OPT. . 1 r '77 1 .. // i:ri:dit\ amj i:\ virosmext 65 



and Kitahai-a [VXu) who eslablislicd that the lactic-acid 

 bacteria which produced racemic acid are also capable 

 of racemiziiig a ready-made active acid. This is per- 

 formed by a special enzyme, called by these authors race- 

 miase. Those species and strains of bacteria which, in 

 fermentation, form as a tinal product optically active lac- 

 tic acid cannot racemize a ready-made active acid, they 

 have no racemiase. The formation of racemiase is closely 

 dependent on the culture conditions. 



The results of the experiments of Katagiri and Kita- 

 hara (1937) are represented in Table 11. They show 

 clearly that, with various strains of Leuconostoc mesen- 

 teroides and Lactobacillus sake, a change of the condi- 

 tions of cultivation never brings about a change in the 

 type of the lactic acid formed ; a greater or lesser degree 

 of racemization of the substance produced accounts for 

 all the observed facts. 



c. I n f 1 u e n c e of T e m p e r a t u r e. Similar 

 results were reported also in investigations on the in- 



TABLE 11 



Inflxjence of the Sugar Fermented ox the Optical Foi:m of the 



Lactic Acid Produced in the Fermentation 



(Katagiri and Kitahara, 1937) 



(The letters 1, d and dl indicate the optical rotation.) 



Microorganism Glucose ' Fructose 



Mannose Galactose Arabinose Xylose 



