THE CULTIVATION OF RUMEN OLIGOTRICH PROTOZOA

III. WHITE CLOVER FACTORS WHICH STIMULATE THE GROWTH OF ENTODINIA

Abstract

In an attempt to cultivate entodinia in a chemically defined medium, the nutritional requirement was studied by replacing the fractions of white clover with known substances. Nutrients, including the fractions of white clover, were given to the protozoa in a particulate form to facilitate the uptake of foods.
It was found that the lipid fraction was essential and that the water-soluble fraction was stimulatory for protozoal growth in a medium ontaining casein, proteose-peptone, and amylopectin. The water-soluble fraction was replaceable by soluble starch, glucose, ribonucleic acid, vitamins, and minerals. The lipid fraction was further fractionated systematically, and the results showed that the essential factors were contained in the digitonin- precipitated fraction. Three sterols, i.e., β-sitosterol, stigmasterol, and campesterol, were identified in this fraction. The requirement for white clover lipids by entodinia was completely satisfied by these sterols. Cholesterol was also effective, but ergosterol, lanosterol, and squalene had no effect.
Entodinia were successfully grown for more than 100 days in the medium which consisted of casein, proteose-peptone, amylopectin, soluble starch, glucose, ribonucleic acid, vitamins, minerals, and β-sitosterol.