Changes in Amino Acids and Urea in Cultivated Mushroom, Agaricus bisporus, as Influenced by Nutrient Supplementation of Compost during Growth Cycle

Abstract

Amino acids and urea in the cultivated mushroom, Agaricus bisporus, were studied as changes in chemical composition may influence the nutrition and alter the quality of the mushroom. Amino acids were assayed by column chromatography, while urea, total nitrogen, and dry matter were determined by conventional methods in alcohol extracts and fresh tissues. Where gelatin was added to the compost, the amounts of alanine, ammonia, and arginine decreased, but aspartic acid increased. With the addition of hydrolyzed casein, arginine decreased. In the extracts, both the sum of the nitrogen in the various compounds and the total nitrogen by the Kjeldahl method increased toward the end of the growing cycle. Calculations showed 79% to complete recovery of nitrogen in the alcohol extracts. Mushroomshave for centuries been prized as a delicacy. They are known as a food of excellent nutritive value, low in calories and relatively high in proteins and amino acids.Fitzpatrick, Esselen. and Weir (5) found that the total nitrogen content was 0.5%, (fresh weight basis). of which 63% was in the form of protein. Workers at the University of Massachusetts investi-

Morphogenesis and free amino acid composition of the ascomyceteSphaerostilbe repensas influenced by nitrogen and calcium

“…This emphasizes the key role of these amino acids in the metabolism and storage of nitrogen in this fungus. The present data are in good agreement with those obtained for several fungi including: Neurospora crassa [12], Agaricus bisporus [13], Aspergillus flaous [14] and Phymatotrichum omnivorum [15].…”

Mushroom ninhydrin-positive compounds. Amino acids, related compounds, and other nitrogenous substances found in cultivated mushroom, Agaricus campestris

“…Phosphoethanolamine, methionine sulfoxides, a-aminoadipic acid, and ethanolamine have been reported by Craske and Reuter (1965) in Boletus edulis. Taurine and ammonia have been recently reported by Kissmeyer-Nielsen et al (1966) in A. bisporus.…”

“…The introduction of the automatic and continuous ion-exchange chromatographic technique by these workers for the accurate separation, identification, and quantitative determination of amino acids and other ninhydrin-positive compounds in unknown mixtures has fulfilled the need for a method of analysis which does not possess the shortcomings of the earlier conventional methods. Kissmeyer-Nielsen et al (1966) have recently used the Technicon Auto Analyzer for assaying simple 2-propanol extracts of the edible mushroom, A. bisporus. The present paper presents the results obtained by the use of a novel isolation procedure, which included features of both solvent fractionation and other methods of concentration of the compounds into a suitable fraction.…”

Amino acid composition of the morel mushroom

“…In the case of the cultivated mushroom, Agaricus bisporus, alanine, ammonia, and arginine contents of the tissue decreased, and the aspartic acid content increased when gelatin was added to the compost (Kissmeyer-Nielsen et al, 1966). However, when hydrolyzed casein was added to the compost, the arginine content decreased.…”