Some Observations on the Chemiluminescence of 



Algae* 



JOHN E. BRUGGER, University of Chicago (Fels Fund), 



Chicago, Illinois 



Our investigations of the chemiluminescence of algae were ini- 

 tiated several years ago. At that time Dr. Rosenberg and I were 

 looking for a phosphorescence of chlorophyll dissolved in rigid 

 glasses or adsorbed on a surface. In the course of this work the 

 chemiluminescence, previously reported by Strehler and Arnold, was 

 observed. It was decided to investigate this phenomenon in a manner 

 somewhat different from that employed by them. Instead of a flow 

 technique, we used a phosphoroscopic method. The results are in- 

 terestingly different in many respects. 



Algae were irradiated with repeated pulses of blue light. Be- 

 tween these flashes, the chemiluminescence was measured. The 

 time sequence was (in milliseconds): irradiate, 1.25; dark, 0.75; 

 measure, 1.25; dark, 0.75. The intensity of the luminescence 

 was determined with a 1P22 multiplier phototube, fitted with 

 a red filter. The photosignal was amplified and recorded (GR 

 DC amplifier and Esterline Angus recorder). At the present 

 time, a quantum counting technique is being used to meter the 

 photosignal. A 3-ml. sample of algae (density: 2 i^l. packed wet cells/ 

 ml. suspension) was placed in a cell having a sintered glass bottom 

 through which various gases could be passed — another variance from 

 the technique of Strehler and Arnold. Chlorella pyrenoidosa were 

 used in the work reported here. However, experiments with Scene- 

 desmus obliquus D3 have given similar results. Irradiation was also 

 undertaken with green, yellow and red light (with and without ad- 

 mixtures of blue light). Within the uncertainties introduced due to 

 hght leak and other experimental difhcuities, the results are quali- 

 tatively the same as those obtained with blue light. As Arnold and 



* This work was aided by a contract between the Office of Naval Research, 

 Department of the Navy, and the University of Chicago (Contract ONR 432- 

 (00)). 



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