240 



BV + DOC 



180 



120 



O BV 



MINUTES 



Fig. 1. Effect of lipid-dispersing agents on hydrogenase activity oiR. rubrinii 

 particles. 



Washed R. nibriDU cells, grown in a malate + glutamate medium, were sus- 

 pended in 0.05 M potassium phosphate buffer pH 7.1 and sonicated (Raytheon 10 

 KG) under hydrogen for 3 minutes. Pigmented particles werecoUected bycentri- 

 fugation at 144,000 x g for 60 minutes and resuspended in 0.05 M phosphate 

 buffer pH 7.6. The Warburg vessels contained, in a final fluid volume of 2.0 ml: 

 particles equivalent to 0.75 mg bacteriochlorophyll; potassium phosphate pH 

 7.6, 275/ymoles; benzyl viologen (BV), 100 ^moles (added at zero time); where 

 indicated, 10 mg sodium deoxycholate (DOC) or 10 mg sodium lauryl sulfate (LS). 

 Gas phase, H2 (KOH in center well); temperature 30°C. 



