Three edible mushroom species (Imlera badia, Boletus subtomentosus, Xerocomellus chrysenteron) sampled in 60 different localities of Slovakia were evaluated to determine health risks (associated with mercury content) arising from their consumption. Total content of mercury in soil and mushroom samples was determined by an AMA-254 analyzer. Soil pollution by mercury was evaluated by contamination factor (C_f), pollution load index (PLI), and geoaccumulation index (I_geo). Bioaccumulation factor (BAF), translocation factor (Qc/s), provisional tolerably weekly intake (%PTWI), estimated daily intake (EDI), and target hazard quotient (THQ) were used to describe and compare uptake and transition abilities of mushrooms, and the health risk arising from mushroom consumption. Mercury content in soil significantly influences the content of mercury in mushroom fruiting body parts. Caps and stipes of Boletus subtomentosus were found to be the best mercury accumulator. According to the EDI, consumption of the evaluated mushroom species represents a serious threat for adults and children. The lowest values of THQ were found for Xerocomellus chysenteron.

In the present work, we focused on two aspects of mercury (Hg) bioconcentration in the above-ground parts of Neoboletus luridiformis. In the first part, we monitored the bioconcentration potential of individual anatomical parts of a particular fruiting body and evaluated the obtained data by the spline interpolation method. In the second part, we focused on assessing the mercury content in 378 samples of N. luridiformis and associated samples of substrates from 38 localities with different levels of Hg content in Slovakia. From the obtained data of Hg content in samples of substrate and fungi, we evaluated ecological indicators (geoaccumulation index - Igeo, contamination factor - Cf a potential ecological risk - PER), bioconcentration indicators (bioconcentration factor - BCF; cap/stipe quotient - Qc/s) and health indicators (percentage of provisional tolerable weekly intake - %PTWI a target hazard quotient - THQ). Based on the Hg distribution results, the highest Hg content was found in the tubes & pores (3.86 mg/kg DW), followed by the flesh of cap (1.82 mg/kg DW). The lowest Hg content was in the stipe (1.23 mg/kg DW). The results of the BCF values indicate that the studied species can be included in the category of mercury accumulators. The results of the ecological indices representing the state of soil pollution pointed out that two localities (Malachov and Nižná Slaná) stood apart from all monitored localities and showed a state of an extremely disturbed environment. This fact was also reflected in the values of Hg content in the fruiting bodies of the studied mushroom species. In the case of the consumption of mushrooms from these localities, it can be stated that long-term and regular consumption could have a negative non-carcinogenic effect on the health of consumers. It was confirmed by the %PTWI (Malachov: 57.8%; Nižná Slaná: 53.2%) and THQ (Malachov: 1.11 Nižná Slaná: 1.02). The locality Čačín-Jelšovec is interesting from the bioconcentration characteristics point of view, where the level of environmental pollution was the lowest (Hg content in the soil was below the background value) compared to other localities, however, the THQ value was the highest (1.29).

Old-growth forest fungi – new localities and habitat and host preferences in Slovakia (I). - abstract

The dichloromethane extraction was applied to extracted volatile compounds of the six developmental stages of caps and stipes of an Amanita rubescens mushroom and the relative contents were measured with the gas chromatography-mass spectrometry. The number of identified compounds ranged between 53 and 52, respectively, with a high ratio of alkane volatiles. The significant differences between the aroma compounds were determined in caps to identify their stages of development. The fully mature stage caps were characterized by 4,6-dimethyl-dodecane (7.69 ± 1.15%), 2-hexyl-1-decanol (11.8 ± 1.61%), 1,3-di-tert-butylbenzene (11.4 ± 1.25%), heptadecyl pentadecafluorooctanoate (2.16 ± 0.31%), and 2-hexyl-1-dodecanol (13.5 ± 1.33%). Niacinamide (3.90 ± 0.07%) and glycerol (3.62 ± 1.27%) was present in the caps in the early-stage of the rotting mushroom, which represented the 10th–12th day of fructification. The caps and stipes from the 12th–15th day of fructification were characterized by 2,3-butanediol (11.7 ± 0.13% and 8.00 ± 0.10%, respectively). Moreover, the caps from this developmental stage were characterized by 2-methyl- and 3-methyl butanoic acids (0.18 ± 0.03% and 0.33 ± 0.02%, respectively) which are typical for the rotting stage. In this study, we confirmed the effect of A. rubescens developmental stages on the aroma profile.

In September 2011, an international team of cryptogam experts visited seven national nature reserves in five mountain areas of Slovakia: Havešová and Stužica in the Poloniny Mts., Vihorlat in the Vihorlatské vrchy Mts., Oblík in the Slanské vrchy Mts., Dobročský prales and Klenovský Vepor in the Veporské vrchy Mts. and Badínsky prales in the Kremnické vrchy Mts. The reserves were selected to represent examples of the best protected old-growth beech forests in the country. The aim was to study the diversity of wood-inhabiting fungi on fallen beech logs and epiphytic lichens on standing beech trees. In total, 215 fungal species and 128 lichens were recorded on beech wood and bark, and 27 fungi and 26 lichens on additional substrates. The site of the highest conservation value is Stužica with 126 fungi and 79 lichens recorded on beech, of which 12 fungi and 19 lichens are indicators of high nature conservation value. Combined with historical records, a total of 19 non-lichenised fungal indicators are now reported from the site, making it the highest ranked natural beech forest in Europe. The second most important reserve for fungal diversity is Havešová with 121 species, including 14 indicator species recorded on beech wood. For lichens, the second most important reserve is Klenovský Vepor with 69 species including 18 lichen indicators recorded on beech. Nine fungus species are here reported as new to Slovakia: Asterostroma medium, Entoloma hispidulum, E. pseudoparasiticum, Gloeohypochnicium analogum, Hohenbuehelia valesiaca, Hymenochaete ulmicola, Hypocrea parmastoi, Melanomma spiniferum and Scutellinia colensoi. Lichen species Alyxoria ochrocheila is reported as new to Slovakia and Lecanographa amylacea, which was considered extinct in the Slovak Red list, was also recorded. This is the first list of wood-inhabiting fungi and epiphytic lichens of old-growth beech forests in Slovakia, and hence an important contribution to the exploration of biodiversity in Slovakia.