244 BIOCHEMISTRY OF BACTERIAL LUMINESCENCE 



Harvey, E. N. 1929. A preliminary study of the reducing intensity of lumi- 

 nous bacteria. /. Gen. Physiol., 13, 16-20. 



Strehler, B. L., E. N. Harvey, J. J. Chang, and M. J. Cormier. 1954. The 

 luminescent oxidation of reduced riboflavin or reduced riboflavin phos- 

 phate in the bacterial luciferin-luciferase reaction. Proc. Natl. Acad. Sci. 

 U. S., 40, 10-12. 



Dr. Johnson: The role of peroxide in luminescent reactions is an 

 interesting problem. A theory is given in the book (Johnson, Eyring, 

 and Polissar, 1954) that would account for the luminescence of lu- 

 minol, with destruction of H2O2 but without destruction of the luminol, 

 the peroxide acting to induce a quinone type of electronic structure 

 which then radiates on returning to the freely resonating structure of 

 the substituted or unsubstituted ring. In arriving at this theory, how- 

 ever, it was necessary to assume that four molecules of H2O0 are 

 decomposed, in the reactions leading to light emission, in order to 

 account for the energy of the emitted light. In the scheme of reactions 

 presented by Dr. Strehler, the decomposition of only two molecules 

 of H2O2 is assumed, and the free energy made available thereby is 

 considerably short of the free energy needed for the observed light 

 emission. To this extent, the hypothesis, as it stands, does not appear 

 to be thermodynamically sound. The activation energy for the change 

 between normal and activated states cannot be added to the free 

 energy difFerence between the initial and final states to increase by 

 much the available free energy of reaction. 



Dr. Eyring: One restriction that thermodynamics places on any 

 mechanism is that one cannot get more free energy in the form of 

 quanta than is used up in the reactions. Thus, 



riiAF > n-Jiv (1) 



Here ni is the total number of molecules reacting and aF is the free 

 energy used up per individual process; 712 is the number of quanta 

 emitted and hv is the free energy of a quantum. The absolute maxi- 

 mum efficiency is thus 



* = ^' = t^ (2) 



rii hv 



Now such an efficiency can be approached if you use the reaction 

 to do work reversibly storing it in a battery and then use the battery 

 in an efficient fluorescent lamp. In principle this can also be realized 



