Mushroom Quality Related with Various Substrates' Bioaccumulation and Translocation of Heavy Metals

Heavy Metals and Associated Risks of Wild Edible Mushrooms Consumption: Transfer Factor, Carcinogenic Risk, and Health Risk Index

This research aims to investigate the heavy metals (i.e., Cd, Cr, Cu, Ni, and Pb) in the fruiting bodies of six indigenous wild edible mushrooms including Agaricus bisporus, Agaricus campestris, Armillaria mellea, Boletus edulis, Macrolepiota excoriate, and Macrolepiota procera, correlated with various factors, such as the growth substrate, the sampling site, the species and the morphological part (i.e., cap and stipe), and their possible toxicological implications. Heavy metal concentrations in mushroom (228 samples) and soil (114 samples) were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In the first part of the study, the soil contamination (index of geo-accumulation, contamination factor, and pollution loading index) and associated risks (chronic daily dose for three exposure pathways-ingestion, dermal, and inhalation; hazard quotient of non-cancer risks and the carcinogenic risks) were calculated, while the phytoremediation capacity of the mushrooms was determined. At the end of these investigations, it was concluded that M. procera accumulates more Cd and Cr (32.528% and 57.906%, respectively), M. excoriata accumulates Cu (24.802%), B. edulis accumulates Ni (22.694%), and A. mellea accumulates Pb (18.574%), in relation to the underlying soils. There were statistically significant differences between the stipe and cap (i.e., in the cap subsamples of M. procera, the accumulation factor for Cd was five times higher than in the stipe subsamples). The daily intake of toxic metals related to the consumption of these mushrooms with negative consequences on human health, especially for children (1.5 times higher than for adults), was determined as well.

Biological properties of vitamin B12

Vitamin B12, cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l-methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B12, in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B12 deficiency and it is recommended that they consume fortified food. Vitamin B12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.

Role of white rot fungi in sustainable remediation of heavy metals from the contaminated environment

Heavy metal contamination has severe impacts on the natural environment. The currently existing physico-chemical methods have certain limitations, restricting their wide-scale application. The use of biological agents like bacteria, algae, and fungi can help eliminate heavy metals without adversely affecting flora and fauna. Due to their inherent ability to withstand adverse environmental conditions, nowadays, mycoremediation approaches are receiving considerable attention for heavy metal removal from contaminated sites. In this review, we emphasised the role of white rot fungi in remediation of heavy metal along with different factors influencing biosorption, effects on exposed fungi, and the mechanisms involved. Bibliometric analysis tools have been applied to literature search and trend analysis of the research on white rot fungi-mediated heavy metal removal. Annual growth rates and average citations per document are 5.08% and 35.48, respectively. Phanerochaete chrysosporium, Pleurotus ostreatus, and Trametes versicolor have been widely explored for the remediation of heavy metals. In addition to providing some prospects, the review also highlighted a few limitations, including inconsistent removal and effects of environmental factors influencing the functioning of white rot fungi. Overall, white rot fungi have been found to have immense potential to be widely utilised for sustainable remediation of heavy metal-contaminated environments.

Fungal species and element type modulate the effects of environmental factors on the concentration of potentially toxic elements in mushrooms

Numerous edible mushrooms accumulate Potentially Toxic Elements (PTE), such as cadmium, mercury, and lead, within their sporocarps. This accumulation poses a potential risk of poisoning for humans and is influenced by factors such as the mushroom species, type of element, and the level of industrialization in the region. In our study, we investigated how soil and tree stand characteristics, including C/N ratio, pH, tree diversity, canopy cover, and the proportion of deciduous trees, influence PTE concentration in mushrooms. We collected edible mushrooms from 20 plots situated in the Białowieża Primeval Forest, one of Europe's best-preserved lowland forests. Plots varied in terms of tree species composition, with other factors minimized. We used ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) technique to analyze the concentration of eight PTE (Ag, As, Cd, Ni, Pb, Sb, Sr, Tl) in eight edible mushroom species (M.procera, L.perlatum, R. butyracea, R.cyanoxantha, R.heterophylla, L.vellereus, A.mellea, and Xerocomellus chrysenteron). Our research revealed that the presence of the effect of specific factors on concentration of PTE and its direction depends on mushroom species and type of PTE. The proportion of deciduous tree species and pH of the topsoil layer emerged as the most influential factors affecting PTE concentration in mushroom samples. Tree species richness in the canopy layer did not affect PTE concentration in mushrooms, except for the concentration of Pb in X. chrysenteron. We observed a consistent profile of PTE concentration in mushrooms with similar ecological roles (ectomycorrhizal, saprotrophic, parasite mushrooms) and from comparable phylogenetic affinities.

Blusher mushroom (Amanita rubescens Pers.): A Study of Mercury Content in Substrate and Mushroom Samples from Slovakia with Respect to Locality and Developmental Stages

The edible mushroom Amanita rubescens Pers., regularly collected and consumed in Slovakia, was assessed for health risk due to the mercury content in its fruiting body parts. For this purpose, 364 both from the soil/substrate and mushroom samples from 40 localities in Slovakia were evaluated. At the same time, 21 samples of 7 developmental stages of the fruiting body of A. rubescens were taken in the Žakýlske pleso locality. The total mercury content in the soil and mushroom samples was determined using an AMA-254 analyzer. The contamination factor (Cf) and index of geoaccumulation (Igeo) were used to detect the level of soil pollution by mercury. The ability of A. rubescens to accumulate mercury from the soil environment was evaluated using the bioconcentration factor (BCF), and the distribution of mercury in the mushroom body was evaluated using the translocation quotient (Qc/s). To determine the health risks resulting from mushroom consumption, the percentages of provisional tolerable weekly intake (%PTWI) and target hazard quotient (THQ) were used. The obtained results have confirmed serious content of mercury soil pollution, especially in former mining areas, where the situation is alarming from a health risk point of view. Consumption of A. rubescens was found to be risky, not only in former mining areas, but higher values of mercury were also detected in other parts of Slovakia. Evaluation of the developmental stages of the fruiting body of A. rubescens showed that the highest bioconcentration factor was determined at developmental stage no. VI for caps with a value of 2.47 mg kg-1 and developmental stage VII for stipes with a value of 1.65 mg kg-1 DW.

Uptake of toxic and nutrient elements by foraged edible and medicinal mushrooms (sporocarps) throughout Connecticut River Valley, New England, USA

Foraging for edible and medicinal mushrooms is a cultural and social practice both globally and in the United States. Determining the toxic and nutrient element concentrations of edible and medicinal mushrooms is needed to ensure the safe consumption of this food source. Our research examined wild, foraged mushrooms in New England, USA to assess nutrient (Ca, K, Mg, P) and toxic (As, Hg, Pb, Cd) element relationships between mushrooms, substrates, and soils. We examined a gradient in nutrient and toxic elements from more rural Mountain and Hill Zones in Massachusetts, Vermont, and New Hampshire to more developed and urban Valley and Coastal Zones in Connecticut. Substrates and mineral soils were moderate to weak predictors of mushroom tissue concentrations. We found significant differences in nutrient and toxic element concentration among the five common genera: Ganoderma, Megacollybia, Pluteus, Pleurotus, and Russula. In particular, Pluteus had consistently higher toxic element concentrations while Pleurotus and Russula had the highest Bioaccumulation Factors (BAFs). We found that the urban areas of the Valley and Coastal zones of Connecticut had Cd Target Hazard Quotient (THQ) values and ΣTHQ values > 1.0, indicating potential non-carcinogenic health hazard. However, the trend was largely driven by the > 2.0 Cd THQ for Pluteus. Our results suggest that foraging in more urban areas can still yield mushrooms with safe concentrations of toxic elements and abundant nutrients. Further research of this kind needs to be conducted within this region and globally to ensure humans are consuming safe, foraged mushrooms.

Bioremoval of heavy metals from aqueous solution using dead biomass of indigenous fungi derived from fertilizer industry effluents: isotherm models evaluation and batch optimization

The present work investigated the utilization of dead biomass of the highly multi-heavy metals tolerant indigenous fungal strain NRCA8 isolated from the mycobiome of fertilizer industry effluents that containing multiple heavy metal ions at high levels to remove Pb2+, Ni2+, Zn2+, and Mn2+ as multiple solutes from multi-metals aqueous solutions for the first time. Based on morphotype, lipotype and genotype characteristics, NRCA8 was identified as Cladosporium sp. NRCA8. The optimal conditions for the bioremoval procedure in the batch system were pH 5.5 for maximum removal (91.30%, 43.25%, and 41.50%) of Pb2+, Zn2+ and Mn2+ but pH 6.0 supported the maximum bioremoval and uptake of Ni2+ (51.60% and 2.42 mg/g) by NRCA8 dead biomass from the multi-metals aqueous solution, respectively. The 30 min run time supported the highest removal efficiency and uptake capacity of all heavy metals under study. Moreover, the equilibrium between the sorbent NRCA8 fungal biomass and sorbates Ni2+, Pb2+ and Zn2+ was attained after increasing the dead biomass dose to 5.0 g/L. Dead NRCA8 biomass was described by scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectrometer before and after biosorption of Pb2+, Ni2+, Zn2+ and Mn2+ under multiple metals system. The Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich isotherms were applied to characterize the adsorption equilibrium between Pb2+, Ni2+, Mn2+ and Zn2+ and the adsorbent NRCA8. By comparing the obtained coefficient of regression (R2) by Freundlich (0.997, 0.723, 0.999, and 0.917), Langmiur (0.974, 0.999, 0.974, and 0.911) and Dubinin-Radushkevich (0.9995, 0.756, 0.9996 and 0.900) isotherms values for Pb2+, Zn2+, Ni2+ and Mn2+ adsorption, respectively, it was found that the isotherms are proper in their own merits in characterization the possible of NRCA8 for removal of Pb2+, Zn2+, Ni2+ and Mn2+. DKR isotherm is the best for Pb2+ and Ni2+ (0.9995 and 0.9996) while Langmiur isotherm giving a good fit to the Zn2+ sorption (0.9990) as well as Freundlich isotherm giving a good fit to the Mn2+ sorption (0.9170). The efficiencies of Cladosporium sp. NRCA8 dead biomass for bioremoval of heavy metals from real wastewater under the optimized conditions were Pb2+, Ag+, Mn2+, Zn2+ and Al3+ ˃ Ni2+ ˃ Cr6+ ˃ Co2+ ˃ Fe3+ ˃ Cu2+ ˃ Cd2+. Dead NRCA8 biomass showed efficient ability to adsorb and reduce harmful components in the industrial effluents to a level acceptable for discharge into the environment.

Current trends in palm oil waste management: A comparative review of Cameroon and Malaysia

This paper carried out a comparative review on the current trends in the conversion of palm oil waste into value-adding products by the Cameroonian and Malaysian palm sectors/researchers. Trends like composting, composite, pulping, mushroom cultivation, pyrolysis, aerobic and anaerobic digestion of palm biomass were studied as means to reduce the bulk, and to curb emissions of Greenhouse gas while producing value. Base on this research, limited works has been done on the conversion of palm biomass into value in Cameroon, whereas Malaysian palm researchers have employed all of these techniques and producing values from them. It was discovered that the various conversion process have different degree of feasibility and sustainability, and the end-products have different applications. Conversion process like pyrolysis is relatively faster, it could take just a few minute and the end-product which is biofuel have a wide range of applications; in contrast to composting which could take up to 180 days to mature and the end-product is limited to fertilizer. This research aims to sensitize the palm sector in Cameroon to the various processes that can be applied to sustainably manage palm waste. A priority table was also developed based on the feasibility and sustainability of the various conversion processes to serve as a guide towards sustainable waste management in the agro-industrial palm sector in Cameroon and a step towards industrialization.

Platinum and Palladium Accumulation in Edible Mushroom Boletus aereus Bull. Growing in Unpolluted Soils of Sicily Region (Italy)

Human exposure to certain metals occurs indirectly through diet. This study was conducted to determine the content of Pt and Pd in fruiting bodies of Boletus aereus Bull. collected from several wooded areas of Sicily with different substrates (sedimentary and volcanic) with limited anthropogenic influence. Determinations were performed by coupled plasma-mass spectrometry (ICP-MS) to quantify Pt and Pd. The concentrations of investigated Pt and Pd in mushroom samples ranged from 0.31 to 3.09 ng g-1 for palladium and 0.21 to 4.22 ng g-1 for platinum. The results of the present study suggest that commonly consumed Boletus aereus mushrooms do not accumulate significant levels of Pt and Pd as demonstrated by bioconcentration factor (BCF) values, and their content is lower than in other food products. Additionally, based on the calculated daily intake rates of Pt and Pd, it can be concluded that occasional consumption of fruiting bodies of B. aereus collected in Sicily is safe. The proposed methodological approach appears to be fully adequate for the reliable quantification of Pt and Pd. The data obtained in this investigation confirm that mushrooms are probative of a significant portion of the total exposure to PGEs due to the diet.

Multimetal bioremediation from aqueous solution using dead biomass of Mucor sp. NRCC6 derived from detergent manufacturing effluent

Among ten metal-tolerant fungal isolates obtained from the microbiomes of detergent industry effluent, Mucor sp. NRCC6 showed the highest tolerance and an adaptive behavior toward the heavy metals Ni2+, Pb2+, Mn2+, and Zn2+. It gave the highest growth rates 0.790 ± 0.59, 0.832 ± 0.32, 0.774 ± 0.40, and 0.741 ± 1.06 mm/h along with the lowest growth inhibition 9.19, 4.37, 11.04, and 14.83% in the presence of Pb2+, Zn2+, Ni2+, and Mn2+, respectively, at a concentration of 5.0 g/L. Then, Mucor sp. NRCC6 was selected as a biotrap for the removal of these heavy metals. The optimized operating conditions were detected to be pH 6.0 for Pb2+, Zn2+, and Mn2+ and pH 5.5 for Ni2+ at 30 °C; agitation speed 150 rpm; contact time 30 min for Mn2+ and Ni2+, 30-60 min for Pb2+, and 90-180 min for Zn2+; NRCC6 biomass dosage 5.0 g/L for Ni2+ and Pb2+ and 10.0 g/L for Mn2+ and Zn2+; and initial concentration 12 mg/L of each ion in the multimetal aqueous solutions. Under these optimized conditions, the adsorption capacity for Pb2+, Ni2+, Mn2+, and Zn2+ reached 98.75, 59.25, 58.33, and 50.83%. The Langmuir isotherm was the best for describing the adsorption of Zn2+ (0.970) and Mn2+ (0.977). The Freundlich isotherm significantly giving a good fit to the adsorption of Pb2+ (0.998) while the adsorption of Ni2+ onto NRCC6 biomass can follow DKR (0.998). Furthermore, the current study revealed that Mucor sp. NRCC6 fungus is a new efficient and eco-friendly method that revealed a maximum removal of 100% for Pb2+ and Zn2+ as well as 97.39, 88.70, 78.95, 74.0, 70.22, 68.57, and 60.0% for Ni2+, Mn2+, Cd2+, Cu2+, Fe3+, As2+, and Cr6+ from the industrial wastewater, respectively.

Antifungal Activity of Industrial Bacillus Strains against Mycogone perniciosa, the Causative Agent of Wet Bubble Disease in White Button Mushrooms

White button mushrooms yield instability in artificial cultivation, often caused by crop diseases. The main disease is wet bubble disease. The appearance of its causative agent, M. perniciosa, may lead to total yield loss. The microbiocontrol of M. perniciosa is focused on casing soil antagonist use. Since no industrial producer strains of polyfunctional biologics have been used in previous studies, our research goal was to characterize the effect of B. subtilis B-10 and M-22 on a mycopathogen and reveal its control possibilities. The reason for B. subtilis B-10 and M-22 use in mycopathogen control has been revealed by interactions between producer strains and the studying of M. perniciosa. The suppression of M. perniciosa development by producer strains was established, indicating a prolonged B-10 and M-22 effect on the mycopathogen. High biological efficacy in both strains at the early stages of mycopathogen development upon introducing them into the wells and spraying was shown: B-10-50.9-99.6% and M-22-57.5-99.2%, respectively (p ≤ 0.05). Significant differences between producer strains were not revealed, although during the first day of exposure to developed M. perniciosa colonies, M-22 showed greater activity. The high efficiency of preventive treatment when producer strains completely suppressed mycoparasite development permits us to recommend them both for introducing when preparing casing for M. perniciosa control.

Zinc bioaccessibility in finger millet porridge blended with zinc-dense mushroom

Introduction

Zinc deficiency is a common health problem among people who rely heavily on cereal-based foods. Consequently, most people from low-income families, particularly young children in Sub-Saharan Africa, who rely mainly on cereal-based meals, have suffered from Zinc deficiency-related health issues. It is therefore recommended that children who show signs of zinc deficiency like poor growth and cognitive impairment be fed zinc-rich meals; however, in severe cases, they should be given zinc supplements to reduce risks of morbidity and mortality. In that regard, since edible mushrooms are nutritionally rich and contains essential minerals as well as health-promoting compounds, they are a promising tool for improving the nutritional and health quality of commonly carbohydrate-rich foods.

Objective

The objective of this study was to examine the Zinc bioaccessibility and sensory properties of HMT finger millet porridge blended with Zinc-dense mushroom.

Methods

Oyster mushroom (Pleurotus ostreatus) was grown on rice straw enriched with zinc sulfate at various concentrations. After reaching full maturity, the mushrooms were harvested, dried, and milled into a fine powder. Zinc-rich mushroom powder was mixed with millet flour in various proportions and used to prepare porridge. The zinc bioaccessibility in millet-mushroom flour blends was determined using a simulation method of gastro intestinal digestion. In addition, panelists comprising of mothers and caregivers of children aged between 6 and 23 months were asked to evaluate the sensory attributes of millet-mushroom porridge.

Results

Adding Zinc to growth substrates had a significant (p˂0.05) effect on mushroom yield. Control substrates without Zinc yielded 120 g of mushroom per kilogram substrate. However, when 100 mg Zinc was added to the substrate, the yield increased by 65.6%. The study further noted that substrates with Zinc beyond 100 mg had a negative effect on mushroom yield. Consequently, substrates with the highest Zinc level (600 mg) produced the lowest mushroom yields. Increasing substrates Zinc content, on the other hand, had positive effect on mushroom Zinc levels. Substrates without Zinc produced mushrooms containing 8.9 mg Zinc, which increased by 30.9% when 600 mg Zinc was added. Furthermore, HMT finger millet porridge without mushrooms had a phytates: Zinc molar index of 60.3, which decreased to 34 when 20% (w/w) mushroom proportions were added. Despite having the highest bioaccessible Zinc with the least effect on texture and appearance, a 20% mushroom proportion in HMT finger millet porridge considerably compromised the taste, aroma and general consumer acceptability.

Conclusion

Amending HMT finger millet flour with mushroom powder improved Zinc bioaccessibility of the porridge. However, when added beyond a certain limit, mushroom reduced organoleptic qualities of the porridge, which affected overall consumer acceptance. The study recommends, therefore, that mushroom powder be added to finger millet flour in the appropriate proportions to enhance nutritional and health benefits of porridge while minimizing possible negative impacts on sensory properties.

Accumulation of pollutants from fly ash in Pleurotus ostreatus and a substrate based on coffee grounds by elemental analysis using the ICP-OES method and photometric method

The substrate mixtures were created in the study, using spent coffee grounds for Pleurotus ostreatus cultivation with the addition of straw and fluidized bed ash at 5 and 10 percent by weight relative to the total weight of coffee grounds. In order to determine the ability to accumulate heavy metals and the possibility of further waste management, analyses of micro- and macronutrients, biogenic elements, as well as the metal content of fungal fruiting bodies, mycelium and post-cultivation substrate were performed. The addition of 5 percent resulted in slower growth of mycelium and fruiting bodies, and with the addition of 10 percent, the growth of fruiting bodies was completely inhibited. The accumulation of elements such as (Cr), (Cu), (Ni), (Pb) and (Zn) was reduced in the fruiting bodies grown on the substrate with the addition of 5 percent fly ash, compared to spent coffee grounds without additives.

Integration of Physiological, Transcriptomic and Metabolomic Reveals Molecular Mechanism of Paraisaria dubia Response to Zn2+ Stress

Utilizing mycoremediation is an important direction for managing heavy metal pollution. Zn²⁺ pollution has gradually become apparent, but there are few reports about its pollution remediation. Here, the Zn²⁺ remediation potential of Paraisaria dubia, an anamorph of the entomopathogenic fungus Ophiocordyceps gracilis, was explored. There was 60% Zn²⁺ removed by Paraisaria dubia mycelia from a Zn²⁺-contaminated medium. To reveal the Zn²⁺ tolerance mechanism of Paraisaria dubia, transcriptomic and metabolomic were executed. Results showed that Zn²⁺ caused a series of stress responses, such as energy metabolism inhibition, oxidative stress, antioxidant defense system disruption, autophagy obstruction, and DNA damage. Moreover, metabolomic analyses showed that the biosynthesis of some metabolites was affected against Zn²⁺ stress. In order to improve the tolerance to Zn²⁺ stress, the metabolic mechanism of metal ion transport, extracellular polysaccharides (EPS) synthesis, and microcycle conidiation were activated in P. dubia. Remarkably, the formation of microcycle conidiation may be triggered by reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signaling pathways. This study supplemented the gap of the Zn²⁺ resistance mechanism of Paraisaria dubia and provided a reference for the application of Paraisaria dubia in the bioremediation of heavy metals pollution.

Bioprospecting the Biological Effects of Cultivating Pleurotus ostreatus Mushrooms from Selected Agro-Wastes and Maize Flour Supplements

Pleurotus mushrooms are valuable food supplements with health and environmental restorative potential. In this paper, we sought to evaluate the biological activities and profile the bioactive compounds found in Pleurotus ostreatus cultivated from agro-waste supplemented with maize flour. We investigated carbon to nitrogen (C/N), antimicrobial, antioxidant, and antimalarial potential for the varying supplementation during mushroom cultivation. GCMS was utilized for screening bioactive compounds found in P. ostreatus. Changes in supplementation directly correlate with changes in compound profiling. Nonetheless, some compounds were found to be common amongst the tested mushrooms, including pentadecanoic acid; 9,12-octadecadienoic acid, methyl ester; pentadecanoic acid, methyl ester; octadecanoic acid; and diisooctyl phthalate. The highest antimicrobial potential against Gram-positive Staphylococcus aureus was observed when maize flour supplements were increased to 12% and 18%. Our data demonstrated that the observed antioxidant (DPPH, ABTS, and reducing power) and antimicrobial activity could emanate from various supplementation conditions. Furthermore, supplementation has an impact on the mushroom yield and phytochemical profiles of the produced mushroom.

The effect of arsenic, cadmium, mercury, and lead on the genotoxic activity of Boletaceae family mushrooms present in Serbia

The aim of this study was to determine accumulation of heavy metals and metalloids which are widely distributed in the environment and in food chain using wild edible mushrooms belonging to the Boletaceae family mushrooms. In addition, methanol extracts of mushrooms were tested for in vitro protective effect by the cytochalasin-B blocked micronucleus (CBMN) assay using chromosome aberrations in human peripheral lymphocytes as a model. The genotoxic activity of methanol extracts prepared at 4 different concentrations (1, 2, 3 or 6 µg/ml) was examined using amifostine and mitomycin C as positive controls. Extracts of species B. regius and B. edulis exhibited the greatest reduction in the frequency of micronuclei (MN). Extract of B. regius at concentrations of 2 µg/ml showed the highest decrease in number of MN. In comparison, extract of mushroom B. edulis at a concentration of 3 µg/ml displayed less reduction. However, as heavy metals and metalloids are found in mushrooms, another aim was to examine whether these agents affected genotoxicity. Principal component analysis (PCA) identified clustering differences between control and heavy metals and metalloids groups and might explain the influence of heavy element content and genotoxic activity in mushrooms.

Assessment of nutrient contents and bio-functional activities of edible fungus bio-fortified with copper, lithium and zinc

Bio-enrichment of edible mushrooms is an outstanding strategy to deliver essential nutrients to human. In this study, an edible fungus; Pleurotus pulmonarius was cultivated on spent mushroom substrate (SMS) supplemented with copper, lithium, and zinc. Proximate and mineral analysis of cultivated mushroom was determined using methods of AOAC. Antimicrobial activity of cultivated mushroom was assessed against microorganisms using agar well diffusion. Antioxidant property of mushroom was assessed against free radicals. Similar (p ≤ 0.05) protein contents of 18.93%, 18.80% and 17.90% were respectively obtained in P. pulmonarius biofortified with Cu + Li + Zn, Cu + Zn and Zn. Crude fibre in element fortified-mushroom ranged from 9.02 to 10.11%, while non-fortified mushroom was 8.66%. Copper content of P. pulmonarius fortified with Cu alone and Cu + Zn were 96.12 mg/100 g and 98.09 mg/100 g, respectively. Mushroom fortified with Zn has the highest zinc content of 520.15 mg/100 g. Mushroom fortified with Li and Li + Zn have a similar (p ≤ 0.05) Li content of 106.02 mg/100 g and 104.30 mg/100 g, respectively. Extract from mushroom-fortified with copper has the highest zone of inhibition (15.1 mm) against Klebsiella pneumoniae at 1.0 mg/ml. Mushroom fortified with Cu + Li + Zn and Li + Zn, respectively have similar (p ≤ 0.05) scavenging activities of 79.10 and 81.0% against DPPH. Mushroom fortified with Zn or Zn + Cu enhanced the growth of Lactobacillus acidophilus and Lactobacillus plantarum. Antimicrobial, antioxidant and prebiotic activities of fortified-mushroom could be attributed to arrays of phytochemicals and bio-accumulated elements. Hence, bio-fortified mushrooms can be used as functional foods and as biopharmaceuticals to treat ailments associated with nutrient deficient.

Prediction models for monitoring selenium and its associated heavy-metal accumulation in four kinds of agro-foods in seleniferous area

Se-rich agro-foods are effective Se supplements for Se-deficient people, but the associated metals have potential risks to human health. Factors affecting the accumulation of Se and its associated metals in Se-rich agro-foods were obscure, and the prediction models for the accumulation of Se and its associated metals have not been established. In this study, 661 samples of Se-rich rice, garlic, black fungus, and eggs, four typical Se-rich agro-foods in China, and soil, matrix, feed, irrigation, and feeding water were collected and analyzed. The major associated metal for Se-rich rice and garlic was Cd, and that for Se-rich black fungus and egg was Cr. Se and its associated metal contents in Se-rich agro-foods were positively correlated with Se and metal contents in soil, matrix, feed, and matrix organic contents. The Se and Cd contents in Se-rich rice grain and garlic were positively and negatively correlated with soil pH, respectively. Eight models for predicting the content of Se and its main associated metals in Se-rich rice, garlic, black fungus, and eggs were established by multiple linear regression. The accuracy of the constructed models was further validated with blind samples. In summary, this study revealed the main associated metals, factors, and prediction models for Se and metal accumulation in four kinds of Se-rich agro-foods, thus helpful in producing high-quality and healthy Se-rich.

Selected fungi of the genus Lactarius - screening of antioxidant capacity, antimicrobial activity, and genotoxicity

It is well-known that mushrooms of the genus Lactarius constitute a natural food resource providing health benefits as a nutritient. This genus contains 4 mushrooms identified as L. deliciosus, L. volemus, L. sanguifluus, L. semisanguifluus and L. piperatus which were collected in Serbia. The aim of this study aimed was to identify and characterize the content of phenolic compounds and examine the antioxidant potential of 5 wild edible mushrooms. L. sanguifluus contained the highest content of total phenol compounds (75.25 mg gallic acid equivalents (GAE) per g dry extract weight (GAE/g DE) and exhibited the greatest antioxidant activity through the ability to remove radicals as evidenced by ABTS assay (8.99 mg of trolox equivalents (TE) per g dry extract weight (mg TE/g DE); total reducing power (TRP) assay mg ascorbic acid equivalents per mg of dry extract weight (0.42 mg AAE/g DE) and CUPRAC (14.23 mg TE /g DE). L. deliciosus methanolic extract produced greatest scavenging of the DPPH radical (46%). The methanol mushroom extracts were screened for in vitro antimicrobial activity against a panel of pathogenic bacterial strains using the microdilution method. Of all the extracts tested, L. sanguifluus extract showed the best antibacterial properties. The cytokinesis block micronucleus assay results for the examined mushrooms demonstrated that extracts at a concentration of 3 μg/ml decreased the number of micronuclei (MN) in the range of 19-49% which is significant bearing in mind that radioprotectant amifostine reduced the frequency of MN by only 16.3%. Data thus demonstrate that the 5 wild edible mushrooms of genus Lactarius contain constituents that are beneficial not only as nutrients but also have the potential as antioxidants, antibacterial and antigenotoxic properties.

Green Synthesis of Nanoparticles by Mushrooms: A Crucial Dimension for Sustainable Soil Management

Soil is the main component in the agroecosystem besides water, microbial communities, and cultivated plants. Several problems face soil, including soil pollution, erosion, salinization, and degradation on a global level. Many approaches have been applied to overcome these issues, such as phyto-, bio-, and nanoremediation through different soil management tools. Mushrooms can play a vital role in the soil through bio-nanoremediation, especially under the biological synthesis of nanoparticles, which could be used in the bioremediation process. This review focuses on the green synthesis of nanoparticles using mushrooms and the potential of bio-nanoremediation for polluted soils. The distinguished roles of mushrooms of soil improvement are considered a crucial dimension for sustainable soil management, which may include controlling soil erosion, improving soil aggregates, increasing soil organic matter content, enhancing the bioavailability of soil nutrients, and resorting to damaged and/or polluted soils. The field of bio-nanoremediation using mushrooms still requires further investigation, particularly regarding the sustainable management of soils.