SOME ASPECTS OF NITRATE REDUCTION 



40 

 minutes 



20 40 60 80 



minutes 



Fig. I. Hydrogen consumption with 

 nitrate as acceptor. Cwrw /l, bacteria 

 grown on Grohmann medium with 

 nitrate. Curve B, bacteria grown on 

 peptone agar with nitrate both in a 

 hydrogen atmosphere. 



Fig. 2. Hydrogen consumption with 

 either 2 or nitrate as acceptor by 

 bacteria grown on Grohmann me- 

 dium with nitrate in a hydrogen at- 

 mosphere. Curve A, gas change in 

 50% H 2 , 10% 2 and 40% N 2 in the 

 absence of nitrate. Curve B, gas 

 change in hydrogen with nitrate. 

 Curves A' and B', give the net hydro- 

 gen consumption in the two cases. 



Fig. 3. Hydrogen consumption with 

 either 2 or nitrate as acceptor by 

 bacteria grown on Grohmann me- 

 dium without nitrate in an atmos- 

 phere containing H 2 and 2 . Curve 

 A, gas change in 50% H 2 , 10% 2 

 and 40% N, in the absence of 

 nitrate. Curve B, gas change in hydro- 

 gen with nitrate. 



499 



