PHOTOSYNTHETIC PHOSPHORYLATION AND THE ENERGY CONVERSION 'PROCESS 375 



TABLE VII 



Photoproduction of Hydrogen from Succinate by Chromatium 

 (Ogata, Nozaki, and Arnon [91]) 



Treatment 



1. Complete 



2. Complete, KOH omitted 



3. Complete, dark 



4. Complete, succinate omitted 



1 . Complete 



2. Complete, succinate omitted 



3. Complete, plus palladium asbestos 



4. Complete, plus carbon monoxide 



ftmoles H; 

 evolved 



8-6 



The complete system contained, in a final volume of 3-0 ml., 100 mg. wet 

 cells that were suspended in a modified nutrient solution with nitrogen omitted, 

 and the following in micromoles ; tris buffer, pH 7-2, 80; AlgCl,, 5 ; succinate, 20. 

 o- I ml. of 20",, KOH was present in the centre well. The reaction was carried out 

 for 2 hr. at 30 in argon. Illumination 35 000 Lux. 



thiosulphate was also inhibited by molecular nitrogen and ammonium ions. 

 The results are shown in Fig. 19. 



The photoproduction of hydrogen was dependent on the concentration 

 of thiosulphate and was abolished by heating the cells (Fig. 20). Growing 

 Chromatium cells were found, by analysis to have oxidized in 4 days 27 

 millimoles of added thiosulphate into 54 millimoles of sulphate. During 



30 60 90 120 150 



minutes 



Fig. 17. Photoproduction of hydrogen gas from succinate by Chromatium 

 cells. Experimental conditions as described in Table \ll (Ogata, Xozaki, and 

 Arnon [91]). 



