THE CULTURE OF EUDIPLODINIUM NEGLECTUM, WITH EXPERIMENTS ON THE DIGESTION OF CELLULOSE

Abstract

A successful method for culturing this cattle ciliate is de''scr. The medium contains inorganic salts plus finely divided dried grass and cellulose. The osmotic pressure must be suitable and O2 must be excluded. The protozoa are obligate anaerobes. The organisms have been carried for 22 months on this medium. Enzyme extracts showing cel-lulase activity have been prepared from the protozoa. Appropriate controls show that the cellulase activity is not due to bacteria. The opt. reaction for action of the cellulase is about pH 5, a reaction similar to that in the endoplasmic sack of the protozoa. Glucose is the end product of the cellulose digestion and cellobiose is probably an intermediate product since cellobiase is present. Because of its cellulose-digesting capacity, E. neglectum is helpful to the host and the relationship between the 2 is one of symbiosis. Estimates indicate that about 1/5 of the protein requirements of the ruminant is supplied in the form of protozoa.