THE BIOCHEMICAL NATURE OF THE 

 DORMANT STATE IN THE BACTERIAL ENDOSPORE* 



H. HALVORSON, R. O'CONNOR AND R. DOI 



Department of Bacteriology, University of Wisconsin, Madison, Wise. 



(U.S.A.) 



The biochemical nature of the dormant state of bacterial 

 endospores might seem at first to be a contradictory statement 

 since the dormant state is generally associated with the absence 

 of metabolic activity. This situation is particularly true of the 

 bacterial endospore which is probably the most nearly inert 

 biological system known. A biochemical description of the 

 dormant state must include an analysis of those chemicals whose 

 inclusion is essential to the production and maintenance of 

 dormancy as well as the enzymic reactions available for trigger- 

 ing the breaking of dormancy. 



THE CHEMICAL NATURE OF THE DORMANT STATE 



A number of quantitative chemical differences have been 

 observed between spores and vegetative cells^. The spores have 

 lower levels of D-amino acids, free amino acids, lipid, poly- 

 saccharide, RNA and water whereas they have higher levels of 

 total nitrogen, protein-bound phosphorus and labile protein- 

 bound phosphorus. Our knowledge of the water content of 

 spores is unsatisfactory. Henry and Friedman- reported that 

 B. megatherium spores contained 58 % water whereas the 

 vegetative cells contained 80% water based on weight after 

 drying. Ross and Billing^, employing refractive index measure- 

 ments, observed values for spores comparable with those of 

 dehydrated proteins suggesting that spores are essentially 



* This investigation was supported in part by a research grant of the 

 Wisconsin Alumni Research Foundation and in part by a grant from the 

 Brown-Hazen Fund. 



References p. 94 



