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Exercise 22. Cellulose Fermentation 
MATERIALS: 
2 20 c.m. test tubes 
100 c.c. of Omeliansky’s solution. 
A suspension of cow manure 
4 strips of filter paper 
25 c.c. graduate 
Vaseline 
Cellulose is the main constituent of the woody fiber of all plant tissue. In 
soils, marshes, the bottoms of ponds and rivers, manure piles, and compost 
heaps, cellulose is constantly undergoing decomposition. The purest forms of 
cellulose are quickly attacked by bacteria, and the progress of the decomposi¬ 
tion of a substance like filter paper is easily observed. 
Ammonium sulphate (NH 4 ) 8 S0 4 )_ 
Magnesium sulphate (MgS0 4 )_ 
Di-basic potassium phosphate (K 8 HP0 4 )_ 
Calcium carbonate (CaC0 3 )_ 
Sodium chloride (NaCl)_ 
Water_ 
0.5 grams 
0.5 “ 
1.0 “ 
5.0 “ 
a trace 
1000.0 “ 
This solution is called Omeliansky’s solution. 
1. Fill two large test tubes one-third full of the culture solution on the desk. 
See that the solution is well agitated before taking any of it, as the insoluble 
substances settle out. 
2. Add about 5 cc. of a suspension of cow manure to each tube. 
3. Immerse two strips of filter paper in a vertical position. 
4. Cover the surface of the liquid with about one-half inch of melted vase¬ 
line to exclude air. 
5. Sterilize one of the tubes to prevent bacterial growth. Observe the 
precautions of Exercise 7, when labeling the tubes. 
6. Incubate both tubes at 37° C. 
7. Compare the tubes after changes in the paper are apparent. 
8. Draw and describe the appearance of the paper. 
9. (a) What is the odor like in the tubes? 
( b ) What is the origin of the odor? 
(c) How has the color of the paper and deposits changed? 
( d) Chemically what kind of a substance is filter paper and what 
does it yield on hydrolysis? 
(e) What are the by-products of cellulose fermentation? What 
service do they render in the soil? 
(0 Why is an abundance of cellulose necessary in the heating of 
manure? 
( g) What kinds of manure heat? 
(/?) Give three additional instances where cellulose fermentation 
is important in farm practice? 
