Factors Necessary for the Growth of Bacteroides Succinogenes in the Volatile Acid Fraction of Rumen Fluid

Studies on the kinds of bacteria present in the bovine rumen have shown that Bacteroides succinogenes is one of the more important cellulolytic agents therein Work on the growth requirements of this species has shown that rumen fluid contains a growth factor that was not detectable in several materials commonly used to grow nutritionally exacting bacteria or in extracts from alfalfa meal or bovine feces (6). This factor was found to be stable in rumen fluid that was autoclaved at pH 3 and pH 9 for 1 hour at 15 lb. pressure and in rumen fluid dried on a steam bath and reconstituted with distilled water. It was not replaced by known B vitamins, minerals, several purines and pyrimidines, oleic acid, acetic acid, Tween 80, or an acid or enzymatic hydrolyzate of casein, although some of these substances undoubtedly are also required. Hungate (16) concluded that the factors required for growth of this organism are