Isolation and Identification of Compounds from Autolyzed Yeast, Alfalfa Meal, and Casein Hydrolysate with Cellulolytic Factor Activity for Rumen Microorganisms In Vitro

Abstract

The cellulolytic factor activity of autolyzed yeast, casein hydrolysate and alfalfa extract was isolated by Dowex-50 ion exchange resin treatment, charcoal (Darco G-60) treatment and large scale paper chromatography. The assay method used for this cellulolytic activity was the in vitro rumen fermentation technique. Factor activity of the materials studied was found to be in the top portion (above R_f 0.65) of the large scale phenol chromatograms. Further fractionation of the eluate from this section (using yeast extract as the starting material), by paper chromatography, indicated that the cellulolytically active factors were valine, proline, leucine and isoleucine. Water extracts of this portion, from all three materials, contained these amino acids in common. The known amino acids, valine, proline and the leucines were found to be cellulolytically active when used in the in vitro rumen fermentation. Proline exerted an additive effect in combination with either valine or the leucines, while valine and the leucines when tested together did not show this effect. Valeric acid (one of the cellulolytic factors of rumen juice), the amino acids valine, proline and the leucines and yeast extract did not show any appreciable additive effect upon cellulose digestion when tested in various1 combinations.