ACTION OF THE ENZYME CATALASE 191 



4. Give all results in full and draw any conclusions 

 permissible. What practical applications may be made of 

 the above? 



REFERENCES 



MARSHALL, C. E.: Microbiology, pp. 135, 142-143. 



LAFAR, F.: Technical Mycology, Vol. II, Part II, pp. 558-560. 



KRUSE, W. : Allegemeine Mikrobiologie, pp. 652-655. 



EXERCISE 16. TO SHOW THE ACTION OF THE 

 ENZYME CATALASE 



Apparatus. Four fermentation tubes of nutrient broth 

 (sterile) ; hydrogen peroxide (full strength) . 



Cultures. B. coli; B. subtilis; B. mycoides; Bad. 

 lactis acidi. 



Method. 1. Inoculate the fermentation tubes. 



2. After growth is well started, add 1 c.c. of hydrogen 

 peroxide to each tube and mix well. 



3. After the tubes have stood for half an hour measure 

 the gas formed. Compare your results with those of other 

 students. 



Note. If the bottle of H 2 O 2 stands uncorked or in a warm place 

 it decomposes very rapidly and the gas formed in the fermentation 

 tubes will be much less than from a full strength solution. 



4. What is the strength of commercial hydrogen 

 peroxide? 



Where else is catalase found? What is the type of action 

 supposedly taking place? Write chemical equation showing 

 the general reaction. 



Have you ever observed the action of catalase produced 

 in animal tissues? What is the difference between catalase 

 and peroxidase? 



5. State the results of your experiment in full and draw 

 any conclusions permissible. Point out any practical 

 applications that may be made. 



