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PubMed2003

The ability of Drosophila mutants with defects in the central complex and mushroom bodies to learn and form memories.

One of the most important questions in the genetics of behavior is that of studies of the mechanisms of learning and memory. A convenient system for this is provided by Drosophila melanogaster, in which a whole series of mutations affecting the formation of different types of memory and learning have been obtained. The brain formations involved in these processes have been studied in parallel. Attention is currently focused on two main structures: the central complex and the mushroom bodies. These mediate the integration and storage of information accumulating during the process of learning. Mutants with defects in individual parts of the central complex and mushroom bodies have been obtained. Mutants simultaneously affecting the operation, development, or structure of the central part of the cerebral neural ganglion and the ability to learn and form memory traces are of particular interest. We have evaluated the learning ability of mutants with defects in the central complex (cexKS181 and ccbKS127) and mutants with defects in the mushroom bodies (mud1, mbm1, and cxbN71), using a method based on the conditioned reflex suppression of courtship. Memory defects were seen in cexKS181 and mud1 mutants.

Animals↗
PubMed2003

Inhibitory effect of 4-cyanobenzaldehyde and 4-cyanobenzoic acid on mushroom (Agaricus bisporus) tyrosinase.

Mushroom tyrosinase (EC 1.14.18.1), a copper containing oxidase, catalyzes both the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones. In the current study, the effects of 4-cyanobenzaldehyde and 4-cyanobenzoic acid on the monophenolase and diphenolase activities of mushroom tyrosinase have been studied. The results show that 4-cyanobenzaldehyde and 4-cyanobenzoic acid can inhibit both the monophenolase activity and the diphenolase activity of mushroom tyrosinase. The lag phase of tyrosine oxidation catalyzed by the enzyme was obviously lengthened, and the steady-state activity of the enzyme decreased sharply. 1.0 mM 4-cyanobenzaldehyde and 4-cyanobenzoic acid can lengthen the lag phase from 78 s to 134 and 115 s, respectively. Both 4-cyanobenzaldehyde and 4-cyanobenzoic acid can lead to reversible inhibition of the enzyme. The IC50 values of 4-cyanobenzaldehyde and 4-cyanobenzoic acid were estimated as 0.62 and 2.45 mM for monophenolase and as 0.72 and 1.40 mM for diphenolase, respectively. A kinetic analysis shows that 4-cyanobenzaldehyde and 4-cyanobenzoic acid are mixed-type inhibitors for the diphenolase. The apparent inhibition constants for 4-cyanobenzaldehyde and 4-cyanobenzoic acid binding with both the free enzyme and the enzyme-substrate complex have been determined and compared.

Agaricales↗
PubMed1989

Accelerated evolution of a false-truffle from a mushroom ancestor.

THE false-truffles (Hymenogastrales) are a group of basidomycetous fungi that produce underground truffle-like basidiocarps. They are generally believed to be independently derived from several mushroom lineages, but extensive morphological divergence often obscures recognition of these phylogenetic connections. Comparisons of mitochondrial DNA now demonstrate a surprisingly close relationship between species of false-truffles in the genus Rhizopogon (Hymenogastraceae) and the mushroom genus Suillus (Boletaceae). The striking morphological differences separating all Suillus species from Rhizopogon imply an acceleration in the rate of morphological change relative to molecular change during the evolution of these false-truffles from their mushroom ancestors. This acceleration can best be explained by rapid morphological divergence resulting from selective pressures which may have acted on a small number of developmental genes.

Base Sequence↗
PubMed2002

Influence of straw types and nitrogen sources on mushroom composting emissions and compost productivity.

The effects of different straw types and organic and inorganic nitrogen (N) sources on the chemical composition and odor concentration (OC) of mushroom composting emissions, compost parameters, and mushroom yield were examined using bench-scale and large-scale (windrows and aerated tunnels) composting systems. There were close correlations between the butanol or combined H(2)S+dimethyl sulfide (DMS) concentration and OC of air samples taken from different composting ingredients (r=0.83 and 0.76-0.87, P<0.01, for log(e)-transformed data). Differences in N availability, in terms of NH(3) and N losses during composting, were found between different N sources. Materials in which the N was less available (chipboard and digester wastes, cocoa shells, ammonium sulfate) produced lower mushroom yields than materials in which the N was more readily available (poultry manure, urea, brewers' grains, hop and molasses wastes, cocoa meal). Replacement of poultry manure with the other N sources at 50-100% or wheat straw with rape, bean, or linseed straw in aerated tunnel or windrow composts reduced the OC and emissions of odorous sulfur-containing compounds, but also reduced yield. Urea and cocoa meal may be suitable for "low odor" prewetting of straw, with addition of poultry manure immediately before aerated tunnel composting. Rape straw in compost reduces the formation of anaerobic zones and resulting odorous emissions, since it maintains its structure and porosity better than wheat straw.

Agaricales↗
PubMed1998

Study of stereospecificity in mushroom tyrosinase.

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase. Several enantiomorphs of monophenols and o-diphenols were assayed: L-tyrosine, D,L-tyrosine, D-tyrosine; L-alpha-methyltyrosine, D,L-alpha-methyltyrosine; L-dopa, D,L-dopa, D-dopa; L-alpha-methyldopa, D,L-alpha-methyldopa; L-isoprenaline, D,L-isoprenaline and D-isoprenaline. The Vmax values obtained for each series were the same. The electronic densities on the carbon atoms in the meta (C-3) and the para (C-4) positions of the benzene ring were determined by NMR assays. This value is related to the nucleophilic power of the oxygen atom belonging to the hydroxy group, which could explain the Vmax values experimentally obtained for the monophenolase and diphenolase activities of mushroom tyrosinase. The spatial orientation of the ring substituents led to lower Km values for L-isomers than for D-isomers. However, the Vmax values were the same for each series of isomers because spatial orientation did not affect the NMR value of C-4. Therefore mushroom tyrosinase showed stereospecificity in its affinity towards its substrates (Km) but not in the transformation reaction rate (Vmax) of these substrates.

Basidiomycota↗
PubMed2002

Mycelial growth and exo-biopolymer production by submerged culture of various edible mushrooms under different media.

AIMS: The effect of synthetic media on the submerged mycelial growth and exo-biopolymer production in various edible mushrooms was investigated in shake flask culture. METHODS AND RESULTS: Among 19 mushrooms examined, the relatively high yield in mycelial biomass and exo-biopolymer production was achieved in potato malt peptone (PMP) medium. In particular, Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 showed favourable growth in PMP medium with exo-biopolymer concentration of 1170 and 1520 mg l(-1), respectively. CONCLUSIONS: Enhanced exo-biopolymer production was achieved from Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 in a 5L batch fermentor, indicating approximately 5000 and 2410 mg l(-1), respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The exo-biopolymer production and mycelial growth from various mushrooms were found to be strongly controlled by different complex media.

Agaricales↗
PubMed2000

Clitocypin, a new type of cysteine proteinase inhibitor from fruit bodies of mushroom clitocybe nebularis.

A novel inhibitor of cysteine proteinases has been isolated from fruit bodies of a mushroom Clitocybe nebularis. The inhibitor was purified to homogeneity by affinity chromatography and gel filtration, followed by reverse-phase high pressure liquid chromatography. The active inhibitor has an apparent molecular mass of about 34 kDa by gel filtration and by SDS-polyacrylamide gel electrophoresis without prior boiling of the sample. Boiling in 2.5% SDS or incubation in 6 m guanidine hydrochloride resulted in a single band of 17 kDa, indicating homodimer composition with no intersubunit disulfide bonds. The inhibitor in nondenaturing buffer is resistant to boiling in water, retaining its activity and dimer composition. The mushroom protein is a tight binding inhibitor of papain (K(i) = 0.59 nm), cathepsin L (K(i) = 0.41 nm), cathepsin B (K(i) = 0.48 micrometer), and bromelain (K(i) = 0.16 micrometer) but is inactive toward cathepsin H, trypsin, and pepsin. Its isoelectric point is 4.4, and sugar analysis indicates the absence of carbohydrate. A single protein sequence of 150 amino acids, containing no cysteine or methionine residues, was obtained by amino acid sequencing. The calculated molecular mass of 16854 Da corresponds well with the value obtained by mass spectrometry. A major part of this sequence was verified by molecular cloning. The monomer sequence is clearly devoid of typical cystatin structure elements and has no similarity to any other known cysteine proteinase inhibitors but bears some similarity to a lectin-like family of proteins from mushrooms. The inhibitor, which is present in at least two other members of the Clitocybe genus, has been named clitocypin (Clitocybe cysteine proteinase inhibitor).

Agaricus↗
PubMed2002

Several pseudomonads, associated with the cultivated mushrooms Agaricus bisporus or Pleurotus sp., are hemolytic.

Pseudomonas tolaasii, causing brown blotch disease on cultivated mushrooms, and yielding a white line precipitate towards P. "reactans", has been shown to induce lysis of erythrocytes. Some Finnish strains isolated from diseased mushroom fruit bodies, although harboring the typical features of P. tolaasii, proved to be distinct, and have been allocated to a nov. sp. P. costantinii. We examined in these study whether all brown blotch causing agents were hemolytic. The induction of erythrocytes lysis seemed to be a rather common feature of mushroom associated-pseudomonads, especially for strains involved in the production of a white-line-in agar.

Agaricus↗
PubMed2006

Residue evaluation of famoxadone and trifloxystrobin in cultivated mushrooms.

Dissipation of the fungicides famoxadone and trifloxystrobin in basidiocarps of Agaricus bisporus was studied in mushroom growing rooms. The mushroom samples taken at all three consecutive production flushes following single or split applications of the fungicides were extracted with solvents and the residues were determined by using a gas chromatograph equipped with an electron capture detector (GC-ECD). Recoveries from the fortified control samples ranged from 87 to 105%. Following drench applications at 0.1-1 g/m2 of culture bed area, the highest famoxadone residue determined in basidiocarps was 0.1447 mg/kg. Analysis of trifloxystrobin revealed a quantitative relationship between the application rate (0.8-1.8 g/m2) and the residue levels of both the parent compound and its acid metabolite. The maximal combined residues of trifloxystrobin and its metabolite were 0.1313 mg/kg. Short- and long-term dietary risk assessment for both fungicides was carried out using consumption data from World Health Organization and the UK Pesticide Safety Directorate's Ten Consumer Model. The potential acute and chronic residue intakes via mushroom consumption were below toxicologically significant indicators.

Acetates↗
PubMed2006

Elemental distribution in selected Agaricus and Rhizina mushrooms in South Africa.

The levels of calcium, magnesium, iron, manganese, lead, chromium and cadmium in four prevalent mushroom species in South Africa, namely two edible Agaricus bisporus species, one inedible Agaricus xanthodermus species and a poisonous type mushroom, Rezhina undulata are reported. Analytical results from the open vessel and microwave digestion approaches were compared. While higher levels of Ca and Mg were found in the edible types, the inedible and poisonous type mushrooms had relatively high levels of manganese, chromium, cadmium and lead. Agaricus xanthodermus had Ca (204), Mg (660), Fe (306), Mn (30), Cr (16.2), Pb (50.6) and Cd (29.5) mg kg(-1) by dry weight, while Rhizina undulata, which grows on dead wood recorded Ca (121), Mg (517), Fe (130), Mn (30.7), Cr (32.1), Pb (49.5) and Cd (20) mg kg(-1) by dry weight.

Agaricus↗
PubMedDate not supplied

Hepatocarcinogenesis by hydrazine mycotoxins of edible mushrooms.

Two edible mushrooms are known to contain hydrazine analogs. The wild false morel Gyromitra esculenta contains up to 0.3% acetaldehyde methylformylhydrazone and N-methyl-N-formylhydrazine (MFH). The latter chemical, under certain conditions, also yields methylhydrazine. The commonly eaten, cultivated mushroom Agaricus bisporus contains up to 0.04% beta-N-[gamma-L(+)-glutamyl]-4-hydroxymethylphenylhydrazine and 4-hydroxymethylphenylhydrazine. MFH was administered in drinking water continuously for life to Swiss mice and Syrian (golden) hamsters. In both species the compound induced high incidences of benign and malignant hepatocellular neoplasms. Also, methylhydrazine given orally induced a significant incidence of malignant histiocytomas in the livers of hamsters. The N'-acetyl derivative of 4-hydroxymethylphenylhydrazine administered orally to mice gave rise to lung tumors and blood vessel tumors, mainly in the liver. Furthermore, these three compounds produced tumors in various other tissues. Histopathologically, the tumors were classified as benign hepatomas, liver cell carcinomas, angiomas and angiosarcomas of blood vessels, and adenomas and adenocarcinomas of lungs. From representative samples of these neoplasms detailed transmission electron microscopic investigations were also carried out. Since these hydrazine analogs induce tumors in animals and these mushrooms are consumed on a large scale by humans in various parts of the world, their hazardous nature should be considered.

Animals↗
PubMed2002

Mercury in mushrooms and soil of the Tarnobrzeska Plain, south-eastern Poland.

Mercury was quantified in the fruiting bodies of 15 species of higher mushrooms and underlying soil substrate collected from the Tarnobrzeska Plain in south-eastern part of Poland in 1995. In total, 405 samples each of caps, stalks or whole fruiting bodies and 221 samples of soil (0 10cm layer) were examined. The area under investigation can be considered generally as unpolluted with mercury since the mean concentrations in underlying soil substrate of 14 mushroom species were between 21 +/- 9 and 58 +/- 31 ng/g dry wt. (total range between 4.5-240). Somewhat elevated concentrations, of 630 +/- 80 ng/g dry wt., were noted for underlying soil substrate of Livid Entoloma (Entoloma sinuatum). Among the mushroom species examined, King Bolete (Boletus edulis), Livid Entoloma, and Red-capped Scaber Stalk (Leccinum rufum) contained the greatest mercury concentrations both in the caps (between 1,800 +/- 600 and 3,500 +/- 1,100 ng/g dry wt.) and stalks (between 900 +/- 400 and 2,300 +/- 1,000 ng/g dry wt.). Because of the relatively great bioconcentration factors (BCF) of mercury, which averaged between 73 +/- 44 and 220 +/- 270 in the caps, and between 37 +/- 28 and 170 +/- 240 in the stalks, King Bolete, Bay Bolete (Xerocomus badius) and Red-capped Scaber Stalk can be considered as good mercury accumulators. Nevertheless, apart from the Common Earth Ball (Scleroderma citrinum), that can be considered as an excluder of mercury due to the BCF value of less than 1, other species examined were characterised by BCFs greater than 1. The caps were usually characterised with greater mercury content than the stalks (Hg(Cap)/Hg(stalk) quotients > 1) and the reverse was noted only for Bay Bolete. Due to a statistically significant relationship between mercury content of the caps/stalks and underlying soil substrate (p<0.001) in Filamentous Pax (Paxilus filamentosus), and in the stalks of Red-capped Scaber (p < 0.05) and Brick Tops (Hypholoma sublateritium) (caps; p < 0.05), these species can be suggested to exhibit bioindication potential for soil mercury contamination.

Agaricales↗
PubMed2005

The pharmacological potential of mushrooms.

This review describes pharmacologically active compounds from mushrooms. Compounds and complex substances with antimicrobial, antiviral, antitumor, antiallergic, immunomodulating, anti-inflammatory, antiatherogenic, hypoglycemic, hepatoprotective and central activities are covered, focusing on the review of recent literature. The production of mushrooms or mushroom compounds is discussed briefly.

Journal Article↗
PubMed2001

White button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation.

Estrogen is a major factor in the development of breast cancer. In situ estrogen production by aromatase/estrogen synthetase in breast cancer plays a dominant role in tumor proliferation. Because natural compounds such as flavones and isoflavones have been shown to be inhibitors of aromatase, it is thought that vegetables that contain these phytochemicals can inhibit aromatase activity and suppress breast cancer cell proliferation. Heat-stable extracts were prepared from vegetables and screened for their ability to inhibit aromatase activity in a human placental microsome assay. The white button mushroom (species Agaricus bisporus) suppressed aromatase activity dose dependently. Enzyme kinetics demonstrated mixed inhibition, suggesting the presence of multiple inhibitors or more than one inhibitory mechanism. "In cell" aromatase activity and cell proliferation were measured using MCF-7aro, an aromatase-transfected breast cancer cell line. Phytochemicals in the mushroom aqueous extract inhibited aromatase activity and proliferation of MCF-7aro cells. These results suggest that diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen.

Agaricus↗
PubMed2003

Various selected vegetables, fruits, mushrooms and red wine residue inhibit bone resorption in rats.

To make a broad survey of the effect of components of the human diet on bone resorption, a few items from the following categories were added to rat diets: vegetables, fruits, beans, nuts and seeds, mushrooms, carbohydrate sources and beverages. The effect on bone resorption was measured by the urinary excretion of tritium released from bones of 9-wk-old rats prelabeled with tritiated tetracycline from weeks 1 to 6. The number of rats per experiment was 26--6, 5, 5, 5 and 5 in the untreated control group fed the plain semipurified diet, the positive control group fed onions and three groups fed one of the newly investigated items, respectively. New experiments were added until 10 rats were fed each item in each of two separate experiments. The results for each item were compared to those for the untreated control group (n = 12) investigated simultaneously. We found that feeding rats 1 g/d of dry fennel, celeriac, oranges, prunes, French beans and farmed and wild mushrooms (Agaricus hortensis and Boletus edulis) as well as the freeze-dried residue from red wine significantly (P < 0.05 or lower) inhibited bone resorption. Eighteen items had no significant effect. To date we have found 25/53 items that exhibit inhibitory activity. Activity appears to be restricted to the following categories: vegetables, salads, herbs, mushrooms, fruits and red wine residue (25/36 items effective). Furthermore, as assessed in a similar experimental design with various doses of a mixture of active items, we determined the minimum effective dose of the dry items to be 170 mg/d. These results open the possibility for targeted interventions in humans.

Agaricales↗
PubMed1996

Phylogenetic evidence for horizontal transmission of group I introns in the nuclear ribosomal DNA of mushroom-forming fungi.

Group I introns were discovered inserted at the same position in the nuclear small-subunit ribosomal DNA (nuc-ssu-rDNA) in several species of homobasidiomycetes (mushroom-forming fungi). Based on conserved intron sequences, a pair of intron-specific primers was designed for PCR amplification and sequencing of intron-containing rDNA repeats. Using the intron-specific primers together with flanking rDNA primers, a PCR assay was conducted to determine presence or absence of introns in 39 species of homobasidiomycetes. Introns were confined to the genera Panellus, Clavicorona, and Lentinellus. Phylogenetic analyses of nuc-ssu-rDNA and mitochondrial ssu-rDNA sequences suggest that Clavicorona and Lentinellus are closely related, but that Panellus is not closely related to these. The simplest explanation for the distribution of the introns is that they have been twice independently gained via horizontal transmission, once on the lineage leading to Panellus, and once on the lineage leading to Lentinellus and Clavicorona. BLAST searches using the introns from Panellus and Lentinellus as query sequences retrieved 16 other similar group I introns of nuc-ssu-rDNA and nuclear large-subunit rDNA (nuc-lsu-rDNA) from fungal and green algal hosts. Phylogenetic analyses of intron sequences suggest that the mushroom introns are monophyletic, and are nested within a clade that contains four other introns that insert at the same position as the mushroom introns, two from different groups of fungi and two from green algae. The distribution of host lineages and insertion sites among the introns suggests that horizontal and vertical transmission, homing, and transposition have been factors in intron evolution. As distinctive, heritable features of nuclear rDNAs in certain lineages, group I introns have promise as phylogenetic markers. Nevertheless, the possibility of horizontal transmission and homing also suggest that their use poses certain pitfalls.

Base Sequence↗
PubMed2001

Screening for selective thrombin inhibitors in mushrooms.

Thrombin is the key serine proteinase of the coagulation cascade and therefore a suitable target for inhibition of blood coagulation. A number of pharmacologically active secondary metabolites from mushrooms have already been isolated, thus providing the rationale for screening for new thrombin inhibitors in mushrooms. In this study, inhibitory activities of mushroom extracts on thrombin and trypsin were measured using the chromogenic substrates H-D-phenylalanine-L-pipecolyl-L-arginine-paranitroaniline dihydrochloride (S-2238) for thrombin and N-benzoyl-D,L-Arg-p-nitroanilide (BAPNA) for trypsin. The inhibitory activities of extracts from 95 Basidiomycete species have been determined. The majority of samples inhibited trypsin and thrombin with various potencies; however, some extracts showed no activity against one or both of the enzymes. An aqueous extract of Gleophyllum odoratum exhibited high inhibitory activity on both thrombin and trypsin (72 and 60%, respectively), while extracts of Clitocybe gibba, Amanita virosa, Cantharellus lutescens, Suillus tridentinus, Hypoloma fasciculare and Lactarius badiosanguineus considerably inhibited thrombin (49, 48, 36, 34, 32 and 31%, respectively) and showed no inhibitory activity on trypsin. The results at this point are promising for further research with the objective of finding an effective and safe thrombin inhibitor.

Agaricales↗
PubMed1998

Nitric oxide compartments in the mushroom bodies of the locust brain.

All insect brains contain mushroom-shaped neural bodies which are implicated in associative learning. Here we show that the mushroom bodies of the locust brain have a remarkable and hitherto undescribed neural organisation consisting of six tubular structures in which bundles of axons are enclosed by cylindrical walls of nitric oxide synthase (NOS) expressing processes. A dynamic temporo-spatial simulation shows that the tubular organization allows NO to attain and maintain locally elevated concentrations within highly structured domains in the CNS. A diffusible gaseous signalling molecule such as NO can therefore selectively affect computational processes occurring in discrete parallel channels of information flow in the brain. The implications of this are discussed in relation to the role of NO in a compartmental model of the mushroom bodies and more generally in the context of the targetting of diffusible messenger molecules in the brain.

Animals↗