GROWTH 233 



Cells per c.c. 



Unbuffered broth 60,000,000 



Buffered broth 480,000,000 



Broth with pH held constant 1 ,000 ,000 ,000 



Milk 1,000,000,000 



Milk with pH held constant 3,600,000,000 



Milk, aerated and pH held constant 5,200,000,000 



If the inhibiting product is removed, growth will 

 continue until another product of the cells inhibits 

 growth. In the case of lactic acid bacteria, the growth- 

 inhibiting compound after removal of the hydrogen 

 ions might be thought to be undissociated lactate which 

 was found to be the cause of cessation of fermentation 

 (p. 145). But the experiments of Rogers and Whittier 

 show no influence of lactates upon growth. 



With yeast in malt wort, alcohol is not the limiting 

 factor of the final amount of yeast, according to A. J. 

 Brown (1905). He found that it required very high 

 amounts of alcohol to decrease the final crop, as may be 

 seen from Table 63. 



Table 63. — Average Number op Yeast Cells per C.c. in Wort 

 WITH Increasing Amounts of Alcohol 



The added amounts of alcohol do not represent the 

 total alcohol concentration because some more is formed 



