142 



PROVISION OF energy: fermentation 



It is now possible to outline the intermediate reactions 

 involved in the formation of all the fermentation products of 

 the coli-aerogenes group of organisms: 

 GLUCOSE 



Hexose-di-phosphate 



Dihydroxyacetonephosphote ^ Glyceroldehyde-phosphate 



<»< -glycerophosphate Phosphoglyceric acid 



ETHYL ALCOHOL Formic acid 



Hi CO2 



Phosphopyruvic acid 



I 



Pyruvic acid 



Formic acid 



ACETIC LACTIC SUCCINIC 

 ACID ACID ACID 



H; 



CO- 



ACETYLM ETHYL 

 CARBINOL 



n 



2.3. BUTYLENE 

 GLYCOL 



Acetone-butanol fermentation 



The fermentation of maize meal or molasses by CI. aceto- 

 hutylicum became of importance in the war of 1914-18 as it 

 was then the most satisfactory method of making acetone on 

 a commercial scale. Since that time the synthesis of acetone 

 by a cheaper chemical method has been worked out and the 

 fermentation method is no longer of such industrial importance. 

 A further product of the fermentation is butyl alcohol (butanol) 

 which is now required on a large scale as a paint and lacquer 

 solvent. As a result of the commercial value of the products, 

 the fermentation has received considerable attention which 

 has not, as yet, succeeded in unravelling all the intermediate 

 reactions. The research was hampered by the fact that, until 

 recently, it has not been possible to prepare washed suspensions 

 of the organism in an active state, but this difficulty has now 

 been largely overcome by the use of concentrated suspensions, 

 rather than washed suspensions, and a certain amount of 

 knowledge of the course of the fermentation has been obtained. 



