46 PHYSIOLOGY OF BACTERIA 



C3H502(K2P04) + H2O = C3H6O3 + HK2PO4 



Glyceric aldehyde 



The glyceric aldehyde, by activation of a central 

 H-atom which then goes to the end-carbon, is changed to 

 methyl glyoxal. This process is an oxido-reduction, just 

 as the splitting of the sugar molecule into glyceric 

 aldehyde mentioned above must also be considered as a 

 process of this type. 



CH2OHCHOHCHO -> CH20H-CH0HC— OH -> 



Glyceric aldehyde Hydrate form \ 



CH2-CH0H-C + H2O -> 



H /H ^H 



CH2-C0H-C -^ CH3-C0H-C -> 



/OH /H /H 



CH3-C • C— OH -> CH3-C0-C— OH 

 ^OH "^OH "^OH 



Methyl glyoxal hydrate 



Up to this step, to the formation of methyl glyoxal, 

 all glucose fermentations seem to be alike. The next 

 steps decide about the different types, and methyl 

 glyoxal can be decomposed in a number of different ways. 

 But the number of possibilities is limited, and Kluyver 

 and Donker show that a few main types of oxido- 

 reductions of methyl glyoxal and its derivatives can 

 account for most of the well known fermentations. 

 The same reactions are used by different organisms in 



