ROBERT L. STARKEY 



33^ 



compounds. The energy values for some of the autotrophic bacteria have been 

 calculated by Baas-Becking and Parks as free energy efficiency/ 



Reaction 



Author 



N03-+|0. = N03- 



-+H.O+2H+ Meyerhof* 



Meyerhoff 



S+i|0.+H,0 = H.SO,. 



WinogradskyJ 

 (Beggiatoa) 

 1 Waksman and Starkey§ 

 [ {Th. thiooxidans) 



6KN03-t-sS-|-2CaC03 = 3K.S04 



+ 2CaS04+2CO.+ 2N. 

 5Na.SA+8KN03+2NaHC03 = 6Na.SOj L' k IT 



Beijerinck|| 



+4K.SO4+4N.+ 2CO.+H.O 

 H,+|02 = H.O Ruhland** 



* Loc. cit. t Loc cit. % Loc. cil. § Loc. cit. 1 1 Loc. cii. f Loc. cil. ** Loc. cit. 



Free Energy 

 Efficiency 

 Percentage 



7-9 

 5-9 

 8.3 



8.3 



S-o 



9.0 

 26.4 



The mechanism of assimilation of carbon dioxide by autotrophic bacteria shows 

 some striking similarities to the photosynthetic reaction in higher plants. Klein and 

 Svolba' have distinguished between assimilation, respiration, and oxidation in 

 studies of two autotrophic bacteria, one an obligate and the other a facultative auto- 

 troph. It was observed that in the assimilation reaction carbon dioxide was reduced, 

 and that in the course of its use for the synthesis of organic compounds formaldehyde 

 was formed.- Respiration, or the disintegration of synthesized organic compounds, was 

 accompanied by the formation of acetaldehyde. The energy for these synthetic re- 

 actions was derived from the process of oxidation of the specific inorganic compound. 



' Loc. cit. 



^ Klein, G., and Svolba, F.: Ztschr. f. Botan., 19, 65-100. 1926; see also Loew, O.: Biochem. 

 Zlschr., 140, 324-25. 1923; Kluyver, A. L., and Donker, H. J. L.: Chemie d. Zelle u. Geivebe, 13, 134- 

 90. 1926. 



