Studies on the metabolism of urea and other nitrogenous compounds in Chlorella ellipsoidea: Iii assimilation of urea

Abstract

Assimilation of urea by Chlorella ellipsoidea was investigated by using 14C-urea. It was revealed that urea carbon metabolized by the N-starved cell was almost quantitatively recovered in carbon dioxide under dark-aerobic conditions. The rate of urea consumption was considerably influenced by the N-content of algal cells, practically no metabolism of urea being observed with the cells containing more than 7 per cent N on a dry weight basis. Similar results were also obtained when urea was replaced with ammonia as nitrogen source. Based on the results obtained, a tentative scheme for the assimilation process of urea in Chlorella was proposed. © 1960 Oxford University Press.