Mineral composition variation in Boletales mushrooms-indication of soil properties and taxonomic influence.

The efficiency of element accumulation depends on numerous factors, where the physico-chemical characteristics of the soil seem to be very important, and the role of taxonomic rank in the accumulation of elements by mushrooms seems to be important. The aim of the study was to compare the mineral composition of 7 species belonging to Leccinum and Suillus genera, collected between 2019 and 2021 from localizations in the west-central part of Poland. The research aimed to indicate the role of selected soil parameters in stimulating/inhibiting the accumulation of elements by selected Boletales mushroom species and to answer the question about the role of species belonging to the genus as an indicator determining the specific mineral composition of fruiting bodies. Soil pH and other soil properties (granulometric composition, organic carbon, degree of organic matter decomposition) may significantly affect mushrooms' mineral composition. Mushroom species belonging to Leccinum genus exhibited the higher amount of essential major and trace elements than species of Suillus genus). It suggests that the affiliation of the studied mushroom species to a specific genus may affect their mineral composition, and the physicochemical properties of the soil may be responsible for the lack of a clear division in the efficiency of element(s) accumulation. Selected species contain high amounts of K, Cu, Fe, and Zn, while others, such as selected Suillus gravellei fruiting bodies, also contain As and Cd. The results described serve as an introduction to a broader scientific discussion and require many further studies to confirm the role of taxonomic ranks and the influence of soil characteristics on the accumulation of elements by fruiting bodies.

Can the concentration of elements in wild-growing mushrooms be deduced from the taxonomic rank?

The mineral composition of wild-growing mushroom species is influenced by various environmental factors, particularly the chemical properties of the soil/substrate. We hypothesised that element uptake might also correlate with taxonomic classification, potentially allowing us to predict contamination levels based on mushrooms within the same taxonomic rank. This study compared the mineral composition (Ag, As, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se, and Zn) of 16 saprotrophic mushroom species from 11 genera across 4 families and 2 orders. Among these were 13 edible and 3 inedible mushrooms, all collected from natural, wild stands in a forest in central-western Poland between 2017 and 2020. Phallus impudicus exhibited the highest mean content of Ba (together with Phallus hadriani) (6.63 and 8.61 mg kg-1, respectively), Ca (with Paralepista gilva and Stropharia rugosoannulata) (803, 735 and 768 mg kg-1, respectively), Cd (with Lycoperdon perlatum) (3.59 and 3.12 mg kg-1, respectively), Co (0.635 mg kg-1), and Fe (with P. hadriani and S. rugosoannulata) (476, 427 and 477 mg kg-1, respectively), while Macrolepiota mastoidea showed the highest content of Ag (1.96 mg kg-1), As (with Coprinus comatus) (1.56 and 1.62 mg kg-1, respectively) and Cu (with Macrolepiota procera and Chlorophyllum rhacodes) (192, 175 and 180 mg kg-1, respectively). Comparing the content of the analysed elements in the genera represented by at least two species, a similarity was observed, the same as the mean concentration in soil under these species. Soil characteristics could be a superior factor that overshadows the impact of the mushroom genus on the elements accumulation, obscuring its role as a determinant in this process. The results are not definitive evidence that belonging to a particular taxonomic rank is a prerequisite condition affecting the accumulation of all elements. A closer focus on this issue is needed.

Mycoremediation of Flotation Tailings with Agaricus bisporus.

Due to their enzymatic and bioaccumulation faculties the use of macromycetes for the decontamination of polluted matrices seems reasonable for bioremediation. For this reason, the aim of our study was to evaluate the mycoremediation ability of Agaricus bisporus cultivated on compost mixed with flotation tailings in different quantities (1, 5, 10, 15, and 20% addition). The biomass of the fruit bodies and the content of 51 major and trace elements were determined. Cultivation of A. bisporus in compost moderately polluted with flotation tailings yielded significantly lower (the first flush) and higher (the second flush) biomass of fruit bodies, compared with the control treatment. The presence of toxic trace elements did not cause any visible adverse symptoms for A. bisporus. Increasing the addition of flotation tailings to the compost induced an elevated level of most determined elements. A significant increase in rare earth elements (both flushes) and platinum group elements (first flush only) was observed. The opposite situation was recorded for major essential elements, except for Na and Mg in A. bisporus from the second flush under the most enriched compost (20%). Nevertheless, calculated bioaccumulation factor values showed a selective accumulation capacity-limited for toxic elements (except for Ag, As, and Cd) and the effective accumulation of B, Cu, K, and Se. The obtained results confirmed that A. bisporus can be used for practical application in mycoremediation in the industry although this must be preceded by larger-scale tests. This application seems to be the most favorable for media contaminated with selected elements, whose absorption by fruiting bodies is the most efficient.

Road traffic and abiotic parameters of underlying soils determine the mineral composition and nutritive value of the mushroom Macrolepiota procera (Scop.) Singer.

The effectiveness of accumulating mineral elements by wild-growing mushrooms depends mainly on species, their growth place, and the underlying soil's chemical characteristics. The aim of the study was to determine the effect of road traffic and the role of chemical characteristics of soil on the mineral composition of Macrolepiota procera fruit bodies growing in close proximity to a road and an adjacent forest during a four-year period. The concentrations of the majority elements (mainly Al, Cd, Co, Cr, Cu, Pb, Ti, and Zn) in the soil near the road were significantly higher than those in the forest soil, which was reflected in the fruit bodies which contained a higher amount of these elements. While the accumulation of heavy metals and other elements in the M. procera fruit bodies did not depend on the total soil organic carbon content, the degree of their decomposition determined by the C:N ratio and the individual fractions of organic carbon had a significant influence. Our studies show that soil properties are highly variable in the natural habitats of M. procera, which affects the efficiency of element accumulation. Macrolepiota procera fruit bodies growing in soil with similar chemical properties were characterized by different mineral compositions. Moreover, the obtained results indicate that the fruit bodies of edible M. procera, not only those close to roads but also at a greater distance, may contain significant amounts of toxic As and Cd, which could pose a health risk if consumed. Although most studies describing the mineral composition of M. procera fruit bodies have found no evidence to question the safety of their consumption, this species can effectively accumulate selected elements when growing immediately beside roads or in their close proximity.

Biofortification of Three Cultivated Mushroom Species with Three Iron Salts-Potential for a New Iron-Rich Superfood.

Mushrooms fortified with iron (Fe) can offer a promising alternative to counter the worldwide deficiency problem. However, the factors that may influence the efficiency of fortification have not yet been fully investigated. The aim of this study was to compare the effects of three Fe forms (FeCl3 6H2O, FeSO4 7H2O, or FeHBED) in three concentrations (5, 10, or 50 mM) for three mushroom species (Pleurotus eryngii, P. ostreatus, or Pholiota nameko) on their chemical composition, phenolic compounds, and organic acid production. The most effective metal accumulation of all the investigated species was for the 50 mM addition. FeCl3 6H2O was the most favorable additive for P. eryngii and P. nameko (up to 145 and 185% Fe more than in the control, respectively) and FeHBED for P. ostreatus (up to 108% Fe more than in control). Additionally, P. nameko showed the highest Fe accumulation among studied species (89.2 ± 7.51 mg kg-1 DW). The creation of phenolic acids was generally inhibited by Fe salt supplementation. However, an increasing effect on phenolic acid concentration was observed for P. ostreatus cultivated at 5 mM FeCl3 6H2O and for P. eryngii cultivated at 5 mM FeCl3 6H2O and 5 mM FeSO4 7H2O. In the case of organic acids, a similar situation was observed. For P. ostreatus, FeSO4 7H2O and FeHBED salts increased the formation of the determined organic acids in fruiting bodies. P. eryngii and P. nameko were characterized by a much lower content of organic acids in the systems supplemented with Fe. Based on the obtained results, we recommend starting fortification by preliminarily indicating which form of the element is preferred for the species of interest for supplementation. It also seems that using an additive concentration of 50 mM or higher is most effective.

The effect of light conditions on the content of selected active ingredients in anatomical parts of the oyster mushroom (Pleurotus ostreatus L.).

This study aimed to evaluate the effect of cultivation conditions in the context of light on the retention of selected vitamins, minerals and polyphenols in the stem and cap of the oyster mushroom (Pleurotus ostreatus L.). Additionally, the effect of the retention of bioactive components on the antioxidant activity of mushroom extracts was evaluated, taking into account the morphological part. Oyster mushrooms grown in the light of 200 lux had higher riboflavin content compared to mushrooms exposed to the light of lower intensity. The thiamine content of the mushrooms dropped with decreasing light intensity during cultivation. The content of biologically active compounds was found to be equal in the stem and the cap. In the case of riboflavin, it was shown that its contents in cap fractions, irrespective of the cultivation method, was statistically significantly higher than in stems. The mineral composition of caps and stems differed from each other. No differences in Zn and Cu content between the morphological parts of the mushroom studied were found. However, it was shown that the stems, regardless of the type of light, contained less iron, magnesium and sodium. Thus, it was observed that limited light exposure caused an increase in the content of total polyphenolic compounds, which did not correlate with antioxidant activity. There was no effect of the light on the antioxidant activity of mushrooms. It was also shown that stem extracts had higher antioxidant activity compared to the extracts obtained from the caps. This findings point to the possibility and potentail of use both fraction of mushrooms in the new food products development.

Anthropogenic contamination leads to changes in mineral composition of soil- and tree-growing mushroom species: A case study of urban vs. rural environments and dietary implications.

Because wild-growing edible mushroom species are frequently consumed, a knowledge of their mineral composition is essential. The content of elements in mushrooms and their possible beneficial or harmful effect may be influenced by the human-impacted environment. Thus, the aim of the study was to analyse the mineral composition of the soil, trees, and especially soil- and tree-growing mushroom species collected from within a city and from rural areas. Due to potentially higher pollution in urban areas, we assumed that mushrooms from a city environment will contain higher levels of mineral elements than those from rural areas and that the high content will be attributed to greater contamination of city soils. Significantly higher concentrations of several elements in soils (Ca, Ba, Bi, Hg, Pb, Sb, Sr, W and Zr) and trees (Ag, Bi, Ce, Co, Mn, Mo, Nd, Pr, Ta, Tm and W) were observed from the samples collected in the city. Additionally, significantly higher contents of Ag, Fe, Hg, Mn, Mo, Sr, Y and Zn in soil-growing, and Al, As, Ba, Cr, Fe, Hg, Ni, Pb, Sr, Ta and Zn in tree-growing mushroom species were recorded from the urban area. These differences formed the basis for the observation that the content of elements in urban mushrooms is generally higher than in those from rural areas. However, a higher content of several soil elements does not necessarily mean that there will be a significantly higher content in fruit bodies. There was also no real risk of consuming soil-growing mushroom species collected in recent years from the city, suggesting that this practice may still be continued.

Influence of Iron Addition (Alone or with Calcium) to Elements Biofortification and Antioxidants in Pholiota nameko.

Mushrooms supplementation with iron (Fe) is usually limited, and therefore it would be beneficial to search for other vital elements able to improve the process. The aim of this study was to verify a possible interaction between Fe and calcium (Ca) to estimate the role of the addition of the latter metal to stimulate Fe accumulation in Pholiota nameko. Additionally, an analysis of phenolic compounds and low molecular weight organic acids (LMWOAs) was performed. The increase of Fe concentration in the substrate caused a significantly higher accumulation of this metal in P. nameko. The addition of Ca (5 or 10 mM) stimulated Fe accumulation, just as Fe concentration in the substrate stimulated Ca accumulation, which pointed to a synergism between these metals. The obtained results show that the presence of Fe in the substrate may also promote K, Mg, Mn, Na, P, and S accumulation. In contrast, the addition of Ca stimulates and/or inhibits their content in fruit bodies. The phenolic and organic acids profile was poor. Only gallic, 4-hydroxybenzoic, sinapic and syringic acids (phenolics), as well as citric and succinic acids (LMWOAs), were quantified in some combinations in P. nameko fruiting bodies.

A Possibility to Use Selected Crop Post-Extraction Wastes to Improve the Composition of Cultivated Mushroom Pleurotus citrinopileatus.

A cultivated mushroom species, Pleurotus citrinopileatus, is becoming increasingly popular thanks to its attractive colour and medicinal properties. In this study, P. citrinopileatus was grown in a cultivation medium enriched with wheat bran (WB), thymus post-extraction waste (TPEW) and pumpkin post-extraction waste (PPEW) products. The study showed that the post-extraction wastes are a crucial factor determining the accumulation of minerals, the content/profile of low-molecular-weight organic acids (LMWOAs) and phenolic compounds in fruit bodies, thereby increasing their nutritional value. The use of the waste materials significantly increased LMWOAs contents. The sum of LMWOAs under all cultivation mediums increased, especially quinic, malic and citric acids under the 20% PPEW, 25 and 50% TPEW addition. Total phenolic content, phenolic content, as well as the composition and scavenging effect on DPPH radicals, were strongly dependent on the used substrate. The control variant was poor in phenolic compounds, while the supplementation increased the contents and diversity of these metabolites. In the control, only four phenolic compounds were quantified (chlorogenic, gallic, syringic and vanillic acids), while in the supplemented substrates up to 14 different phenolic compounds (caffeic, chlorogenic, p-coumaric, 2,5-dihydroxybenzoic acid, ferulic, gallic, protocatechuic, salicylic, sinapic, syringic, trans-cinnamic and vanillic acids, catechin and rutin).

Mineral composition of elements in wood-growing mushroom species collected from of two regions of Poland.

The study monitored the content of 55 elements in 21 wood-growing mushroom species collected between 2013 and 2019 from Lower and Upper Silesia in Poland. Only 27 of the elements (Ag, Al, Ba, Ca, Cd, Cu, Fe, In, K, La, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, Pt, Rh, Sr, Ti, Tm, V, Y, Zn, and Zr) were detected in all mushroom species, while others (As, Au, B, Be, Bi, Ce, Co, Cr, Dy, Er, Eu, Ga, Gd, Ge, Hf, Ho, Ir, Li, Lu, Mo, Os, Pb, Rb, Re, Ru, Sb, Sc, Se, Sm, Tb, Te, Th, Tl, Tm, U, and Yb) were below the limit of detection in the fruit bodies of at least one species. Wide ranges for major elements in the whole population of all the mushroom species were as follows: 15.4-470 (Ca), 6580-44,600 (K), 314-2150 (Mg), 38.0-319 (Na), and 1100-15,500 (P) mg kg-1 dm, respectively. The rank sum revealed that M. giganteus fruit bodies were the most enriched with all detectable elements, while A. mellea had the lowest content of the majority of elements. Mushrooms belonging to the Hymenochaetaceae family were characterized as some of the most enriched with the studied elements, while mushrooms of the Fomitopsidaceae family had the lowest content of elements. Similarities as well as differences between the obtained results and the available literature data confirm the important role of both mushroom species and the tree on which the fungus has grown.

Toxicological risks and nutritional value of wild edible mushroom species -a half-century monitoring study.

The content of major- and trace elements in wild-growing mushrooms has been subject to numerous studies, but the data on long-term trends in this regard are scarce. The aim of research was to determine the content of 34 elements in four edible mushroom species Boletus edulis, Imleria badia, Leccinum scabrum and Macrolepiota procera, and associated soil collected from Polish forests between 1974 and 2019. As initially hypothesized, the element concentration in the studied soil revealed an increasing trend and was positively correlated with their levels found in fruit bodies. Bioconcentrafion Factor values exceeding 1 were documented for all mushroom species for K, P, Ag, Cd, Cu, Hg, and Zn. When compared to the Adequate Intakes, all the mushroom species were found to be a good dietary source of K, P, and Zn (range of 6260-8690, 6260-8690 and 97-135 mg kg-1 dry weight (dw), respectively), and B. edulis and I. badia a moderate source of Fe (mean 71.5 and 76.5 mg kg-1 dw, respectively), B. edulis of Mn and Mo (mean 20.0 and 0.42 mg kg-1 dw, respectively), while L. scabrum and M. procera a source of Cu. Consumption of the studied mushrooms would not lead to significant exposure to Al, As, Cr, or Ni. Considering that wild mushrooms will continue to be collected in Poland, one should bear in mind that they are a limited source of minerals in the human diet while their frequent, regular consumption, associated with exposure to selected toxic elements, should not be recommended.

Family and species as determinants modulating mineral composition of selected wild-growing mushroom species.

It has been known since the 1970s that differences exist in the profile of element content in wild-growing mushroom species, although knowledge of the role of mushroom species/families as determinants in the accumulation of diverse element remains limited. The aim of this study was to determine the content of 63 mineral elements, divided into six separate groups in the fruit bodies of 17 wild-growing mushroom species. The mushrooms, growing in widely ranging types of soil composition, were collected in Poland in 2018. Lepista nuda and Paralepista gilva contained not only the highest content of essential major (531 and 14,800 mg kg-1, respectively of Ca and P) and trace elements (425 and 66.3 mg kg-1, respectively of Fe and B) but also a high content of trace elements with a detrimental health effect (1.39 and 7.29 mg kg-1, respectively of Tl and Ba). A high content of several elements (Al, B, Ba, Bi, Ca, Er, Fe, Mg, Mo, P, Sc, Ti or V) in L. nuda, Lepista personata, P. gilva and/or Tricholoma equestre fruit bodies belonging to the Tricholomataceae family suggests that such species may be characterised by the most effective accumulation of selected major or trace elements. On the other hand, mushrooms belonging to the Agaricaceae family (Agaricus arvensis, Coprinus comatus and Macrolepiota procera) were characterised by significant differences in the content of all determined elements jointly, which suggests that a higher content of one or several elements is mushroom species-dependent. Graphical abstract.

Multiannual monitoring (1974-2019) of rare earth elements in wild growing edible mushroom species in Polish forests.

There is a growing demand for rare earth elements (REEs) due to their use in modern technologies, and this may result in their emission to the environment. This is the first long-term study to monitor the content of REEs in four edible mushroom species. Over 21,900 samples of fruit bodies (sporocarps) of Boletus edulis, Imleria badia, Leccinum scabrum and Macrolepiota procera and their underlying soils, collected between 1974 and 2019 from 42 forest sites in Poland were examined in an attempt to understand the time evolution of the presence of REEs in the environment. In general, I. badia and B. edulis displayed a greater total content of REEs on mg per kg basis than L. scabrum and M. procera. A gradual increase in REEs in the studied mushrooms as well as associated forest soil samples was observed over the monitored period. Both levels were also highly correlated. Regardless of the considered period, human consumption of these mushrooms would not contribute significantly to dietary exposure to REEs. Wild growing mushroom species studied over a long time period may be a good bioindicator of REE migration to the environment.

The effect of drying temperature on bioactive compounds and antioxidant activity of Leccinum scabrum (Bull.) Gray and Hericium erinaceus (Bull.) Pers.

In the study the effect of drying temperature on phenolic and organic acid content, total phenolic content, ergosterol content, antioxidant activity and content of 40 elements in fruiting bodies of Leccinum scabrum and Hericium erinaceus was estimated. The analysis was performed for fresh fruiting bodies and those dried at 20, 40 and 70 °C. Drying resulted in changes in the profile of phenolic and organic acids. Drying generally resulted in losses of the content of total phenolics, ergosterol and antioxidant activity in both species. However, a reduction and an increase of phenolic acids and organic acids were observed. The greatest reduction of the compounds was generally observed at 70 °C. The greatest losses concerned organic acids (some single components and total) (even more than 90% of some compounds). The inhibition of free radicals decreased in the following order: fresh samples > air-dried samples > samples dried at 40 °C > samples dried at 70 °C. The drying temperature affected only selected element contents in fruiting bodies.

Worldwide basket survey of multielemental composition of white button mushroom Agaricus bisporus.

Agaricus bisporus is the most commonly cultivated and consumed mushroom species. The aim of this study was to compare the profile of macro- and trace elements in A. bisporus fruit bodies produced commercially in 19 countries in 2018 and distributed worldwide (32 analyzed objects). Trace elements with unknown biological roles were also determined. The content of 36 elements (of 70 taken into account) revealed significant differences among the analyzed objects. Contents of Ca, K, Mg, Na and S varied in wide ranges of 425-2430, 12740-40940, 610-3240, 98-430 and 1030-2650 mg kg-1 dw, respectively. The fruit bodies were characterized by a generally similar content of trace elements with some clear exceptions. Rankings of the objects according to the decreased amount of macroelements, trace elements and all elements jointly, show that mushrooms are significantly diverse as regards the content of particular elements of the mentioned group. The analyzed fruit bodies displayed a relatively high content of Ca, Mo and Se, and a high K/Na ratio. Regardless of origin, A. bisporus did not constitute a source of significant levels of Al, Cd or rare earth elements. An increased level of As and Pb in mushrooms from several producers indicates a need for additional measures to reduce potential dietary exposures to these toxicants.

The Effect of Mushroom Extracts on Human Platelet and Blood Coagulation: In vitro Screening of Eight Edible Species.

Cardiovascular diseases remain the leading global cause of mortality indicating the need to identify all possible factors reducing primary and secondary risk. This study screened the in vitro antiplatelet and anticoagulant activities of hot water extracts of eight edible mushroom species (Agaricus bisporus, Auricularia auricularia-judae, Coprinus comatus, Ganoderma lucidum, Hericium erinaceus, Lentinula edodes, Pleurotus eryngii, and Pleurotus ostreatus) increasingly cultivated for human consumption, and compared them to those evoked by acetylsalicylic acid (ASA). The antioxidant capacity and concentration of polysaccharides, phenolic compounds, organic acids, ergosterol, macro elements, and trace elements were also characterized. The most promising antiplatelet effect was exhibited by A. auricularia-judae and P. eryngii extracts as demonstrated by the highest rate of inhibition of adenosine-5'-diphosphate (ADP)-induced and arachidonic acid (AA)-induced aggregation. The response to both extracts exceeded the one evoked by 140 µmol/L of ASA in the ADP test and was comparable to it in the case of the AA test. Such a dual effect was also observed for G. lucidum extract, even though it was proven to be cytotoxic in platelets and leukocytes. The extract of P. ostreatus revealed an additive effect on AA-induced platelet aggregation. None of the mushroom extracts altered the monitored coagulation parameters (prothrombin time, prothrombin ratio, and International Normalized Ratio). The effect of mushroom extracts on platelet function was positively related to their antioxidative properties and concentration of polysaccharides and ergosterol, and inversely related to zinc concentration. The study suggests that selected mushrooms may exert favorable antiplatelet effects, highlighting the need for further experimental and clinical research in this regard.

Fungal (1 → 3)-α-d-glucans as a new kind of biosorbent for heavy metals.

Although the fungal ability to bind heavy metals has been known for many years, it was not determined which component is responsible for this process. The aim of the study was to isolate (1 → 3)-α-d-glucans from various fungi, select the most efficient compound in the biosorption of heavy metals, and determine its characteristics. The best α-glucan for treatment of aqueous solutions from heavy metals (Ni2+, Cd2+, Zn2+, Pb2+) is the polymer isolated from Shiitake, especially its SH 37 variety. Using various techniques, it was confirmed that the studied polysaccharide consists mainly of glucose molecules (75.9%), i.e. glucose α-anomers linked by (1 → 3)-linkage (86%). The well-developed surface, low crystallinity, and the large number of -OH groups provide this polymer with good sorption properties. Probably, the main mechanism of metal uptake is metabolism-independent process that depends on the content and spatial structure of the glucans present in their cell wall.