415 



The Chemical Action on Glucose of a Variety of Bacillus coli 

 communis (Escherich), obtained by Cultivation in Presence of 

 a Chloroacetate. (Preliminary Notice.) 



By A. Harden, F.R.S., and W. J. Penfold. 



(Received May 18 —Read June 20, 1912.) 



(Biochemical Department of the Lister Institute.) 



Penfold has shown (1) that when Bacillus coli communis (Escherich) is plated 

 out on nutrient agar containing 05 per cent, sodium chloroacetate, a large- 

 number of small colonies and a few large ones are produced. The cultures 

 obtained from some, but not all, of the large colonies were found to have lost 

 the power of producing gas from glucose when grown in glucose peptone water 

 in a test tube provided with a Durham gas tube. Under the same conditions 

 these same organisms still produced gas from mannitol, but in diminished 

 proportion. Several other intestinal organisms have since been found by 

 Harden to behave in a similar manner on chloroacetate agar, whereas 

 B. lactis aerogenes, which produces a different type of decomposition of 

 sugar, has hitherto proved resistant to this method of selection. In order 

 to ascertain what other modification the chemical action of the original 

 strain had undergone, comparative quantitative experiments were carried 

 out with the original and the selected organisms. 



Product. 



Percentage of sugar 

 used. 



Carbon atoms per molecule 

 of glucose. 



Harden's theory 

 for B. coli 



Carbon atoms. 



Normal 



Selected 

 B. coli. 



Normal 

 B. coli. 



Selected 

 B. coli. 





17 "22 

 20-60 



2-55 

 17 -30 

 40-o"0 



4-80 



5-5 

 10-02 

 3-53 

 2-00 

 77 -6 

 None 



1 -35 

 1 -24 



2-43 

 0-29 



0-43 

 0-60 



4-66 



1 

 1 



1 

 3 





93 -07 



98 -65 



6-12 



5-91 



6 



H (as gas) c.c. per grm. 



of sugar 

 H as gas + H equivalent 



of formic acid 



80 -6 

 92 -9 



12 -6 

 29 -8 









VOL. LXXXV. — B. 



