Abstract
Abilities of washed suspension of rumen ciliate protozoa to form δ-aminovaleric acid (DAV) and some precursors of DAV were chromatographically and autoradiographically examined. DAV was accumulated linearly in the medium during incubation of the ciliates. When proline or ornithine was added to the medium, the amount of DAV was increased to the level over the control value. The amount of proline in the medium after incubation was increased by addition of ornithine, while the amount of ornithine was increased by addition of arginine. L-Proline-U-14C was converted to radioactive DAV by the ciliates. But the radioactive DAV was not converted further by them, so it seemed to be the end product in proline metabolism of rumen ciliates. L-Ornithine-U-14C was converted to proline and DAV, and L-arginine-U-14C was converted to ornithine, proline, DAV and four other unidentified compounds by the ciliates. All these results led us to presume that the serial pathway such as from arginine to ornithine, from ornithine to proline and from proline to DAV would exist in biochemical systems of rumen ciliate protozoa.
