In a previous study (l), the composition of total cellular amino acids of the ciliated protozoan, Tetrahymena pyriformis (formerly, T. geleii), was presented together with other pertinent data concerning the nitrogen metabolism of this organism. The present investigation was undertaken to obtain information on the free and nonprotein amino acids of this protozoan cell, inasmuch as the nonprotei...

A simple, efficient procedure for removing lactic acid and for reducing nonprotein nitrogen and ash in lactic acid whey has been developed. The procedure consists of culturing Candida ingens on the whey. This organism could assimilate >98% of the lactic acid and approximately 40% of the nonprotein nitrogen. Ash reduction of up to 45% resulted from precipitation of calcium apatite due to the inc...

In patients with renal insufficiency, the elevated plasma nonprotein nitrogen cannot be accounted for solely by the rise in the urea nitrogen (2). It is known that other nitrogenous materials such as creatinine and uric acid contribute to this elevation. Since free amino acids also contribute to the nonprotein, nonurea nitrogen of plasma, several investigators have determined the amino acid com...

Massive accumulation of l-canavanine, the 2-amino-4-(guanidinooxy)butyric acid structural analog of l-arginine, occurs in many legumes. Accumulation of large amounts of this nonprotein amino acid results in large part from canavanine's protective efficacy; it forms an effective chemical barrier to predation, disease, and even competition with other plants. Diversion of metabolic resources for t...