272 LIGHT AND LIFE 



Inhibition of the fungal luminous system in vitro by such com- 

 poimds as cyanide, 8-hydroxyquinoline, and ortho-phenanthroline 

 suggests a metal requirement, and this matter is being investigated. 



In conclusion, residts so far confirm the fact that under certain 

 conditions it is possible to conduct in vitro light reactions of the 

 classical luciferin-luciferase type for the fungi. The hot water ex- 

 tract used in these reactions may represent oxyluciferin, and this 

 could be reduced — presumably Ijy reduced pyridine nucleotide — to 

 luciferin, the latter reacting with luciferase for emission of light. 

 The number of enzymes involved in this reaction sequence is un- 



TABLE 2 

 Inhikitors of Fungal Bioluminescence in vitro 



known. The results obtained on the secondary addition of bovine 

 plasma albumin suggest that there are at least two. This matter 

 should be resolved by further purification of the enzyme system. 

 Along the same line, there is no indication of a pyridine nucleotide 

 specificity, but the presence of a transhydrogenase is quite conceivable. 

 In several respects the mold system is not comparable with the bac- 

 terial system: (a) addition of reduced flavin mononucleotide does 

 not stimulate the fungal bioluminescent system; (b) long-chain alde- 

 hydes are not required; and (c) the emission maximum of the lumin- 

 ous mold in vivo is at 5.S0 ni/i while that of Photobacteriiim fischeri 

 is at approximately 480 ni/x. The excitation energy requirement for 

 the fungal l)i()luminesceiuc would Ix- approximately 55 kilocalories 

 per mole (piauta rather than ilic (iO kilocalories recjuired by the 

 luminous bacteria. 



