FURTHER EXPERIMENTS ON CELLULOSE DIGESTION BY THE PROTOZOA IN THE RUMEN OF CATTLE

Abstract

Diplodinium maggii, D. multivesciculatum, D. denticulatum, and Entodinium caudatum can be grown in flask cultures using as substrates grass, cellulose, and ground wheat, either singly or in combination, depending on the species being cultured. Clone cultures of D. denticulatum and E. caudatum show wide variations in the morph. of individuals in the clone. A rapid synthesis of food reserves from cellulose has been demonstrated in D. maggii. Cultural studies and expts. on cellulose digestion by extracts of the protozoa show that the 3 spp. of Diplodinium digest cellulose but E. caudatum does not. Microscopic observations indicate that all spp. of Diplodinium digest cellulose, whereas Entodinium, Isotricha, Dasytricha, and Butschlia do not. Thus, Diplodinium is the only one of these Protozoa which may be considered a symbiont.