Purine degradation in the edible mushroomAgaricus bisporus

Abstract

Agaricus bisporus is able to use urate, allantoin, allantoate, urea and alloxanate as nitrogen sources for growth. The presence of urate oxidase, allantoinase, ureidoglycolase and urease activities, both in fruit bodies and mycelia, points to a degradative pathway for urate similar to that found in various microorganisms. So far all efforts to demonstrate the enzyme responsible for allantoate degradation failed. A urease inhibitor appeared to be present in cell-free extracts from fruit bodies.

Argininosuccinate synthetase and argininosuccinate lyase: two ornithine cycle enzymes from Agaricus bisporus

“…b-Methylaspartate and d-N-acetylornithine were found to block ASS activity and caused 14 C-citrulline to accumulate. The ornithine cycle has been demonstrated to be the main route for urea synthesis (Reinbothe et al 1967), although the contribution of the purine degradative pathway could not be excluded (Hammond 1979;de Windt et al 2002). It is known for members of the family Agaricaceae that they accumulate substantial amounts of urea in their fruiting body.…”