Insights into health promoting effects and myochemical profiles of pine mushroom Tricholoma matsutake.

Tricholoma matsutake (TM) is a valuable edible mushroom that has attracted increasing attention due to its potential medicinal values and functional uses. However, the chemical composition and molecular mechanisms behinds TM are not specifically summarized yet. Hence, this review aims to systematically analyze the research progress on the characterization of chemical compositions and the reported health effects of TM in the last 20 years. The myochemical profiles of TM consist of proteins with amino acids, fatty acids, nucleic acids with their derivatives, polysaccharides, minerals, volatile components, phenolic compounds, and steroids. The bioactive substances in TM exert their health effects mainly by regulating body immunity and restoring the balance of the redox system. NF-κB signaling pathway and its downstream cytokines such as TNF-α and IL-6 are the key molecular mechanisms. In addition, MAPK, PI3K-Akt, and JAK-STAT are also involved. NF-κB, MAPK, and PI3K-Akt are also highly related to cancer regulation and thus TM has great anticancer potential. Considering that most studies have only investigated the dosage and inhibition rate of TM on cancer cell lines, more extensive studies need to focus on the specific molecular mechanisms behind these anticancer effects in the future.

Tricholosterols A-D, four new ergosterol derivatives from the mushroom Tricholoma terreum.

Four ergosterol derivatives, named tricholosterols A-D (1-4), have been isolated from the fruiting bodies of Tricholoma terreum. Their chemical structures have been determined using a combination of spectroscopic analysis as well as computational methods. Compound 1 possesses a rare D-ring opening ergosterol skeleton, while compounds 2-4 are rare degraded ergosterols. Compounds 1 and 4 exhibited moderate inhibitory activity against NO production with IC50 values of 27.6 and 31.8 µM, respectively. This is the first report of steroids from T. terreum.

Contamination, bioconcentration and distribution of mercury in Tricholoma spp. mushrooms from southern and northern regions of Europe.

The contamination, bio-concentration and distribution of mercury (Hg) in wild mushrooms of the genus Tricholoma such as T. equestre, T. portentosum, T. columbeta, and T. terreum were studied, and the possible dietary intake and risk for human consumers in Europe was estimated. Mushrooms, together with the associated forest topsoils were collected from 10 unpolluted and geographically distant areas, far from local or regional emission sources, in Poland (2 sites) and Croatia (8 sites). The Hg contents were in the range 0.10 ± 0.06 to 0.71 ± 0.34 mg kg-1 dry matter in caps and 0.04 ± 0.02 to 0.38 ± 0.13 mg kg-1 in stems. The corresponding topsoil concentrations varied over a relatively narrow range between sites, from 0.013 ± 0.003 to 0.028 ± 0.006 mg kg-1 dry matter. Overall, the study results showed low levels of mercury both, in edible Tricholoma mushrooms and forest topsoils from background (unpolluted) forested areas in Croatia and Poland. The morphological distribution showed considerably greater concentrations of mercury in the caps relative to the stems with ratios ranging from 1.6 ± 0.6 to 3.9 ± 1.8. T. equestre showed good ability to bioconcentrate Hg, with bioconcentration factors (BCF) values in the range 18 ± 7 to 37 ± 18. The data suggests that Tricholoma mushrooms from unpolluted areas in southern and northern regions of Europe can be considered as a low risk food from the point of view of the tolerable Hg intake.

Tricholopardins A and B, Anti-inflammatory Terpenoids from the Fruiting Bodies of Tricholoma pardinum.

Two new Tricholoma terpenoids, tricholopardins A and B, were isolated from the fruiting bodies of the basidiomycetes Tricholoma pardinum. Their structures were elucidated by spectroscopic methods, as well as electronic circular dichroism and optical rotatory dispersion calculations. Tricholopardin A potently inhibited nitric oxide production in lipopolysaccharide-induced RAW264.7 macrophages with an IC50 of 0.08 µM. Its anti-inflammatory effects on three inflammatory mediators were also evaluated. A plausible biosynthetic pathway for these products is discussed.

Tricholoma matsutake may take more nitrogen in the organic form than other ectomycorrhizal fungi for its sporocarp development: the isotopic evidence.

Tricholoma matsutake is an ectomycorrhizal (ECM) fungus capable of in vitro saprotrophic growth, but the sources of C and N used to generate sporocarps in vivo are not well understood. We examined natural abundance isotope data to investigate this phenomenon. For this purpose, C, N and their stable isotopes (13C, 15N) content of fungal sporocarps and their potential nutrient sources (i.e., foliage, litter, fine roots, wood, and soil) were investigated from two well-studied sites in Finland and Japan. Our results show that δ13C values of T. matsutake and other fungal groups are consistent with those of most studies, but a very high δ15N value (16.8‰ ± 2.3) is observed in T. matsutake. Such isotopic pattern of fungal δ15N suggests that matsutake has a greater proteolytic potential to digest chemically complex 15N-enriched organic matter and hydrophobic hyphae. This assumption is further supported by a significant and positive correlation between δ13Ccap-stipe and δ15Ncap-stipe exclusively in T. matsutake, which suggests common C and N sources (protein) possible for isotopically enriched cap. The 13C increase of caps relative to stipe presumably reflects greater contents of 13C-enriched protein than 13C-depleted chitin. We conclude that T. matsutake is a typical ECM fungus which obtains for its sporocarp development for both C and N from a common protein source (vs. photosynthetic carbon) present in soil organic matter.

A Tricholoma matsutake Peptide with Angiotensin Converting Enzyme Inhibitory and Antioxidative Activities and Antihypertensive Effects in Spontaneously Hypertensive Rats.

Hypertension is a major risk factor for cardiovascular disease. A crude water extract of the fruiting bodies of a highly prized mushroom Tricholoma matsutakei exerted an antihypertensive action on spontaneously hypertensive rats (SHRs) at a dosage of 400 mg/kg. An angiotensin converting enzyme (ACE) inhibitory peptide with an IC50 of 0.40 µM was purified from the extract and designated as TMP. Its amino acid sequence was elucidated to be WALKGYK through LC-MS/MS analysis. The Lineweaver-Burk plot suggested that TMP was a non-competitive inhibitor of ACE. A short-term assay of antihypertensive activity demonstrated that TMP at the dosage of 25 mg/kg could significantly lower the systolic blood pressure (SBP) of SHRs. TMP exhibited remarkable stability over a wide range of temperatures and pH values. It also demonstrated 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The aforementioned activities of TMP were corroborated by utilizing the synthetic peptide. Hence T. matsutake can be used as a functional food to help prevent hypertension- associated diseases.

Comment on "Chemical and Toxicological Investigations of a Previously Unknown Poisonous European Mushroom Tricholoma terreum".

Recent findings casting doubts over the edibility of the European mushroom Tricholoma terreum are questioned on the basis of mycological and mycotoxicological considerations. Accordingly, T. terreum should remain listed among edible mushroom species.

Response to the "Comment on Chemical and Toxicological Investigations of a Previously Unknown Poisonous European Mushroom Tricholoma terreum".

Recently, Dr. Paolo Davoli and his colleagues stated that the conclusions drawn by us were misleading from a mycotoxicological perspective, as they cast doubts on the edibility of a mushroom species (Tricholoma terreum) that has been always recognized as safe. Unfortunately, they made a mistake, and seriously misinterpreted our data, which resulted in scepticism of our research. Saponaceolides B and M were tested for their stabilities heating directly on and boiling in water. It is undoubted that both saponaceolides B and M are capable of withstanding prolonged heating during cooking.

Optimization of cellulase-assisted extraction process and antioxidant activities of polysaccharides from Tricholoma mongolicum Imai.

BACKGROUND: Tricholoma mongolicum Imai is a well-known edible and medicinal mushroom which in recent years has attracted increasing attention because of its bioactivities. In this study, water-soluble polysaccharides were extracted from T. mongolicum Imai by cellulase-assisted extraction and their antioxidant activities were investigated. RESULTS: In order to improve the yield of polysaccharides, four variables, cellulase amount (X1 ), pH (X2 ), temperature (X3 ) and extraction time (X4 ), were investigated with a Box-Behnken design. The optimal conditions were predicted to be cellulase amount of 20 g kg(-1) , pH of 4.0, temperature of 50 °C and extraction time of 127 min, with a predicted polysaccharide yield of 190.1 g kg(-1) . The actual yield of polysaccharides under these conditions was 189.6 g kg(-1) , which matched the predicted value well. The crude polysaccharides were purified to obtain four fractions, and characterization of each was carried out. In addition, antioxidant properties of four polysaccharides assessed by 1,1-diphenyl-2-picryldydrazyl (DPPH) and hydroxyl radical-scavenging assays indicated that polysaccharides from T. mongolicum Imai (TMIPs) possessed antioxidant activity in a dose-dependent manner. CONCLUSION: TMIPs show moderate antioxidant activities in vitro. Therefore it is suggested that TMIPs are potential natural antioxidants for use in functional foods. © 2016 Society of Chemical Industry.

Influence of zygomycete-derived D'orenone on IAA signalling in Tricholoma-spruce ectomycorrhiza.

Despite the rising interest in microbial communication, only few studies relate to mycorrhization and the pool of potential morphogenic substances produced by the surrounding soil community. Here, we investigated the effect exerted by the C18 - ketone ß-apo-13-carotenone, D'orenone, on the ectomycorrhizal basidiomycete Tricholoma vaccinum and its symbiosis with the economically important host tree, spruce (Picea abies). D'orenone is an early intermediate in the biosynthesis of morphogens in sexual development of mucoromycetes, the trisporoids. In the ectomycorrhizal fungus T. vaccinum, D'orenone increased the production and/or release of the phytohormone indole-3-acetic acid (IAA) which had been proposed to be involved in the mutual symbiosis. The induced expression of the fungal aldehyde dehydrogenase, Ald5 is associated with IAA synthesis and excretion. In the host tree, D'orenone modulated root architecture by increasing lateral root length and hypertrophy of root cortex cells, likely via changed IAA concentrations and flux. Thus, we report for the first time on carotenoid metabolites from soil fungi affecting both ectomycorrhizal partners. The data imply a complex network of functions for secondary metabolites which act in an inter-kingdom signalling in soil.

Biosynthesis and Secretion of Indole-3-Acetic Acid and Its Morphological Effects on Tricholoma vaccinum-Spruce Ectomycorrhiza.

Fungus-derived indole-3-acetic acid (IAA), which is involved in development of ectomycorrhiza, affects both partners, i.e., the tree and the fungus. The biosynthesis pathway, excretion from fungal hyphae, the induction of branching in fungal cultures, and enhanced Hartig net formation in mycorrhiza were shown. Gene expression studies, incorporation of labeled compounds into IAA, heterologous expression of a transporter, and bioinformatics were applied to study the effect of IAA on fungal morphogenesis and on ectomycorrhiza. Tricholoma vaccinum produces IAA from tryptophan via indole-3-pyruvate, with the last step of this biosynthetic pathway being catalyzed by an aldehyde dehydrogenase. The gene ald1 was found to be highly expressed in ectomycorrhiza and induced by indole-3-acetaldehyde. The export of IAA from fungal cells is supported by the multidrug and toxic extrusion (MATE) transporter Mte1 found in T. vaccinum. The addition of IAA and its precursors induced elongated cells and hyphal ramification of mycorrhizal fungi; in contrast, in saprobic fungi such as Schizophyllum commune, IAA did not induce morphogenetic changes. Mycorrhiza responded by increasing its Hartig net formation. The IAA of fungal origin acts as a diffusible signal, influencing root colonization and increasing Hartig net formation in ectomycorrhiza.

Lead-resistant strain KQBT-3 inoculants of Tricholoma lobayensis Heim that enhance remediation of lead-contaminated soil.

To enhance lead-detoxifying efficiency of Tricholoma lobayensis Heim, one lead-resistant strain KQBT-3 (Bacillus thuringiensis) was applied owing to its excellent ability to tolerate Pb. KQBT-3 domesticated in liquid medium with increasing lead concentrations could tolerate Pb(NO3)2 up to a concentration of 800 mg L(-1). Pot experiments showed that the KQBT-3 not only could promote the growth of T. lobayensis, but also could enhance its Pb accumulation ability under heavy metal stress. Biomass and accumulation of Pb increased 47.3% and 33.2%, respectively. In addition, after inoculation of KQBT-3, the significant decrease of malondialdehyde indicated KQBT-3 could alleviate lipid peroxidation in T. lobayensis. What is interesting is that superoxide dismutase and peroxidase activities in T. lobayensis inoculated with KQBT-3 were increased, and the maximum increasing rate was 121.71% and 117.29%, respectively. However, the catalase activity increased slightly. This revealed that inoculating KQBT-3 further induced oxidative response in T. lobayensis due to Pb accumulation. Therefore, the present work showed that KQBT-3 made a major contribution to promote growth and lead uptake of T. lobayensis and alleviate the oxidative stress. This kind of auxiliary effect on macrofungi can be developed into a novel bioremediation strategy.

Tricholoma matsutake fruit bodies secrete hydrogen peroxide as a potent inhibitor of fungal growth.

Tricholoma matsutake is an ectomycorrhizal fungus that dominates the microbial communities in the soil of pine and spruce forests. The mycorrhizas of this fungus have antimicrobial activity, although factors responsible for the antimicrobial activity have not been fully elucidated. The present study shows that fruit bodies of T. matsutake secreted hydrogen peroxide (H2O2), which was produced by pyranose oxidase, and that the H2O2 thus secreted strongly inhibited the growth of mycelia of the phytopathological fungus Rhizoctonia solani. These findings suggest that fruit bodies of T. matsutake have antifungal activity and that the pyranose oxidase plays an important role in the antifungal activity.

A transporter for abiotic stress and plant metabolite resistance in the ectomycorrhizal fungus Tricholoma vaccinum.

Fungi exposed to toxic substances including heavy metals, xenobiotics, or secondary metabolites formed by co-occurring plants or other microorganisms require a detoxification system provided by exporters of several classes of transmembrane proteins. In case of mycorrhiza, plant metabolites need to be exported at the plant interface, while the extraradical hyphae may prevent heavy metal uptake, thus acting as a biofilter to the host plant at high environmental concentrations. One major family of such transporter proteins is the multidrug and toxic compound extrusion (MATE) class, a member of which, Mte1, was studied in the ectomycorrhizal fungus Tricholoma vaccinum. Phylogenetic analyses placed the protein in a subgroup of basidiomycete MATE sequences. The gene mte1 was found to be induced during symbiotic interaction. It mediated detoxification of xenobiotics and metal ions such as Cu, Li, Al, and Ni, as well as secondary plant metabolites if heterologously expressed in Saccharomyces cerevisiae.

Tricholoma matsutake can absorb and accumulate trace elements directly from rock fragments in the shiro.

Tricholoma matsutake, a highly valued delicacy in Japan and East Asia, is an ectomycorrhizal fungus typically found in a complex soil community of mycorrhizae, soil microbes, and host-tree roots referred to as the shiro in Japan. A curious characteristic of the shiro is an assortment of small rock fragments that have been implicated as a direct source of minerals and trace elements for the fungus. In this study, we measured the mineral content of 14 samples of shiro soil containing live matsutake mycelium and the extent to which the fungus can absorb minerals directly from the rock fragments. X-ray powder diffraction identified major phases of quartz, microcline, orthoclase, and albite in all shiro samples. PCR-denaturing gradient gel electrophoresis (DGGE) fingerprinting and direct sequencing confirmed the presence of T. matsutake on 32 of 33 rock fragments. Piloderma sp. co-occurred on 40% of fragments and was positively correlated with locations known to produce good mushroom crops. The ability of T. matsutake to absorb trace elements directly from rock fragments was examined in vitro on nutrient-agar plates supplemented with rock fragments from the shiro. In comparison to the mineral content of tissues grown on control media, the concentration of Al, Cu, Fe, Mn, P, and Zn increased from 1.1 to 106.4 times for both T. matsutake and Piloderma sp. Mineral content of dried sporocarps sampled from the study site partially reflected the results of the in vitro study. We discuss the implications of our results with respect to the natural development and artificial culture of this important fungus.

Chemical and toxicological investigations of a previously unknown poisonous European mushroom Tricholoma terreum.

The established tradition of consuming and marketing wild mushrooms has focused attention on mycotoxicity, which has become a global issue. In the present study, we describe the toxins found in a previously unknown poisonous European mushroom Tricholoma terreum. Fifteen new triterpenoids terreolides A-F (1-6) and saponaceolides H-P (8-16) were isolated from the fruiting bodies of the toxic mushroom T. terreum. Terreolides A-C (1-3) possessed a unique 5/6/7 trioxaspiroketal system, whereas terreolides D-F (4-6) possessed an unprecedented carbon skeleton. Two abundant compounds in the mushroom, saponaceolide B (7) and saponaceolide M (13), displayed acute toxicity, with LD50 values of 88.3 and 63.7 mg kg(-1) when administered orally in mice. Both compounds were found to increase serum creatine kinase levels in mice, indicating that T. terreum may be the cause of mushroom poisoning ultimately leading to rhabdomyolysis.

Effect of heavy metal-solubilizing microorganisms on zinc and cadmium extractions from heavy metal contaminated soil with Tricholoma lobynsis.

The macrofungus, Tricholoma lobynsis, was chosen to remedy Zn-Cd-Pb contaminated soil. To enhance its metal-extracting efficiency, two heavy metal resistant microbes M6 and K1 were applied owing to their excellent abilities to solubilize heavy metal salts. The two isolated microbial strains could also produce indole acetic acid (IAA), siderophore and solubilize inorganic phosphate, but neither of them showed 1-aminocyclopropane-1-carboxylate deaminase activity. The strains M6 and K1 were identified as Serratia marcescens and Rhodotorula mucilaginosa based on 16S rDNA and ITS sequence analysis respectively. Pot experiment showed that spraying to T. lobynsis-inoculated soil with M6 and K1 respectively could increase total Cd accumulations of this mushroom by 216 and 61%, and Zn by 153 and 49% compared to the uninoculated control. Pb accumulation however, was too low (<1 mg kg(-1)) to be determined. The results illustrated that special microbes and macrofungi can work together to remedy polluted soil as plant and plant growth promoting microbes do, probably because of excellent metal-accumulating abilities of macrofungi and IAA-siderophore production, phosphate solubilization abilities of the assisted-microbes. This kind of macrofungi-microbe interaction can be developed into a novel bioremediation strategy.

Toward the antioxidant and chemical characterization of mycorrhizal mushrooms from northeast Portugal.

UNLABELLED: Mushrooms are widely appreciated all over the world for their nutritional properties and pharmacological value as sources of important bioactive compounds. Mycorrhizal macrofungi associate with plant roots constituting a symbiotic relationship. This symbiosis could influence the production of secondary metabolites, including bioactive compounds. We focused on the evaluation of antioxidant potential and chemical composition of mycorrhizal mushrooms species from Northeast Portugal: Amanita caesarea, Amanita muscaria, Amanita pantherina, Chroogomphus fulmineus, Cortinarius anomalus, Cortinarius collinitus, Cortinarius violaceus, Lactarius quietus, Lactarius volemus, Russula sardonia, Suillus luteus, and Tricholoma ustale. A similar profile of metabolites was observed in the studied species with the order sugars > fat > ascorbic acid > phenolic compounds > tocopherols. Nevertheless, the samples revealed different compositions: prevalence of sugars in L. volemus, fat and ascorbic acid in A. muscaria, phenolic compounds in C. anomalus and tocopherols, and antioxidant activity in S. luteus. PRACTICAL APPLICATION: Chemical characterization of 12 mycorrhizal mushrooms was achieved. They are sources of nutraceuticals, such as sugars and fatty acids, and contain bioactive compounds, such as vitamins and phenolic acids. Edible species can be incorporated in diets as sources of antioxidants, while nonedible species can be explored as sources of bioactive metabolites.

Process development for mycelial growth and polysaccharide production in Tricholoma matsutake liquid culture.

In this study, the effects of agitation and aeration on mycelial growth and exo-polysaccharide production were examined in batch cultures of Tricholoma matsutake. Agitation was varied from 100 to 300 rpm and aeration was varied from 0.5 to 1.5 vvm. Mycelial growth was 21.87 g/l at 150 rpm, and exo-polysaccharide production was 8.79 g/l at 1.5 vvm. When we analyzed the polysaccharide extractions from the cultured mycelium and the culture broth of T. matsutake, 1.4 g of crude polysaccharide was found per 100 g of dried weight in the cultured mycelium, and 1.47 g/l of polysaccharides was found in the culture broth. In addition, the amounts of beta-Glucan in the soluble polysaccharide fractions of the cultured mycelium and culture broth were 75.4% and 83.6%, respectively. The cultured mycelium and the culture broth contained a higher amount of beta-Glucan than that of the fruiting body.

Tracing metabolic pathways of lipid biosynthesis in ectomycorrhizal fungi from position-specific 13C-labelling in glucose.

Six position-specific (13)C-labelled isotopomers of glucose were supplied to the ectomycorrhizal fungi Suillus pungens and Tricholoma flavovirens. From the resulting distribution of (13)C among fungal PLFAs, the overall order and contribution of each glucose atom to fatty acid (13)C enrichment was: C6 (approximately 31%) > C5 (approximately 25%) > C1 (approximately 18%) > C2 (approximately 18%) > C3 (approximately 8%) > C4 (approximately 1%). These data were used to parameterize a metabolic model of the relative fluxes from glucose degradation to lipid synthesis. Our data revealed that a higher amount of carbon is directed to glycolysis than to the oxidative pentose phosphate pathway (60% and 40% respectively) and that a significant part flows through these pathways more than once (73%) due to the reversibility of some glycolysis reactions. Surprisingly, 95% of carbon cycled through glyoxylate prior to incorporation into lipids, possibly to consume the excess of acetyl-CoA produced during fatty acid turnover. Our approach provides a rigorous framework for analysing lipid biosynthesis in fungi. In addition, this approach could ultimately improve the interpretation of isotopic patterns at natural abundance in field studies.