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.

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.

Possible sources of rare earth elements near different classes of road in Poland and their phytoextraction to herbaceous plant species.

The growing use of rare earth elements (REE) in industry determines their increased transport to the environment. The higher concentration of this group of elements in soils near roads may also suggest that traffic plays a significant role in their distribution. The aim of this study was to examine the content of REEs in selected consumables (car parts, asphalt) and environmental samples (plants, soils) in order to estimate the extent to which these elements derive from traffic and also to analyze their phytoextraction from soil by selected herbaceous plants species. Research materials were car parts (5 brake pads, 10 new tires - summer and winter), 20 samples of asphalt and road dust settled on its surface; soil, and 7 plants species growing at a distance of 1 m from the edge of the 5 roads located in the Wielkopolska Voivodeship, Poland. The content of REEs in the collected samples was determined using inductively coupled plasma optical emission spectrometer. The content of REEs in asphalt and brake pads was similar and significantly higher than in tires. According to the mass of particular stripped materials, the main source of these elements was asphalt. The amount of REEs released from tires to the environment was found to be much lower than REEs released from asphalt but generally higher than from brake pads. The content of REEs in the soil was found to increase in accordance with traffic intensity, but chemical composition of soil was the main determinant of the uptake these elements, mainly via the root systems of plants. The obtained results suggest that densely vegetated roadsides and verges could be an effective strategy for decontamination of soils polluted with REEs, although the most effective remedy would involve significant changes in the production technologies of automotive parts and asphalt that would limit the emission of elements to environment.

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.

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.

Phytoextraction of arsenic forms in selected tree species growing in As-polluted mining sludge.

The aim of this study was to determine the phytoextraction of inorganic (As(III), As(V)) and organic arsenic (Asorg) forms in six tree species: Acer platanoides, Acer pseudoplatanus, Betula pendula, Quercus robur, Tilia cordata and Ulmus laevis. Plants were grown in a pot experiment using As-polluted mining sludge for 90 days. Arsenic (Astotal) was accumulated mainly in the roots of all six tree species, which were generally thinner, shorter and/or black after the experiment. The highest concentration of As(III) and As(V) was determined in the roots of A. pseudoplatanus and A. platanoides (174 and 420 mg kg-1, respectively). High concentrations of As(III) were also recorded in the shoots of B. pendula (11.9 mg kg-1) and As(V) in the aerial parts of U. laevis and A. pseudoplatanus (77.4 and 70.1 mg kg-1). With some exceptions, the dominant form in the tree organs was Asorg, present in mining sludge in low concentration. This form has a decisive influence on As phytoextraction by young tree seedlings even though its BCF value was the only one lower than 1. The obtained results highlight the important role of speciation studies in assessing the response of plants growing in heavily polluted mining sludge.

Salix viminalis L. - A highly effective plant in phytoextraction of elements.

The aim of the study was to compare specimens of Salix viminalis L. able to grow in polluted mining sludge (A1) with specimens of the same willow clone growing in two unpolluted areas (A2 and A3). Plants from the polluted area were characterized by the highest accumulation of the majority of elements in their organs with a clear limitation of their uptake to roots and effective translocation to aboveground organs. Willows from the unpolluted areas were characterized by significantly higher biomass than the treated plants, as shown in the content of cellulose/holocellulose. The different chemical characteristics of the substrates influenced tree physiology, including the organic acids and phenolic compounds profile and/or content. The total content of organic acids in lateral roots was higher for S. viminalis L. grown in unpolluted areas, while for leaves the opposite situation was observed. However, their creation was significantly correlated with the content of the majority of elements in the organs of S. viminalis L. Enhanced synthesis of phenolic compounds in roots (besides quercetin) and in leaves (besides myricetin and quercetin) was confirmed in the polluted area, and correlated with metal content in plant organs. Resilient plants characterized not only by their survivability but also by their effective phytoextraction of toxic metals, have great potential for widespread practical application on highly polluted mining sludge and for reducing the associated threat to human health. The obtained results suggest that further investigation of these plants is necessary to determine the mechanism(s) responsible for their high survivability.

Relationship between concentration of rare earth elements in soil and their distribution in plants growing near a frequented road.

Rare earth elements (REEs) are a group of elements whose concentration in numerous environmental matrices continues to increase; therefore, the use of biological methods for their removal from soil would seem to be a safe and reasonable approach. The aim of this study was to estimate the phytoextraction efficiency and distribution of light and heavy (LREEs and HREEs) rare earth elements by three herbaceous plant species: Artemisia vulgaris L., Taraxacum officinale F.H. Wigg. and Trifolium repens L., growing at a distance of 1, 10, and 25 m from the edge of a frequented road in Poland. The concentration of REEs in soil and plants was highly correlated (r > 0.9300), which indicates the high potential of the studied plant species to phytoextraction of these elements. The largest proportion of REEs was from the group of LREEs, whereas HREEs comprised only an inconsiderable portion of the REEs group. The dominant elements in the group of LREEs were Nd and Ce, while Er was dominant in the HREEs group. Differences in the amounts of these elements influenced the total concentration of LREEs, HREEs, and finally REEs and their quantities which decreased with distance from the road. According to the Friedman rank sum test, significant differences in REEs concentration, mainly between A. vulgaris L., and T. repens L. were observed for plants growing at all three distances from the road. The same relation between A. vulgaris L. and T. officinale was observed. The efficiency of LREEs and REEs phytoextraction in the whole biomass of plants growing at all distances from the road was A. vulgaris L. > T. officinale L. > T. repens L. For HREEs, the same relationship was recorded only for plants growing at the distance 1 m from the road. Bioconcentration factor (BCF) values for LREEs and HREEs were respectively higher and lower than 1 for all studied plant species regardless of the distance from the road. The studied herbaceous plant species were able to effectively phytoextract LREEs only (BCF > 1); therefore, these plants, which are commonly present near roads, could be a useful tool for removing this group of REEs from contaminated soil.