IONIC EFFECTS UPON BIOLUMINESCENCE IN 

 GONYAULAX EXTRACTS 



J. Woodland Hastings and Vernon C. Bode^ 



Division of Biochemistry, Department of Chemistry and Chemical Engineering, 



University of Illinois, Urbana, Illinois 



The beautiful and sometimes spectacular "phosphorescence" of 

 the seas is due in many, though not all instances, to the biolumines- 

 cence of unicellular organisms, the dinoflagellates (3). This same 

 group of organisms is also responsible for the well-known phenomenon 

 of red tides. The sea water at such times appears blood-red in 

 color because of an excessively large dinoflagellate population, and 

 sometimes only one species is involved. The conditions which give 

 rise to such an excessive growth are presumably nutritional, but they 

 are not yet fully understood (12) . 



B. M. Sweeney has isolated and cultured in the laboratory a num- 

 ber of marine dinoflagellates. One of these, Gonyaulax polyedra, 

 was found to be brilliantly limiinescent in culture (6) . Light emis- 

 sion in cell-free extracts from these organisms was found to require, 

 in addition to oxygen, at least three factors: a heat-labile enzyme, 

 a factor in the boiled extract, and salt in a high concentration (5) . 

 The mechanism of the reaction appeared similar in certain respects 

 to the luciferin-luciferase systems described for other organisms (2, 3, 

 8, 10, 13, 15), but it was found that there was no cross-reaction be- 

 tween Gonyaulax luciferin or luciferase and those of the firefly, 

 bacteria, or Cypridina. We can report, however, that Gonyaulax 

 polyedra luciferin and luciferase preparations will cross-react with 

 preparations from another species, Gonyaulax monilata. 



Gonyaulax is an obligate photoauxotroph, and is grown in large 

 quantities in Fernbach flasks, utilizing fluorescent bulbs as the light 

 source. Either of two cidture media are used: a supplemented sea- 

 water medium modified from an earlier one (14), or an artificial 

 sea-water medium, modified from the ASP medium of Provasoli, 



' Predoctoral Fellow, National Cancer Institute, Public Health Service. 



294 



