The Enzymes 0/ B. coli communis. 



In Table IV, these results are put together in order from left to right of 

 decreasing values for CO2 + formic acid. For the moment, we wish to direct 

 attention merely to those changes which have resulted from the introduction 

 of air during the fermentation ; changes due to other factors we will discuss 

 later. 



Table IV, — Products of the Decomposition of Glucose by B. coli communis 

 Expressed as Percentages of Glucose Consumed. Experiments arranged 

 from left to right in order of decreasing values of (CO2 + Formic Acid). 



Products. 



C. 



A. 



F. 



E. 





D. 



H. 



G-. 









■69 







•23 



0-41 



-49 







■13 







■23 







•18 



0-31 





25 



■83 



34 



■22 



■ 17 -28, 



16 19 



15 



■90 



14 



•74 



13 



•12 



6^55 





13 



•22 



1 



•25 



11 -01 



10 -74 



8 



•48 



4 



•01 



5 



■57 



7^02 





11 



■95 



8 



•91 



19 •SO 



21 11 



17 



■57 



43 



■39 



11 



•49 



16 -74 





19 



■52 



10 



•68 



20 -33 



23 16 



37 



•57 



11 



69 



30 



■23 



25 -24 





5 



•61 



3 



•94 



11 -49 



11 •87 



4 



•73 



5 



•64 



16 



•30 



18^23 





15 



■36 



22 



•45 



10 ^30 



9^06 



10 



•17 



14 



•22 



10 



•17 



10 ^41 



Total 



92 



•18 



81 



■68 



90 ^32 



92 ^62 



94 



■45 



93 



•92 



87 



•06 



84^50 



By arranging the products in the order as seen in Table IV, the first thing- 

 that is apparent is that all the anaerobic experiments fall on the left, and 

 all the aerobic experiments on the right of the middle line, so that we may 

 say that the most characteristic effect of aeration during fermentation is a 

 diminution in formic acid and the gaseous products, CO2 and II2, which for 

 many reasons we have been led to consider are derived from formic acid. 

 Corresponding with this diminution in the products containing one carbon 

 atom there is an increase either of a product with three C atoms (lactic 

 acid) or of two C atoms or a multiple of two (acetic acid, succinic acid). 

 The variations in the products are made clearer by representing the results- 

 pictorially as in fig. 1b. 



The following points may be noted with regard to fig. iB : — 



(1) The experiments have been arranged in order of decreasing values 

 of CO2 + formic acid, and no consideration has been taken as to the conditions 

 under which the various experiments were carried out. ISTevertheless, it 

 will be seen that all the anaerobic fermentations become grouped on the 

 left and all the aerobic experiments on the right of the figure. 



(2) The curve representing alcohol shows very little fluctuation in spite 

 of the great changes in acetic acid, and clearly aeration has but little effect 

 on the alcohol production, though it markedly increases the production of 

 acetic acid. 



t 



