Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



One of the interesting symbiotic relationships in nature is that existing between the ruminants and their microbial population. This arrangement has solved for them the problem of existing on an herbivorous diet. Most mammals can derive little benefit from the potentially available energy in plant materials, which is locked in the complex, insoluble polysaccharide, cellulose. Cellulase is not a mammalian enzyme, but it is part of the chemical machinery of a number of bacteria, some species of which reside in the rumen. Many different organisms are present and their biochemical activities have not as yet been completely delineated. All of the organisms have not as yet been identified, nor their relative numbers assessed under different conditions. It is known, however, that the cellulose and other carbohydrates taken in are fermented with the eventual formation of simple fatty acids and gases. These fatty acids are absorbed through the rumen wall, circulate to the various tissues, and are there oxidized. The tissues of ruminants are enzymatically better equipped for the oxidation of fatty acids than are those of non-ruminants. Another function of the rumen organisms is to provide nitrogenous compounds and vitamins for their host. Their fate is eventually to be destroyed by proteases as they pass out of the rumen as digestion proceeds. For such a reason, ruminants can thrive on rations consisting of hay and simple nitrogenous compounds such as urea or ammonia. Investigations of the biochemical activity of the rumen have been carried out with the use of mixed, washed cell suspensions, which is a valid approach to the study of the overall physiology of this organ. An extensive study of the individual organism has not yet been made. This study has as its purpose the investigation of a rumen bacterium, with the hope of learning its physiological characteristics, some of its nutritional requirements, and placing it, if possible, in its taxonomic niche.

Library of Congress Subject Headings

Bacteriology, Agricultural
Rumen -- Microbiology


Includes bibliographical references



Number of Pages



South Dakota State University