BERNARD L. STREHLER 



221 



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TEMPERATURE CO 



Fig. 8. Effect of temperature on bacterial extract luminescence. 1.0 ml bacterial 

 extract (2%); 1.0 ml phosphate buffer, pH 7.0, 0.01 M; 2.0 mg DPNH^. 

 The sample was cooled to 0° C, and its temperature was then raised rapidly 

 with stirring by immersing in hot water (ca. 40° C). Readings were made 

 for 10 seconds at each temperature. Total time for eight determinations, 10 

 minutes. 



fact being indicated, since such a high activation energy would hardly 

 permit the reaction to proceed at significant rates. Possibly a large 

 entropy factor is involved, although another alternative, in such a 

 complicated concatenation of steps as seems to exist, is that nonlumi- 

 nous alternative pathways compete more effectively at lower tempera- 

 tures. 



Various agents have been examined for inhibitory action. Some of 

 those tested are indicated in Table II, while Fig. 9 illustrates the effect 

 of ultraviolet light (Strehler and Cormier, 1953). According to McEl- 

 roy ( private communication ) , this initial stimulatory effect of ultra- 



