DORMANCY OF BACTERIAL ENDOSPORE 77 



over a million fold. Such studies would be very interesting with 

 regard to spores of varying states of dormancy. 



The second type of metabolic activity associated with the 

 triggering of germination in activated spores is more readily 

 subject to experimental analysis and has been in large our own 

 approach to the problem. There are essentially two stages 

 involved: (a) an activation reaction which may be reversible and 

 (b) triggered germination of activated spores. 



ACTIVATION 



Activation serves to start the biological clock in germination 

 which under suitable conditions can lead to the loss of heat 

 resistance within a 10-min period. Activation can be achieved 

 in a number of ways: heat shock, chemical agents, storage or 

 mechanical means. The recognizable events of activation are the 

 unmasking of a number of enzyme systems, the loss of some 

 spore components, including DPA. disruption of the integrity 

 of the exosporium and probably an increased permeability. 



Our knowledge of the sequence of events and their relative 

 importance towards poising the system for germination is in- 

 complete. It is not clear whether or not the process is purely 

 physical or may be enzymic. Clearly more work is required in 

 this direction. The activation of the lysozyme-like lytic enzyme, 

 which is active against exosporium and spore walls, might 

 provide an explanation. In B. megatherium-^, Mn-+-initiated 

 germination can be understood by the activation of enzyme 

 activity by Mn-+ and the subsequent liberation of endogenous 

 germinating agents, e.g. L-alanine. 



TRIGGERING REACTIONS IN GERMINATION 



The success of germination is undoubtedly dependent upon 

 the physiological competence of the activated spore. The 

 enzymic nature of germination can be inferred from a number 

 of considerations: 



References p. 94 



