The Incorporation of 14C from Sodium Acetate-2-14C into the Amino Acids of the Soil-Inhabiting Nematode, Caenorhabditis briggsae

Abstract
1. The nematode, Caenorhabditis briggsae was cultured axenicaily in a mixture of chick embryo extract, autoclaved liver extract and sodium acetate-2-14C. A protein hydrolysate was prepared from the worms and the eggs which were collected from the cultures. 2. Chromatography and radioautography were carried out in a study of the amino acid composition of the hydrolysate. The following amino acids were found labelled: aspartic acid, glutamic acid, alanine, proline, glycine, serine. Cystein and cystine were oxidized to cysteic acid which was also labelled. The following amino acids were not labelled: arginine, histidine, lysine, methionine, threonine, tyrosine, valine and the combined spot representing phenylalanine, leucine and isoleucine. Tryptophane would have been destroyed by our method of hydrolysis. 3. Since the labelled amino acids are synthesized by the worm, it is suggested, tentatively, that they are not required in an otherwise adequate diet. So far as the unlabelled amino acids are concerned, it is suggested, on the basis of the results of certain culture experiments (published separately) that, with the probable exception of tyrosine, they are essential in the diet of C. briggsae.