Abstract
The ability of three ecologically important ectomycorrhizal fungi,
Suillus bovinus, Amanita muscaria and
Hebeloma crustuliniforme to utilize each of the biologically active amino acids as sole nitrogen source was assessed, and their growth was compared with that obtained on the two mineral N sources, ammonium and nitrate.
Aspartic and glutamic acids, and amides, together with arginine, alanine and serine all supported growth comparable with that on ammonium in each of the fungi, whereas cysteine, methionine, proline, threonine, tryptophane and tyrosine were not utilized. Interspecific differences were observed in the abilities to utilize the remaining amino compounds.
The results are discussed in relation to availability of amino acids in soils and the nitrogen nutrition of the fungi and of their host plants.