184 GENERAL MICROBIOLOGY 



This cannot take place, however, if above 10 to 12% 

 acetic acid is present, as this amount is antiseptic to the 

 vinegar bacteria. (See pp. 450-451, Marshall.) 



E. Organic acid decomposition, by acidophile organisms 

 (organisms of the Oidium and Mycoderma type). 



lactic acid +oxygen +oxidizing enzyme = carbon dioxide + water 

 CH 3 CHOHCOOH + 6O + lactacidase = 3CO 2 +3H 2 O. 



The destruction by oxidation of acetic acid by the acetic 

 bacteria is given under D above. 



Nearly all organic acids are decomposed in a similar 

 manner, by total combustion. 



F. Reactions of reductases. 



hydrogen peroxide oxygen + reducing enzyme = water +oxygen. 

 H 2 O 2 O + catalase = H 2 O + O. 



methylen blue +hydrogen + methylen blue = leuco-basa of 



reductase methylen blue. 



C 6 H 3 N=(CH 3 ) 2 C 6 H 3 N=(CH 3 ) 2 



N As 



reductase J 



C 6 H 3 =N=(CH 3 ) 2 C 6 H 3 N=(CH 3 ) 2 



G. Lactic acid fermentation, produced in milk by 

 Bact. lactis acidi. 



lactose + water -fhydroly tic enzyme = d-dextrose-fd-galactose. 

 Ci 2 H 22 Ou + H 2 + ' lactose = C 6 H 12 O 6 +C 6 H 12 O 6 . 



dextrose 1 +enzyme producing intra- = lactic acid. 

 galactose J molecular change 



c acid bacteria zyraa*e = 4CH 3 CHOHCOOH. 



Bact. lactis acidi will ferment a nutrient solution con- 

 taining only a simple sugar, e.g., dextrose, the reaction then 

 being according to the second equation. 



