Agaritine (N-(gamma-L(+)-glutamyl)-4-hydroxymethylphenylhydrazine) is a phenylhydrazine derivative found in the cultivated Agaricus mushroom which is claimed to give rise to carcinogenic products when metabolized. The stability of a synthetic sample of agaritine was tested in water and methanol. In tap water kept in open vials, agaritine was totally degraded within 48h. Since agaritine degradat...

Individual tocopherol profile of five Agaricus mushroom species, widely consumed in Portugal, was obtained by a normal-phase high-performance liquid chromatography (NP-HPLC). It was used a simple solid-liquid extraction procedure without saponification step and the chromatographic separation was achieved using a YMC-Pack Polyamine II column using an isocratic elution with hexane/ethyl acetate (...

Tyrosinase exhibits catalytic activity for the ortho-hydroxylation of monophenols to diphenols as well as their subsequent oxidation to quinones. Owing to polymerization of these quinones, brown-coloured high-molecular-weight compounds called melanins are generated. The latent precursor form of polyphenol oxidase 4, one of the six tyrosinase isoforms from Agaricus bisporus, was purified to homo...

The internal stipe necrosis of cultivated mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana, a species of the Enterobacteriaceae. Recently, Ewingella americana was isolated from cultivated white button mushrooms in Korea evidencing symptoms of internal stipe browning. Its symptoms are visible only at harvest, and appear as a variable browning reaction in the center of...

Dysfunction of the mitochondrial respiratory chain and increased oxidative stress is a striking phenomenon in the brain of aged individuals. For this reason there has been a constant search for drugs and natural products able to prevent or at least to mitigate these problems. In the present study the effects of an aqueous extract of Agaricus blazei, a medicinal mushroom, on the oxidative state ...

Agaricus arvensis, a newly isolated basidiomycetous fungus, was found to secrete efficient cellulases. The strain produced the highest endoglucanase (EG), cellobiohydrolase (CBH) and beta-glucosidase (BGL) activities of 0.3, 3.2 and 8U/mg-protein, respectively, with rice straw as the carbon source. Saccharification of the woody biomass with A. arvensis cellulase as the enzyme source released a ...

Agrobacterium tumefaciens is known to transfer parts of its tumor-inducing plasmid to filamentous fungi including Agaricus bisporus. We have used this transformation system to transform germinating basidiospores of A. bisporus. Analysis of hygromycin B-resistant clones showed that the T-DNA integrated at random sites and in multiple copies into the host genome. Furthermore we have been able to ...

Partially purified virus preparations from sporophores of Agaricus bisporus affected with LaFrance disease had up to a 15-fold-higher RNA-dependent RNA polymerase activity than did comparable preparations from healthy sporophores. Enzyme activity was dependent upon the presence of Mg2+ and the four nucleoside triphosphates and was insensitive to actinomycin D, a-amanitin, and rifampin. The 3H-l...

The position and composition of Macrolepiota within the Agaricaceae and its phylogenetic relationships with other members of the family were investigated, using both molecular (ITS and LSU rDNA sequences) and morphological characters. The molecular data separate the genus into two clades. The first clade comprises M. procera, M. mastoidea, M. clelandii and allies and is a sister group of Leucoa...

BACKGROUND One of the main problems for the preservation of genetics resources of Agaricus subrufescens is to maintain the viability of the strains because the mycelium is very sensitive to cooling and therefore it ages rapidly. AIMS Evaluate the viability of A. subrufescens strains stored as cultures on sorghum grain (spawn) at different temperatures. METHODS Eighteen strains of A. subrufe...