CELLULOSE FERMENTATION. 63 



EXERCISE L. 



CELLULOSE FERMENTATION BY CULTURES OP DENITRIELERS. 



1. Make up the following solution: 



1,000 cc. tap water. 

 2.5 gms. KNOa. 

 0.5 gm. KjHPOj. 



2. Place in Brlenmeyer flask of 200 ce. capacity 2 gms. 

 of pure absorbent cotton; fill to the neck with the above 

 solution ; add a few cc. of ditch water. 



3. Incubate at 35° for 15-20 days. 



4. Test for the disappearance of nitrate reaction. 



5. Pour off liquid; wash, dry and weigh the cotton. 



6. Eecord changed appearance and loss in the weight of 

 the cotton. 



