PASTEUR EFFECT 



53 



similar eflBciency. In the upper part are predominantly aerobic 

 types, e.g., kidney and liver and many plant cells with relatively 

 small fermentative capacity, and at the top of the scale is a strict 

 aerobe, azotobacter, with Qog of 2000 and no trace of fermentation. 



Table 1.— Effect of oxygen on glycolysis 



Organism or 

 tissue 



Qo, Qo^ QN=F 



Substrate 

 consumption 



Caloric 

 yield 



Refer- 



^ anaerobic . , anaerobic ence 

 rate* — — ratej 



aerobic 



aerobic 



Torula 



anaerobic . . . — 260 1.04 



aerobic ... .-180 18 — 0.31 



Embryonic heart 



anaerobic . . . — 28 0.11 



aerobic .... -13.6 — 0.018 



Pigeon brain 



anaerobic . . . — 28 0.11 



aerobic .... -16 — 0.022 



Fish retina (30° C.) 



anaerobic . . . — 29 0.12 



aerobic .... - 9.6 1 — 0.017 



3.4 



6.0 



5.0 



7.0 



* mg. glucose per mg. dry weight per hour. f calories per mg. dry weight per hour. 



On the anaerobic side, below the middle, are a variety of types 

 representing gradations down to exclusively anaerobic life. Here 

 fermentation is partly or wholly persistent in the presence of oxy- 

 gen, and respiration becomes a more or less residual function, 



BACTERIA 



The anaerobic type of life is most common among the bacteria, 

 but it occurs frequently in the animal kingdom, esoecially among 

 invertebrates. In all stages of phylogenetic development, life either 

 chooses or is forced to adapt to anaerobic conditions, and similar 

 metabolic arrangements correspond to similar environmental condi- 

 tions. Transition from alternative to exclusive anaerobiosis is well 

 illustrated by a tabulation of the metabohsm of the common yeasts 

 (Table 2), taken from Meyerhof s classical paper (6). 



The almost exclusively anaerobic cultured yeasts used in the 

 manufacture of alcoholic beverages presumably developed from the 



