216 



BIOCHEMISTRY OF BACTERIAL LUMINESCENCE 



KCF (Long-Chain Aldehydes) 



We had also noted an increased luminescence when a boiled bac- 

 terial extract was added to a system containing excess DPNHo and 

 FMN. (The effect of this factor is shown in Fig. 5.) However, we 

 were never able to separate this material from the heat precipitable 



COMCM (molesilO"^) 

 12 20 



28 



36 



MOLARITY « lO'' 



Fig. 5. Effect of aldehyde concentration on A. fisclieri extract luminescence. 

 0.1 ml of a 2% aqueous extract of A. fischeri was mixed with 1.5 ml of 

 0.1 M phosphate buffer, pH 7, plus 1000 ^g of DPNH= plus 4 ixg of FMN, 

 and light intensity was determined. Palmitic aldehyde was then added in 

 concentration indicated and light intensity was measured immediately after 

 each addition. 



fractions, although a variety of procedures was employed. Since it 

 seemed possible that some nonspecific effect of the boiled extracts 

 might be involved, we used another source of crude protein, in this 

 case kidney cortex powders, and obtained a large increase in lumines- 

 cence both from the residue and from the supernatant of this boiled 

 tissue powder (Cormier and Strehler, 1953). We called this com- 

 ponent the kidney cortex factor or KCF. 



A series of attempts were then made to purify this component by 

 various chemical and physical methods (Strehler and Cormier, 1954). 



