1911.] Acetylmethylcarbinol and 2.3-Butylene Glycol. 



493 



produce both substances from glucose, mannitol, and fructose (6, 7, 8) ; hence, 

 in the first place, the action of these organisms was studied, and similar 

 experiments were later carried out with B. coli communis, but with negative 

 results. 



It was of especial interest to discover whether these substances could be 

 produced from carbon compounds less complex than the hexoses, and a 

 variety of simpler substances containing fewer carbon atoms were therefore 

 tried, e.g., glycerol, ethylene glycol, malic acid, etc. 



The formation of acetylmethylcarbinol or butylene glycol from substances 

 containing three or fewer carbon atoms would necessarily involve a carbon 

 synthesis which would be of considerable theoretical interest. An instance 

 of this kind, the production of butyric acid and butyl alcohol from lactic acid 

 and from glycerol in the butyric fermentation, ha.s long been known (9, 10). 

 To explain this, it has been supposed that acetaldehyde is first formed and 

 then serves as the source of the butyl alcohol and butyric acid. The 

 aldehyde may be supposed to undergo an aldol condensation followed by 

 reduction, with or without subsequent oxidation : 



2CH 3 -CHO = CH 8 -CH(OH)-CH 2 -CHO. 

 CH 3 -CH(OH)-CH 2 -CHO + 4H = CH 3 -CH 2 -CH 2 -CH 2 -OH + H 2 0. 



It seems possible that the production of acetylmethylcarbinol and 

 butylene glycol may be due to a somewhat similar course of events, which 

 may be represented as follows, although these reactions have not, hitherto,, 

 been observed in the laboratory : — 



2CH 3 -CHO + 2H = CH 3 -CH(OH)-CH(OH)-CH 3 . 

 2CH 3 -CHO = CH 3 -CO-CH(OH)-CH 3 . 



Experiments to test this hypothesis were made, with the result that the 

 production of the glycol by bacterial action from acetaldehyde was con- 

 clusively established, although the mechanism of this production has not yet 

 been ascertained. 



It by no means necessarily follows, however, that in the fermentation of 

 glucose the butylene glycol is actually produced from preformed 

 acetaldehyde. 



1. Experimental Methods. 

 As a general rule the culture medium consisted of 1 per cent. Witte's 

 peptone water containing 5 per cent, of the substance under investigation. 

 Sufficient chalk was added to neutralise any acid formed during fermentation, 

 and after inoculation the culture was grown for three weeks at 37° C. under 

 anaerobic conditions, the flask being fitted with a mercury trap to allow the 

 escape of any gases. 



