A method for determining 2-aminoethane-phosphonic acid in rumen contents

Abstract

The work described is an attempt to develop a reliable method for determining AEP when mixed with related substances from micro-organisms in the rumen. Hydrochloric acid hydrolysates of rumen contents, rumen bacteria, rumen ciliate protozoa and clarified rumen contents were applied to a column (10 × 1 cm) of Dowex 50–X8, eluted with 0·6 N hydrochloric acid and 2·4-ml fractions collected. Inorganic phosphorus was separated in column fractions 2–10 and AEP appeared in fractions 11–23.

When fractions containing AEP were spotted on to Whatman No. 1 filter-paper strips the developed chromatograms showed six ninhydrin-positive spots in addition to that of AEP, which was the slowest acid to migrate (R_F= 0·3). The substance giving spot No. 4, another phosphonic acid (R_F= 0·59), was present in ciliate protozoa and ciliate-free fractions of rumen contents, whereas AEP was confined to protozoa. A highly significant correlation was found between the AEP concentrations and protozoal counts in samples of rumen contents collected at different intervals. It is therefore suggested that the concentration of AEP can be used as a marker of the protozoal growth in the rumen.