Formation of Extra-cellular Nitrogen Compounds by Fungi

Abstract

IN the course of work in this Laboratory on the nitrogen metabolism of mould fungi, it has frequently been observed that much less than the total amount of nitrogen supplied initially in the medium in the form of nitrate or ammonium salt is recovered in the fungus mycelium, although a high level of readily assimilated carbohydrate is present in the culture medium. Similar results have been obtained by other workers¹; but it is not clear whether they are to be explained by incomplete assimilation of the nitrogen source or by the formation by the fungus of complex nitrogen compounds which either remain in, or are excreted into, the medium. A quantitative study of the uptake of inorganic nitrogen by fungi was therefore undertaken, using in the first place a strain of Scopulariopsis brevicaulis.