218 



BIOCHEMISTRY OF BACTERIAL LUMINESCENCE 



thirtieth as great on a weight basis as KCF. Finally, KCF was iden- 

 tified as the Ci6 (palmitic) aldehyde by elementary analysis, mixed 

 melting points of the derivative, and molecular weight determination. 

 All aliphatic aldehydes from C7 to Cie are active although the lower 

 homologs are relatively less efiFective. See Table I. 



General Properties of System 



Color of Light 



The spectral distribution of the luminescence of extracts and intact 

 bacteria were compared and found, within experimental error, to be 

 identical (see Fig. 6). This finding along with the other parallelisms 

 between in vivo and in vitro luminescence makes it likely that the 



500- 



< 

 q: 



o 



3 

 o 

 o 



300- 



I 

 o 



100- 



400 



700 



500 600 



WAVE LENGTH ( m^ ) 



Fig. 6. Emission spectra of intact A. fischeri and extracts obtained from A. 

 fischeri. 0.5-mm slit width Farrand quartz monochromator. # Emission of 

 bacteria. O Emission of extracts. A Extract emission normalized to bac- 

 terial emission at 490 ni/i. The gross reading was not corrected for changes 

 in dispersion of monochromator or sensitivity of photomultiplier. 



