Research Progress on Elements of Wild Edible Mushrooms

Adverse effect of TWPs on soil fungi and the contribution of benzothiazole rubber additives

Tire wear particles (TWPs) pollution is widely present in soil, especially in areas severely affected by traffic. Herein, regular variation of fungal biomass with TWPs was found in soils with different distances from the highway. In addition, the concentrations of benzothiazole compounds (BTHs), an important class of rubber vulcanization accelerators, were found to be positively correlated to the TWPs abundance. Sixty days' soil microcosm experiments were conducted to further confirm the adverse effect of TWPs and BTHs on soil fungi. TWPs spiking at 1000 mg/kg, a detectable level in the roadside, resulted in significant reduction of biomass and significant changes of soil fungal community structure, with Eurotium and Polyporales being the sensitive species. BTH+ 2-hydroxybenzothiazole (OHBT) (the dominant BTHs in soil) spiking at 200 ng/kg, the dose equivalent to 1000 mg/kg TWPs pollution, also caused a similar magnitude of soil fungal biomass reduction. Adonis demonstrated no significant difference of fungal community structure between TWPs and BTH+OHBT spiked soil, suggesting the adverse effect of TWPs on soil fungi may be explained by the act of BTHs. Pure culture using the representative soil fungi Eurotium and Polyporales also confirmed that BTHs were the main contributors to the adverse effect of TWPs on soil fungi.

Metals Transfer in Mushroom Tricholoma matsutake from Regional High Geochemical Background Areas: Environmental Influences and Human Health Risk

Wild-grown edible mushrooms are important in world diets and are also efficient metal accumulators. Yunnan, Southwest China, is the main producing region, with typically high levels of geochemical metals. The environmental factors, bioaccumulation, distribution and human health risks of metals were examined in paired soil and Tricholoma matsutake (n = 54). T. matsutake grows on acidified soils (pH = 3.95-6.56), and metals show a strong heterogeneity, with Fe, Mn, Zn and Cu in the ranges of 16-201, 0.046-8.58 g kg-1, and 22.6-215, 3.7-155 mg kg-1. High soil Fe content led to great accumulation in T. matsutake (0.24-18.8 g kg-1). However, though the soil Mn content was higher than that of Zn and Cu, their concentrations in T. matsutake were comparable (21.1-487 vs. 38.7-329 and 24.9-217 mg kg-1). This suggested that T. matsutake prefers to accumulate Zn and Cu compared to Mn, and this is supported by the bioaccumulation factors (BAFs = 0.32-17.1 vs. 0.006-1.69). Fe was mainly stored in stipes, while Mn, Zn and Cu were stored in caps, and the translocation factors (TFs) were 0.58 vs. 1.28-1.94. Therefore, stipe Fe showed the highest health risk index (HRI) at 1.28-26.9, followed by cap Cu (1.01-2.33), while 98-100% of the Mn and Zn were risk-free. The higher concentration and greater risk of Fe was attributed to the significant effect of soil Fe content (R = 0.34) and soil pH (R = -0.57). This study suggested that Fe, as an essential mineral, may exert toxic effects via the consumption of T. matsutake from high geochemical background areas.

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.

Mercury abatement in the environment: Insights from industrial emissions and fates in the environment

Mercury's neurotoxic effects have prompted the development of advanced control and remediation methods to meet stringent measures for industries with high-mercury feedstocks. Industries with significant Hg emissions, including artisanal and small-scale gold mining (ASGM)-789.2 Mg year-1, coal combustion-564.1 Mg year-1, waste combustion-316.1 Mg year-1, cement production-224.5 Mg year-1, and non-ferrous metals smelting-204.1 Mg year-1, use oxidants and adsorbents capture Hg from waste streams. Oxidizing agents such as O3, Cl2, HCl, CaBr2, CaCl2, and NH4Cl oxidize Hg0 to Hg2+ for easier adsorption. To functionalize adsorbents, carbonaceous ones use S, SO2, and Na2S, metal-based adsorbents use dimercaprol, and polymer-based adsorbents are grafted with acrylonitrile and hydroxylamine hydrochloride. Adsorption capacities span 0.2-85.6 mg g-1 for carbonaceous, 0.5-14.8 mg g-1 for metal-based, and 168.1-1216 mg g-1 for polymer-based adsorbents. Assessing Hg contamination in soils and sediments uses bioindicators and stable isotopes. Remediation approaches include heat treatment, chemical stabilization and immobilization, and phytoremediation techniques when contamination exceeds thresholds. Achieving a substantially Hg-free ecosystem remains a formidable challenge, chiefly due to the ASGM industry, policy gaps, and Hg persistence. Nevertheless, improvements in adsorbent technologies hold potential.

Exploiting Agri-Food Waste as Feed for Tenebrio molitor Larvae Rearing: A Review

The agri-food industry generates substantial amounts of waste, including by-products and residues. The increasing demand for sustainable and eco-friendly practices in the agri-food sector has sparked an interest in finding alternative uses for such waste materials. One promising approach is the utilization of waste from the agri-food industry as feed for the rearing of mealworms (Tenebrio molitor). Since agri-food waste is rich in proteins, carbohydrates, lipids, and vitamins, as well as other bioactive compounds, all of which are essential for insect growth and development, incorporating such waste into the diet of mealworms promotes sustainable insect production, reducing the economic and environmental problems associated with waste disposal. This practice can also be beneficial for the rearing of mealworms since their nutritional value can also be enhanced. To this end, various waste materials, such as fruit and vegetable peels, spent grains, and food processing residues, have been investigated as potential feed sources, leading to increased mass production, lower cost, and enhanced nutritional value. This review aims to highlight the potential of agri-food waste as a feed source for mealworms, as well as their potential to enhance their nutritional value. Furthermore, the potential applications of mealworms reared on agri-food waste are highlighted, including their potential as a sustainable protein source for human consumption and as feed ingredients in the livestock and aquaculture sectors.

Phylogenetic analysis, morphological studies, element profiling, and muscarine detection reveal a new toxic Inosperma (Inocybaceae, Agaricales) species from tropical China

Tropical Asian collections of Inosperma are usually poisonous mushrooms that have caused many poisoning incidents. However, the species diversity and the toxic mechanisms of these Inosperma species are still unclear. In this study, we describe the discovery of Inosperma wuzhishanense sp. nov. from Wuzhishan City, Hainan Province, tropical China. The new species was identified based on morphological and multi-locus (ITS, nrLSU, and RPB2) phylogenetic analyses. The new species is characterized by its reddish-brown pileus, fibrillose stipes with finely protruding fibrils, rather crowded lamellae, smooth and ellipsoid basidiospores, and mostly clavate, thin-walled cheilocystidia. The new species is phylogenetically nested in the Old World tropical clade 2 and is sister to the tropical Indian taxa I. akirnum. Detailed descriptions, color photos of the new species, and comparisons with its closely related species are provided. Additionally, the muscarine content of the new species was analyzed by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). The muscarine contents ranged from 4,359.79 ± 83.87 mg/kg to 7,114.03 ± 76.55 mg/kg, 2,748.37 ± 106.85 mg/kg to 4,491.35 ± 467.21 mg/kg, and 2,301.36 ± 83.52 mg/kg to 2,775.90 ± 205.624 mg/kg in the stipe, pileus, and lamellae, respectively. The elemental composition and concentration were determined using inductively coupled plasma-mass spectrometry (ICP-MS). A total of 24 elements were detected. Among the heavy metals detected, arsenic showed the highest level of toxicity with a concentration of 36.76 ± 0.43 mg/kg.

Simultaneous Quantitative Determination of Low-Concentration Preservatives and Heavy Metals in Tricholoma Matsutakes Based on SERS and FLU Spectral Data Fusion

As an ingredient of great economic value, Tricholoma matsutake has received widespread attention. However, heavy metal residues and preservatives in it will affect the quality of Tricholoma matsutake and endanger the health of consumers. Here, we present a method for the simultaneous detection of low concentrations of potassium sorbate and lead in Tricholoma matsutakes based on surface-enhanced Raman spectroscopy (SERS) and fluorescence (FLU) spectroscopy to test the safety of consumption. Data fusion strategies combined with multiple machine learning methods, including partial least-squares regression (PLSR), deep forest (DF) and convolutional neural networks (CNN) are used for model training. The results show that combined with reasonable band selection, the CNN prediction model based on decision-level fusion achieves the best performance, the correlation coefficients (R2) were increased to 0.9963 and 0.9934, and the root mean square errors (RMSE) were reduced to 0.0712 g·kg-1 and 0.0795 mg·kg-1, respectively. The method proposed in this paper accurately predicts preservatives and heavy metals remaining in Tricholoma matsutake and provides a reference for other food safety testing.

Edible and Medicinal Macrofungi

Macrofungi are well known as mushrooms, which belong mostly to Basidiomycota with a few from Ascomycota, and up to now, around 40,000 species have been described. In people's lives, macrofungi are closely related to our economic activities, especially for food and medicine. "One meat, one vegetable and one mushroom" has become a healthy and fashionable dietary structure, and the global edible mushroom production and cultivating area are steadily rising. On the other hand, a large number of mushroom species and new active components have been found, and have become one of the driving forces of innovation of drugs and health products, especially with the development of biochemistry, enzyme engineering, and genetic engineering. Thus, macrofungi in food, medicine, and other aspects have shown a broad prospect. In this Special Issue, research on new species and related molecular phylogenies, mechanisms of hyphae polar growing and basidiocarp formation, biochemistry of edible and medical mushrooms, and some important scientific questions related to the edible mushroom industry are presented, which also reflect the hot areas of common concern on edible and medicinal fungi.

Exploring Edible Mushrooms for Diabetes: Unveiling Their Role in Prevention and Treatment

Diabetes mellitus is a complex illness in which the body does not create enough insulin to control blood glucose levels. Worldwide, this disease is life-threatening and requires low-cost, side-effect-free medicine. Due to adverse effects, many synthetic hypoglycemic medications for diabetes fail. Mushrooms are known to contain natural bioactive components that may be anti-diabetic; thus, scientists are now targeting them. Mushroom extracts, which improve immune function and fight cancer, are becoming more popular. Mushroom-derived functional foods and dietary supplements can delay the onset of potentially fatal diseases and help treat pre-existing conditions, which leads to the successful prevention and treatment of type 2 diabetes, which is restricted to the breakdown of complex polysaccharides by pancreatic-amylase and the suppression of intestinal-glucosidase. Many mushroom species are particularly helpful in lowering blood glucose levels and alleviating diabetes symptoms. Hypoglycaemic effects have been observed in investigations on Agaricussu brufescens, Agaricus bisporus, Cordyceps sinensis, Inonotus obliqus, Coprinus comatus, Ganoderma lucidum, Phellinus linteus, Pleurotus spp., Poria cocos, and Sparassis crispa. For diabetics, edible mushrooms are high in protein, vitamins, and minerals and low in fat and cholesterol. The study found that bioactive metabolites isolated from mushrooms, such as polysaccharides, proteins, dietary fibers, and many pharmacologically active compounds, as well as solvent extracts of mushrooms with unknown metabolites, have anti-diabetic potential in vivo and in vitro, though few are in clinical trials.

The Addition of Reishi and Lion’s Mane Mushroom Powder to Pasta Influences the Content of Bioactive Compounds and the Antioxidant, Potential Anti-Inflammatory, and Anticancer Properties of Pasta

The influence of a 2.5% and 5% addition of dried Reishi and Lion’s Mane mushrooms on the content of bioactive compounds and some pro-health properties of pasta was studied. In samples subjected to gastrointestinal digestion, the content of phenolic compounds and the antioxidant, potential anti-inflammatory, and antiproliferative properties were significantly higher. The qualitative–quantitative analysis of phenolic compounds performed using the LC-MS/MS technique indicated that the Reishi-enriched pasta was characterized by a higher content of syringic (R2.5 sample), while pasta supplemented with Lion’ Mane had a higher content of vanillin in relation to the control pasta. In the case of ethanolic extracts, samples supplemented with the Reishi mushrooms (R5 sample) were characterized by higher ABTS antiradical properties and a reducing power while the sample supplemented with Lion’s Mane (L5 sample) had a higher ability to inhibit lipoxygenase in relation to the control sample. In conclusion, the results suggest that Reishi and Lion’s Mane mushroom powder can be used for the fortification of semolina pasta, conferring slightly healthier characteristics of the product.

Risk Assessment of the Wild Edible Leccinum Mushrooms Consumption According to the Total Mercury Content

Wild-growing edible mushrooms contain many biologically valuable substances. However, they are considered a risk commodity due to their extremely high capacity for bioaccumulation of potential risk elements and pollutants from the environment. Four bolete mushrooms from the genus Leccinum were collected from 16 forested areas of Slovakia from June to October 2019. The total mercury content in soil and fruiting body parts was determined by an AMA-254 Advanced Mercury Analyzer. Soil pollution by total mercury was evaluated by contamination factor (Cfi). Bioaccumulation factor (BCF), translocation factor (Qc/s), percentage of provisional tolerable weekly intake (%PTWI), and target hazard quotient (THQ) were used to describe and compare uptake and transition abilities of mushrooms, and the health risk arising from consumption of the mushrooms. Total mercury content varied between 0.05 to 0.61 mg kg-1 DW in the soil/substrate samples, and between 0.16 and 5.82 (caps), and 0.20 and 3.50 mg kg-1 DW (stems) in fruiting body samples. None of the analyzed locations represented a health risk based on %PTWI values, however, three locations may pose a significant health risk from the perspective of THQ values.

Lead detoxification of edible fungi Auricularia auricula and Pleurotus ostreatus: the purification of the chelation substances and their effects on rats

Lead is a global pollutant that causes widespread concern. When a lead enters the body, it is distributed throughout the body and accumulates in the brain, bone, and soft tissues such as the kidney, liver, and spleen. Chelators used for lead poisoning therapy all have side effects to some extent and other drawbacks including high cost. Exploration and utilization of natural antidotes become necessary. To date, few substances originating from edible fungi that are capable of adsorbing lead have been reported. In this study, we found that two commonly eaten mushrooms Auricularia auricula and Pleurotus ostreatus exhibited lead adsorption capacity. A. auricula active substance (AAAS) and P. ostreatus active substance (POAS) were purified by hot-water extraction, ethanol precipitation from its fruiting bodies followed by ion exchange chromatography, ultrafiltration, and gel filtration chromatography, respectively. AAAS was 3.6 kDa, while POAS was 4.9 kDa. They were both constituted of polysaccharides and peptides. The peptide sequences obtained by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) proved that they were rich in amino acids with side chain groups such as hydroxyl, carboxyl, carbonyl, sulfhydryl, and amidogen. Two rat models were established, but only a chronic lead-induced poisoning model was employed to determine the detoxification of AAAS/POAS and their fruiting body powder. For rats receiving continuous lead treatment, either AAAS or POAS could reduce the lead levels in the blood. They also promoted the elimination of the burden of lead in the spleen and kidney. The fruiting bodies were also proved to have lead detoxification effects. This is the first study to identify new functions of A. auricula and P. ostreatus in reducing lead toxicity and to provide dietary strategies for the treatment of lead toxicity.