THE BACTERIAL ENDOSPORE 57 



cells look abnormal, and, in fact, many of them lyse before they 

 can begin to produce spores. This inhibitor may very well 

 interfere with the synthesis of cell walls. If the inhibitor is added 

 after the pH has started to rise (at which time the production of 

 vegetative cells has been completed and presumably there is no 

 further synthesis of cell wall), we find that the inhibitor does not 

 interfere with the production of spores; but the spores which 

 are produced are heat sensitive, as shown in Table XI. In fact, 



TABLE XI 



THE EFFECT OF TIME OF ADDITION OF DIETHYL PIMELATE (0.01 M) 



ON SPORULATION 



After 24-h incubation at 30° on shaker 



pH of culture at Viable Octyl alcohol stable Heat stable 



time of addition ( cells j ml) (cellsjml) ( cells j ml) ^ 



For purposes of counting, cells were spun down and resuspended in 0.01 M 

 phosphate buffer, pH 7.2. 



Vegetative cells and germinated spores are killed immediately on exposure 

 to octyl alcohol (0.06 ml 100 ml H2O). 



the results are almost identical with those obtained with ethyl 

 oxamate. Here again, more than 95 % of the spores are heat 

 sensitive. These heat-sensitive spores appear to be perfectly 

 normal, as far as staining is concerned. They are refractile like 

 normal spores; they undergo germination with ordinary germi- 

 nation nutrients, as normal spores will; and they are resistant 

 to octyl alcohol. They are extremely sensitive to heat, most of 

 them being killed at 65' in less than 15 min. Their heat resist- 

 ance is no greater than that in vegetative cells. 



References p. 59 



