ALKALI-FORMING BACTERIA FOUND IN MILK. 25 



Table 11. — Summary of the fermentation of the organic-acul salts. ■ 



Acid. 



Pyruvic . . 

 Citric 



Malic 



Lactic 



Succinic . . 



Acetic 



Propionic 

 Butyric... 

 Valeric . . . 

 Caproic. . . 

 Mucic . . . . 



Glyceric . . 

 Tartaric . . 



Oxalic 



Malonic. . , 

 Glycolic . . 

 Formic . . . 



Benzoic. 

 Salicylic. 



Chemical structure. 



CH3COCOOH.... 

 fCHs — COOHl 



■^coH-coony 



[CH2 — coohJ 



rCH— (OH) COOH\ 



\CH2-COOH / 

 CH3 



CHOH 



COOH 



/CH2— COOH\ 

 \CH2— COOH/- 



CHsCOOH- 



CH3CH2COOH 



CH3 CH2 CH2 COOH 



CH3 CH2 CH2 CH2 COOH 



CH3 CH2 CH2 CH2 CH2 COOH 



COOH (CHOH) "(CHOH) (CHOH) 

 (CHOH) COOH. 



CH2OH (CHOH) COOH 



COOH (CHOH) (CHOH) COOH 



/COOH\ 



\COOH/ 



PTT „^^COOH\ 



L±i2 \^cOOH/ 



/CHsOHl 



1 COOH/ •■ 



H-C=^ ^\ 



^ ^\OB.f 



^COOH 



COOH 



TOH 



Number 



of 

 cultures 

 ferment- 

 ing. 



Remarks. 



Ketone connecting a carboxyl 

 and a methyl radical. 



•Secondary or tertiary alcohol 

 radical linked to a carboxyl 

 and to a.methyl radical. 



No alcohol radical. Methyl 

 Unked to a carboxyl radical. 



Alcohol radical lioked to a car- 

 boxyl and to another alcohol 

 radical. 



Two carboxyls linked together. 



Two carboxyls linked with 

 methyl radical. 

 iPrimary alcohol linked wth a 

 / carboxyl. 



1 Aldehyd radical linked to hy- 

 / droxyl. 



Benzol ring. 



Total number of cultures, 



Some of tlie bacteria were able to obtain tbeir carbon from benzoic 

 and salicylic acids, in which case it was apparently necessary for the 

 bacteria to split the benzol ring. If they could obtain their carbon 

 without splitting the benzol ring they would have to take it from the 

 COOH group, and if it was possible in this case, it would be expected 

 that they could also obtain carbon from the COOH group of oxalic 

 acid. The sodium salt of benzoic acid was fermented by more cul- 

 tures than that of salicylic acid, as is shown by the fact that 16 cul- 

 tures fermented benzoic and only 12 salicylic. The stronger anti- 

 septic property of salicylic acid, which possibly is due to the presence 

 of the hy droxyl group, may make it difficult for some of the bacteria 

 to grow in the presence of the acid salts. 



