ALKALI-FORMIISTG BACTERIA FOUISTD IN MILK. 



29 



pounds. The urea was sterilized through a Berkefeld filter, so there 

 was no ammonium carbonate present as would have been the case 

 if the ordinary method of steam sterilization had been employed. 

 Ammonia was an end product from all three of these test substances, 

 and with urea the only alkali end product possible. Reference to 

 Table 10 shows that 13 of the cultures fermented hippuric acid, 8 

 uric acid, and 41 urea. In addition to the 68 cultures of alkah- 

 forming. bacteria isolated from dairy products, the fermentation of 

 the organic-acid salts was tried with 55 known cultures, namely, 37 

 strains of dysentery, 6 of proteus, 6 of typhoid, 3 of paratyphoid, 

 and r each of B. abortus, B. hronchisepticus, B. fsecalis alkaligenes, 

 and B. enteriditis. The results of the fermentation of the citric and 

 lactic salts and Htmus-milk reaction are given in Table 13. It is 

 evident from the results that all the cultures fermented the citrate 

 and a large number of them the lactate. Many of the cultures gave 

 characteristic milk reaction of the alkali-forming group of bacteria. 



Table 13.- 



- Fermentation of the sodium salt of citric and lactic acid together with the 

 milk reactions of known cultures. 



Culture. 



Litmus-milk 



reaction, 7 days 



at 30° C. 



Ph value, 3 

 days at 37° C. 



Culture. 



Litmus-milk 



reaction, 7 days 



at 30° C. 



Ph value, 3 

 days at 37° C. 





Citric. 



Lactic. 



Citric. 



Lactic. 







6.8 



7.2 



Dysentery- 

 Continued. 

 8 



No change 



Slight acid 



No change 



... do 



7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 8.6 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 















8.4 

 8.8 

 8.3 

 8.3 

 8.4 

 8.3 



7.5 

 7.4 

 8.4 

 7.3 

 7.4 

 7.0 



7.4 

 8.5 

 8.5 

 8.5 

 8.4 

 7.3 



7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 

 7.4 



6.9 

 8.6 

 7.2 

 7.0 

 7.3 

 7.0 



7.3 

 7.3 

 7.5 

 7.3 

 7.3 

 7.0 



7.0 

 7.3 



7.7 

 7.3 

 7.5 

 7.3 



7.3 



• 7.1 



7.3 



7.3 



7.4 

 7.4 

 7.0 



7.3 



ACL . . 



9 



7.1 



ACN 



ACU .... 



do 



10 



7.4 



do.. 



11.. 



7.1 



ACV 



do 



12 



do 



7.3 



ADE 



do.. 



13 



Coagulf ted, acid. 



Slightacid 



do .. 



7.4 



ADG 



do 



14 



7.3 



Typhoid: 



607 



Ooagiilated,aeid. 

 No change 



15 



7.4 



16 



Alkaline 



No change 



do...^ 



7.5 



608 



17 



7.4 



Rowd 



IS 



7.1 



M. T. S Slightacid 



20 



do... 



7.3 



21 



do 



7.2 



Hop 22 



Parat3'phoid: 

 16 



do.. . 



22 



Coagulated, acd. 

 Slight alkaline.. 



Slightacid 



do 



7.8 





23 





No change 



Alkaline 



do... 



24 



7.0 



22 



25 



7.0 



323 



26 



do 



7.0 





do 



27 



No change 



do 



7.4 





do . . . 



28 



7.3 



B. hronchisepti- 

 cus. 



do 



29 



do 



7.3 



No change 



do 



30 



do 



7.4 



Dysentery: 



31 



do 



7.3 



32 



Slight acid 



No change 



do 



7.1 



2 



■33 



7.5 



3 



Slight acid 



No change 



Slightacid 



do 



34 



7.3 



4 



35 



do 



7.3 





36 



do 



7.3 



6 



37 



Slightacid 



No change 



7.0 



7 



No change 



38 



7.4 









The salts of organic acids not only serve as a source of carbon 

 for the alkali-forming bacteria and, therefore, are valuable test 

 substances, but their use need not be limited to the bacteria of 

 this group. In fact, it seems probable that they may have an 

 extensive application in the study of other groups of bacteria. 



