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Radiocesium accumulation in edible wild mushrooms from coniferous forests around the Nuclear Centre of Mexico.

Cs-137 and K-40 have been determined in soil samples and in wild edible mushrooms from a forest ecosystem located at the Nuclear Centre of Mexico (NCM) and in several surrounding localities. The transfer factors for Cs-137 were studied in 21 mushroom species from 1993 to 1997. The Cs-137 and K-40 determinations were performed using a gamma spectrometer system of low level counting with a high purity germanium (HPGe) detector. The local mushroom species that were found to show higher Cs-137 transfer factors were Clavariadelphus truncatus, Cortinarius caerulescens, Gomphus floccosus and Lyophyllum decastes. The Cs-137 levels obtained at the NCM in some mushroom samples were slightly lower than those from surrounding localities indicating that the nuclear facility has not emitted Cs-137 to the atmosphere.

Agaricales↗

The molecular genetics of cultivated mushrooms.

The types, economic significance and methods of production of the principal cultivated mushrooms are described in outline. These organisms are all less than ideal for conventional genetic analysis and breeding, so molecular methods afford a particular opportunity to advance our understanding of their biology and potentially give the prospect of improvement by gene manipulation. The sequences described are limited to those found in GenBank by August 1999. The gene sequences isolated from the white button mushroom Agaricus bisporus, the shiitake Lentinula edodes, the oyster mushrooms Pleurotus spp., the paddy straw mushroom Volvariella volvacea and the enotake Flammulina velutipes are described. The largest group are genes from A. bisporus, which includes 29 for intracellular proteins and 12 for secreted proteins. In comparison, only a total of 26 sequences can be reported for the other cultivated species. A. bisporus is also the only cultivated species for which molecular karyotyping is already supported by reliable markers for all 13 of its chromosomes.

Agaricales↗

Accumulation factors of mercury in mushrooms from Zaborski Landscape Park, Poland.

Total mercury concentrations were determined by cold-vapour atomic absorption spectroscopy (CV-AAS) in 117 samples of caps, 117 of stalks and 47 of whole fruiting bodies of 13 species of wild mushrooms and in 164 underlying soil substrate collected from Zaborski Landscape Park during 1997 and 1998. The study area is a background, forested site with rural landscape and no known local sources of mercury emission. Mean mercury concentrations in mushrooms varied widely (range: 50 +/- 20 to 3700 +/- 1700 ng/g, dry matter) depending on the site and mushroom species investigated. However, mercury concentrations in soil samples varied less (range: 3.0 +/- 3.0 to 43 +/- 17 ng/g dry matter). Fruiting bodies of Common Puffball (Lycoperdon perlatum) and King Bolete (Boletus edulis) contained the greatest concentrations of mercury of 3700 +/- 1700 and 2600 +/- 1200 ng/g dry matter, respectively. A positive correlation existed between mercury concentrations in the caps of Slippery Jack (Suillus luteus) and Fly Agaric (Amanita muscaria) (p < 0.01) and mercury concentrations in corresponding soils. However, concentrations of mercury in The Sickener (Russula emetica) was negatively correlated with its soil substrate (p < 0.01). Bioconcentration factors (BCFs: concentrations ratios of mercury in mushroom to soil) of total mercury in whole fruiting bodies or caps were greatest for Common Puffball (L. perlatum), Larch Bolete (Suillus grevillei) and King Bolete (B. edulis) and varied between 130 +/- 78 and 160 +/- 120, while for the other species BCFs were between 4.0 +/- 6.0 and 61 +/- 20 in caps, and 4.4 +/- 3.1 and 70 +/- 68 in stalks. The concentration ratios of Hg in cap to stalk were from 1.1 +/- 0.5 for Poison Pax (Paxillus involutus) to 2.7 +/- 1.7 in Larch Bolete (S. grevillei).

Agaricales↗

Chemoprevention of preneoplastic liver foci development by dietary mushroom Agaricus blazei Murrill in the rat.

The chemopreventive potential of an Agaricus blazei (Ab) Murrill mushroom meal was investigated in a medium-term rat liver carcinogenesis assay. Male Wistar rats initiated for hepatocarcinogenesis with diethylnitrosamine (DEN, 200 mg/kg i.p.) were fed during a 6-week period with the dry powdered mushroom strains Ab 29 or 26, each one with opened (OB) or closed basidiocarp (CB), mixed at 10% level in a basal diet. All experimental animals and controls were subjected to partial hepatectomy at week 3 and killed at week 8. Chemopreventive activity of the mushroom meal was observed for the Ab 29 (OB and CB) and Ab 26 (CB) strains in terms of the number of putative preneoplastic altered foci of hepatocytes which express either the enzyme glutathione S-transferase, placental form (GST-P+) or the transforming growth factor-alpha, and for the Ab 29 (OB) and Ab 26 (CB) strains on the size of GST-P+ foci. This was associated with inhibition of foci cell proliferation in the animals fed the Ab 29 (OB) and Ab 26 (CB) strains. The results suggest that the protective influence of the Ab meal against the DEN potential for rat liver carcinogenicity depends on both the strain and period of mushroom harvest.

Agaricus↗

The mutagenicity of some edible mushrooms in the Ames test.

The mutagenic activity of five wild and two cultivated species of edible mushrooms was studied in the Ames Salmonella/microsome test system. The wild mushrooms tested were four species of the genus Lactarius (L. necator, L. torminosus, L. helvus and L. rufus) and bolete (Boletus edulis). The cultivated species were champignon (Agaricus bisporus) and shiitake (Lentinus edodes). All the mushrooms were mutagenic to tester strains sensitive to base-pair substitution mutagens, and L. necator, L. rufus and B. edulis also had some frameshift activity. Metabolic activation was not required and the mutagenic activity could be detected even in boiled mushroom extracts. After fractionation with organic solvents (ethanol followed by diethyl ether) the activity was recovered in the ether phase as well as the aqueous phase in the case of L. necator, but remained in the aqueous phase of the A. bisporus and Lentinus edodes extracts.

Basidiomycota↗

NMR imaging of white button mushroom (Agaricus bisporis) at various magnetic fields.

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) have been applied to visualize physiological phenomena in plants and agricultural crops. Imaging sequences that result in contrast of a combination of parameters (e.g., proton density, T1, T2, T2*) cannot be used for a correct and unique interpretation of the results. In this study multiecho imaging together with monoexponential T2 decay fitting was applied to determine reliable proton density and T2 distributions over a mushroom. This was done at three magnetic field strengths (9.4, 4.7, and 0.47 T) because susceptibility inhomogeneities were suspected to influence the T2 relaxation times negatively, and because the influences of susceptibility inhomogeneities increase with a rise in magnetic field strength. Electron microscopy was used to understand the different T2's for the various tissue types in mushrooms. Large influences of the tissue ultrastructure on the observed T2 relaxation times were found and explained. Based on the results, it is concluded that imaging mushrooms at low fields (around or below 0.47 T) and short echo times has strong advantages over its high-field counterpart, especially with respect to quantitative imaging of the water balance of mushrooms. These conclusions indicate general validity whenever NMR imaging contrast is influenced by susceptibility inhomogeneities.

Agaricus↗

Quantitative 1H-NMR imaging of water in white button mushrooms (Agaricus bisporus).

MRI represents a valuable tool for studying the amount and physical status of water in plants and agricultural products, for example, mushrooms (Agaricus bisporus). Contrast in NMR images originates from the mixed influence of the fundamental NMR parameters, amongst others, spin-density, T2- and T1 relaxation processes. Maps of these parameters contain valuable anatomical and physiological information. They can, however, be severely distorted, depending on the combination of parameter settings and anatomy of the object under study. The influence of the tissue structure of mushrooms, for example, tissue density (susceptibility inhomogeneity) and cell shape on the amplitude, T2, and T1 images is analyzed. This is achieved by vacuum infiltration of the cavities in the mushroom's spongy structure with Gd-DTPA solutions and acquiring Saturation Recovery-Multispin Echo images. It is demonstrated that the intrinsic long T2 values in the cap and outer stipe tissue strongly relate to the size and geometry of the highly vacuolated cells in these spongy tissues. All observed T2 values are strongly affected by susceptibility effects. The T2 of gill tissue is shorter than T2 of the cap and outer stipe, probably because these cells are less vacuolized and smaller in size. The calculated amplitude images are not directly influenced by susceptibility inhomogeneities as long as the observed relaxation times remained sufficient long. They reflect the water distribution in mushrooms best if short echo times are applied in a multispin echo imaging sequence at low magnetic field strength.

Agaricus↗

Purification and characterization of RNA polymerase II resistant to alpha-amanitin from the mushroom Agaricus bisporus.

The DNA-dependent RNA polymerases II or B (ribonucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) from the mushroom Agaricus bisporus has been purified to apparent homogeneity. The purification procedures involve precipitation with polyethylenimine, selective elution of RNA polymerase II from the polyethylenimine precipitate, ammonium sulfate fractionation, DEAE-cellulose chromatography, CM-cellulose chromatography, and exclusion chromatography on Bio-Gel A-1.5M. With this procedure 11 mg of RNA polymerase II is recovered from 1.5 kg of mushroom tissue. RNA polymerase II from Agaricus bisporus has 12 subunits with the following molecular weights: 182,000, 140,000, 89,000, 69,000, 53,000, 41,000, 37,000, 31,000, 29,000, 25,000, 19,000, and 16,500. Purified RNA polymerase II from Agaricus bisporous was half-maximally inhibited by the mushroom toxin alpha-amanitin at a concentration of 6.5 microgram/mL (7 X 10(-6) M), which is 650-fold more resistant than mammalian RNA polymerases II. The apparent Ki for the alpha-amanitin-RNA polymerase complex was estimated to be 12 X 10(-6) M. The activity of purified RNA polymerase II from the mushroom was quite typical of other eukaryotic RNA polymerase II with regard to template preference, salt optima, and divalent metal cation optima.

Agaricales↗

Contents of vitamins, mineral elements, and some phenolic compounds in cultivated mushrooms.

The aim of the study was to determine the contents of mineral elements (Ca, K, Mg, Na, P, Cu, Fe, Mn, Cd, Pb, and Se), vitamins (B(1), B(2), B(12), C, D, folates, and niacin), and certain phenolic compounds (flavonoids, lignans, and phenolic acids) in the cultivated mushrooms Agaricus bisporus/white, Agaricus bisporus/brown, Lentinus edodes, and Pleurotus ostreatus. Selenium, toxic heavy metals (Cd, Pb), and other mineral elements were analyzed by ETAAS, ICP-MS, and ICP methods, respectively; vitamins were detected by microbiological methods (folates, niacin, and vitamin B(12)) or HPLC methods (other vitamins), and phenolic compounds were analyzed by HPLC (flavonoids) or GC--MS methods (lignans and phenolic acids). Cultivated mushrooms were found to be good sources of vitamin B(2), niacin, and folates, with contents varying in the ranges 1.8--5.1, 31--65, and 0.30--0.64 mg/100 g dry weight (dw), respectively. Compared with vegetables, mushrooms proved to be a good source of many mineral elements, e.g., the contents of K, P, Zn, and Cu varied in the ranges 26.7--47.3 g/kg, 8.7--13.9 g/kg, 47--92 mg/kg, and 5.2--35 mg/kg dw, respectively. A. bisporus/brown contained large amounts of Se (3.2 mg/kg dw) and the levels of Cd were quite high in L. edodes (1.2 mg/kg dw). No flavonoids or lignans were found in the mushrooms analyzed. In addition, the phenolic acid contents were very low.

Agaricales↗

Mercury content and its bioconcentration factors in wild mushrooms at Łukta and Morag, northeastern Poland.

Total concentrations of mercury were determined using cold-vapor atomic absorption spectroscopy (CV-AAS) in the fruiting bodies of 16 species of wild mushrooms and underlying soil (0-10 cm) substrates collected in the areas of the Communes of Morag and Łukta in the county of Ostróda in northeastern Poland in 1997-1998. A total of 174 composite samples of caps, 174 stalks, 80 whole fruiting bodies (collectively 1254 specimens), and 252 soils were examined. Among several species of mushrooms analyzed, the greatest concentrations were between 1300 and 71000 ng.g(-1) of dry matter. These levels were found in the caps of Sweating mushroom (Clitocybe rivulosa), King Bolete (Boletus edulis), and Common Puffball (Lycoperdon perlatum) and also were characterized by the highest bioconcentration factors (BCF) for Hg, which ranged between 160 +/- 82 and 110 +/- 34. The cap to stalk quotient for mercury concentrations was approximately 2 for most of the species except Poison Pax (Paxilus involutus), which had a greater concentration in caps than in stalks and a quotient of 4.4 +/- 7.2. Hg concentrations in the underlying soil substrates (0-10 cm layer) ranged between 21 +/- 21 and 390 +/- 130 ng.g(-1) of dry matter. The results showed that the consumption of mushrooms, considered to be the sole dietary source of mercury at the highest or mean element concentrations found, is not hazardous at daily ingestion rates of less than 70 and 210 g of fresh product, which would result in a hazard index value of less than unity.

Agaricales↗

Bimodal polymer mushrooms: compressive forces and specificity toward receptor surfaces.

End-grafted poly(ethylene glycol) (or PEG) polymer chains are used to extend the in vivo circulation time of targeted liposomes and nanoparticles; however, the most efficacious structure for also imparting high target specificity remains unknown. Using the surface force apparatus, we have measured the specific and nonspecific forces between bimodal mixtures of grafted polymer mushrooms and model receptor surfaces. Specifically, supported lipid membranes anchoring 2000 or 5000 Da PEG with a controlled fraction of PEG(2000) bearing biotin ligands were compressed against opposing streptavidin surfaces. The presence of the longer 5000 Da chain increased the steric repulsion of the bimodal mushroom layer and thus decreased the net adhesive force when shorter chains were ligated. However, the 5000 Da chain did not detectably alter the distance where ligand-receptor binding occurs and adhesion begins. This latter result is in good agreement with theoretical predictions based on summing the repulsive steric and attractive bridging forces. Further, all ligated structures adhered to receptors under both static and dynamic fluid flow conditions. The dynamic movement of the flexible PEG tethers permitted ligand-receptor bonds to form far beyond the equilibrium edge of the bimodal mushroom layer. This work demonstrates that liposome targeting should be enhanced by grafting ligands to liposomes with a tether that has a contour length longer than the equilibrium height of the bimodal mushroom layer.

Biotin↗

Biology, life table and host specificity of the mushroom pest, Brennandania lambi (Acari: Pygmephoroidea).

Biology and life table parameters of Brennandania lambi (Krczal) were studied at different temperatures while feeding on white mushroom (Agaricus bisporus) mycelium cultured on mushroom compost. The duration of egg and larva development, preoviposition and oviposition period, female longevity, and the time to 50% mortality declined as temperature increased from 16 to 28 degrees C. The threshold temperature of development (female) was 9 degrees C and the thermal constant for completion of development (female) was 195 day-degrees. At 16, 20. 24 and 28 degrees C, the total fecundity (eggs/female) was 71, 67, 66 and 57, respectively and the daily fecundity rate (eggs/female/day) was 5.6, 8.7, 8.7 and 9.1, respectively. The sex ratio (female/male) ranged from 1.9 to 2.1 at 16-28 degrees C. At 16, 20, 24 and 28 degrees C, the intrinsic rate of natural increase (rm) was 0.11, 0.18, 0.22 and 0.27, respectively, and the population doubling time was 6.1. 3.9. 3.2 and 2.5 days, respectively. All life stages of the mite died when exposed to 35 degrees C constant temperature for 24h. or to 32 degrees C constant temperature for 12 days or to 31-35 degrees C (average 32.9 degrees C) ambient temperature for 4 days. Brennandania lambi completed development only when fed on Ag. bisporus mycelium growing on mushroom compost. It could not survive on mushroom mycelia of Auricularia auricula. Au. polytricha, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes, Pleurotus ostreatus, P. sajor-caju and Tremella juciformis.

Agaricales↗

Antihypertensive and metabolic effects of whole Maitake mushroom powder and its fractions in two rat strains.

Maitake mushroom has been reported to favorably influence hypertension and diabetes mellitus. The purpose of this study was to compare the effects of whole Maitake mushroom powder and two extracts designated as ether soluble (ES) and water soluble (WS) on Zucker fatty rats (ZFR), a model of insulin resistance, and on spontaneously hypertensive rats (SHR), a model of genetic hypertension. In the initial study, we followed four groups of eight ZFR and SHR receiving special diets: a baseline diet (BD), BD + whole Maitake mushroom powder (20% w/w), BD + fraction ES (0.10% w/w), and BD + WS (0.22% w/w). Different effects of these dietary regimens on the 2 rat strains were found. At 35 days, only consumption of the ES diet significantly decreased systolic BP (SBP) in SHR (average 197 vs. 176 mm Hg, p < 0.001), while in ZFR only the groups consuming the whole Maitake and WS diets showed significantly decreased SBP (138 vs. 120-125 mm Hg, p < 0.001). A challenge test with losartan (an angiotensin II receptor blocker) indicates that angiotensin II does not play a major role in SBP regulation of ZFR, but does in SHR where consumption of ES relative to other groups significantly lowered activity of this system. In SHR, glucose, cholesterol, circulating insulin and HbA1C were virtually similar among all dietary groups; but whole Maitake (-22%), ES (-120%) and WS (-80%) diets were associated with decreased triglycerides, and the ES diet with lowered serum creatinine (-29%). In ZFR, circulating insulin and HbA1C were significantly decreased in the whole Maitake powder and ES groups, and tended to be lower in the WS group compared to control. In the ensuing studies, we gavaged ZFR once daily with water (control), 44 mg fraction WS, or 44 mg fraction WS plus 100 microg niacin-bound chromium (NBC). Oral gavage of WS clearly lowered SBP and circulating glucose concentrations, more so with the addition of chromium. We conclude that the examined forms of Maitake mushroom have antihypertensive and antidiabetic potential which differ among rat strains. The ES fraction may decrease SBP in SHR via alteration in the renin-angiotensin system.

Agaricales↗

Mercury in wild mushrooms and underlying soil substrate from the great lakes land in Poland.

Fifteen species of wild mushrooms and underlying soil samples collected in a virgin landscape of Augustowska Forest in northeastern Poland in 1997-98 were analyzed for total mercury to evaluate the status of contamination and usefulness of higher mushrooms as possible bioindicators of mercury pollution. Among the 15 species analyzed, Pinewood King Bolete, Scaly Tooth and King Bolete showed relatively high bioconcentration factors (BCF: dry-weight normalized concentrations of mercury in mushrooms relative to concentrations in soil) for mercury, which varied between 69 and 110. These three species were also characterized by great concentrations of total mercury in caps (between 2,000 +/- 800 and 2,300 +/- 1,100 ng g-1 dry wt) and stalks (between 850 +/- 390 and 1,000 +/- 500 ng g-1 dry wt.). Species such as Red-hot Milk Cap, Poison Pax and Common Chantherelle had mercury BCFs of less than 1, while Gipsy Bolete, Orange Birch Bolete, Brown Scaber Stalk, Variegated Bolete, Sandy Knight-cap and Yellow-cracking Bolete were weak or moderate mercury accumulators with BCFs between 1 and 40. Concentrations of mercury in mushrooms were greater than the tolerance limits suggested for mercury in plant foods.

Agaricales↗

210Po bioaccumulation by mushrooms from Poland.

The paper presents results on 210Po activity concentration measured in mushroom samples collected in northern Poland (Białogard and Elblag areas). Among 20 species of wild mushrooms, King Bolete (Boletus edulis), accumulated 210Po in the highest degree. Therefore this species of higher mushrooms is an excellent bioindicator for 210Po radioactivity in the land environment. Finally, the effective dose of polonium emission was calculated for a consumer of King Bolete. Wild mushroom consumption contributed up to 37 microSv to the effective dose in an individual consuming about 5 kg (fresh weight) of heavily contaminated Boletus edulis species per year.

Agaricales↗

Glycoinositolphosphosphingolipids (basidiolipids) of higher mushrooms.

The basidiolipids of six mushroom species, i.e. the basidiomycetes Amanita virosa (engl., death cup), Calvatia exipuliformis (engl., puffball), Cantharellus cibarius (engl., chanterelle), Leccinum scabrum (engl., red birch boletus), Lentinus edodes (jap., Shiitake), and Pleurotus ostreatus (engl., oystermushroom), were isolated, and their chemical structures investigated. All glycolipids are structurally related to those of the Agaricales (engl., field mushroom). They are glycoinositolphosphosphingolipids, their ceramide moiety consisting of t18:0-trihydroxysphinganine and an alpha-hydroxy long-chain fatty acid. In contrast to a previous study [Jennemann, R., Bauer, B.L., Bertalanffy, H., Geyer, R., Gschwind, R.M., Selmer, T. & Wiegandt, H. (1999) Eur. J. Biochem. 259, 331--338], the glycoside anomery of the hexose (mannose) connected to the inositol of all investigated basidiomycete glycolipids, including the basidiolipids of Agaricus bisporus, was determined unequivocally to be alpha. Therefore, the root structure of all basidiolipids consists of alpha-DManp-2Ins1-[PO(4)]-Cer. In addition, for some mushroom species, the occurrence of an inositol substitution position variant, alpha-Manp-4Ins1-[PO(40]-Cer, is shown. The carbohydrate of chanterelle basidiolipids consists solely of mannose, i.e. Cc1, Man alpha-3 or -6Man alpha; Cc2, Man alpha-3(Man alpha-6)Man alpha-. All other species investigated show extension of the alpha-mannoside in the 6-position by beta-galactoside, which, in some instances, is alpha-fucosylated in 2-position (Fuc alpha-2)Gal beta-6Man alpha-. Further sugar chain elongation at the beta-galactoside may be in 3- and/or 6-position by alpha-galactoside, e.g. Ce4, Po2, Gal alpha-3-(Gal alpha-6)(Fuc alpha-2)Gal beta-6Man alpha-, whereas A. virosa, Av-3, has a more complex, highly alpha-fucosylated terminus, Gal alpha-3 (Fuc alpha-2)(Fuc alpha-6)Gal alpha-2(Gal alpha-3)Gal beta-6Man alpha-. L. edodes basidiolipids show further elongation by alpha-mannoside, e.g. Le3, Man alpha-2Man alpha-6Gal alpha-3(Fuc alpha-2)Gal beta-6Man alpha-, C. exipuliformis glycolipid by alpha-glucoside, i.e. Ce3, Glc alpha-6Gal beta-6Man alpha-. Basidiolipid Ls1 from L. scabrum, notably, has a 3-alpha-mannosylated alpha-fucose, i.e. Gal alpha-6(Man alpha-3Fuc alpha-2)Gal alpha-6Gal beta-6Man alpha-. In conclusion, basidiolipids, though identical in their ceramide constitution, display wide and systematic mushroom species dependent variabilities of their chemical structures.

Agaricales↗

[Immunofluorescence test in the diagnosis of mushroom worker's lung (author's transl)].

Growing and harvesting a new edible mushroom (Pleurotus florida mushroom--oyster mushroom) liberates a high amount of spores the inhalation of which causes symptoms similar to those of "farmer's lung". The Ouchterlony test detects precipitins against antigens of the spore membrane only in cases with high serum antibody levels, i.e. only one in eight sufferers from the disease had a positive antibody test. Because of this, indirect immunofluorescence was used as a more sensitive method for serum antibody detection: all mushroom workers with clinical symptoms were found to have precipitating antibodies. The test is, therefore, superior to the Ouchterlony one, is simpler and saves time. Furthermore, the immunoglobulin class can easily be obtained at the same time.

Alveolitis, Extrinsic Allergic↗

Vitamin D2 from irradiated mushrooms significantly increases femur bone mineral density in rats.

A method has been optimized for the conversion of ergosterol in mushrooms to vitamin D2, and the vitamin D-enriched mushrooms have been tested for bioavailability of vitamin D2 using a rat model. Femur bone mineral density (BMD) of the experimental group of animals fed with vitamin D2 (1 microg/d) obtained from irradiated mushrooms was significantly increased. Femur BMD of two groups was significantly higher. Femur BMD of the experimental group was significantly elevated compared to initial femur BMD of the study group. Data indicate that vitamin D2 from ultraviolet (UV)-irradiated mushrooms was well absorbed and metabolized in animals.

Agaricales↗