 

 with which some of the cells can be made to germinate. Since 

 the germinated cells do show considerable metabolic activity, 

 one needs to exercise extreme care to insure that, in studies on 

 spores, one does not deal with germinated cells-^. 



Before continuing this discussion we need to define our terms. 

 The conversion of a spore to a mature vegetative cell involves 

 two steps. The first, and one that can occur rapidly, involves 

 only the activation of dormant enzyme systems that change the 

 dormant cell to one that has an active metabolism. The second 

 step involves the initiation of growth and finally the emergence 

 of the new vegetative cell. Bacteriologists who are engaged in 

 research on spores limit the term germination to the first step 

 only. 



Several things occur simultaneously in this first change; the 

 loss of refractility, the loss of heat resistance, and the gain of 

 stainability. Recently we have found that the loss of resistance 

 to octyl alcohol occurs, also. Germinated spores or vegetative 

 cells are very sensitive to this chemical whereas spores are 

 extremely resistant. During the initial change, many enzymes 

 that are dormant in the spore become active and begin to 

 function. This will include practically all the enzymes that are 

 needed for energy for growth, such as those concerned in the 

 electron transport system. Thus, clean spores will not show any 

 oxygen uptake with glucose as a substrate, but germinated 

 spores (using this term in the sense in which it was defined above) 

 show a very rapid uptake of oxygen with that substrate. 



A number of agents can be used to trigger this germination 

 process, such as a mixture of aiTiino acids and nucleotides, with 

 or without previous heat shock, depending upon the species and 

 past history of the spores. Some spores can be germinated with 

 single amino acids, others with nucleotides alone, and some with 

 various kinds of chelating agents. Regardless of the trigger 

 mechanism used, dipicolinic acid, calcium ions, and some 

 polypeptides are released from the spore simultaneously with 

 the activation of the enzyme. Most workers believe that the 



