Nitrogen-rich Medium Research Articles

Amino acids in Rhodotorula gracilis Rennerfelt.

BY cultivating Rhodotorula gracilis on media of varying composition, it is very easy to obtain yeast with different amounts of fat and protein1. A yeast rich in protein and poor in fat is obtained in a nitrogen-rich medium. In a nitrogen-poor medium, the yeast will be poor in protein and rich in fat. The protein content of the yeast may vary between 13 and 50 per cent of the dried matter. It seemed probable that such a large variation of the amount of yeast protein could change qualitatively the composition of the protein. We have investigated the amino-acid composition of yeast with low and high amounts of protein.