Improvement of zinc bioaccumulation and biomass yield in the mycelia and fruiting bodies of Pleurotus florida cultured on liquid media

Accumulation of Bisphenol A® by Pleurotus spp.-Flow Injection Analysis

A specific feature of mushrooms (including those of the genus Pleurotus) is their natural ability to absorb and accumulate many chemical substances present in their immediate environment, which makes them an excellent natural sorption material. Hence, fruiting bodies of mushrooms have been recognized for years as excellent indicators of the environment, reflecting its current state. Nevertheless, mushrooms can accumulate both health-promoting substances, such as bioelements, and toxic substances, such as heavy metals and organic compounds, including bisphenol A® (BPA). This organic chemical compound in the phenol group, although it has been withdrawn in the EU since 2010, is widely present in the environment around us. In the present experiment, we aimed to determine the effect of adding BPA to liquid media for in vitro cultures of Pleurotus spp. The biomass increases were determined. Moreover, the degrees of adsorption and desorption of BPA from the obtained freeze-dried biomass in two different environments (neutral and acidic) were determined as a function of time. This is the first study to determine the bioavailability of adsorbed BPA in obtained biomass by extracting the mycelium into artificial digestive juices in a model digestive system. BPA was added to the liquid Oddoux medium in the following amounts: 0.01, 0.5, and 0.5 g/250 mL of medium. The amounts of adsorbed and desorbed BPA were determined by flow injection analysis (FIA) with amperometric detection. The addition of BPA to the substrate reduced the biomass growth in each of the discussed cases. BPA adsorption by the mycelium occurred at over 90% and depended on the morphology of the mushroom (structure, surface development, and pore size). BPA desorption depended on the pH of the environment and the desorption time. Mushrooms are an excellent natural remedial material, but BPA is extracted into artificial digestive juices; therefore, consuming mushrooms from industrialized areas may have health consequences for our bodies.

Pleurotus florida mediated biosynthesis of nanoparticles and biofortification

The mycosynthesis of biogenic NPs using nanotechnology technique is an ecofriendly and economical approach. The extracellular mycelial extract of the Pleurotus florida fungi were used to biosynthesized Zn, Cu and Fe NPs using zinc sulphate, zinc chloride, copper sulphate, copper chloride ferrous sulphate and ferric chloride, precursor salts at 1.0 mM concentration. The color of reaction mixture was changed from (transparent to white, blue to green and yellow to brown) for Zn, Cu and Fe NPs during incubation period of 96 h at 25 ± 2 °C, indicating synthesis of NPs. Spectroscopy and microscopy techniques were used for the characterization of newly synthesized biogenic NPs. Whereas, the ICP-MS analysis revealed that copper chloride precursor salts produced high concentration of Cu biogenic NPs, followed by zinc chloride derived Zn NPs. The fortification with the biogenic NPs of Pleurotus florida mycelium exhibited high accumulation of the trace elements as compared to non-fortified mycelium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01307-z.

Functional Components from the Liquid Fermentation of Edible and Medicinal Fungi and Their Food Applications in China

Functional raw materials rich in various effective nutrients and active ingredients that are of stable quality can be obtained from the liquid fermentation of edible and medicinal fungi. In this review, we systematically summarize the main findings of this comparative study that compared the components and efficacy of liquid fermented products from edible and medicinal fungi with those from cultivated fruiting bodies. Additionally, we present the methods used in the study to obtain and analyze the liquid fermented products. The application of these liquid fermented products in the food industry is also discussed. With the potential breakthrough of liquid fermentation technology and the continued development of these products, our findings can serve as a reference for further utilization of liquid fermented products derived from edible and medicinal fungi. Further exploration of liquid fermentation technology is necessary to optimize the production of functional components from edible and medicinal fungi, and to enhance their bioactivity and safety. Investigation of the potential synergistic effects of combining liquid fermented products with other food ingredients is also necessary to enhance their nutritional values and health benefits.

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.

The yield, nutritional value, umami components and mineral contents of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes

This study was carried out to evaluate the yields and quality of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes (pine, poplar, and honeysuckle rattan). The biological efficiency (BE) of the substrates varied from 61.89% to 81.01%. The total protein content, gamma-aminobutyric acid (GABA) content and equivalent umami concentration (EUC) values of the mushrooms were greatly influenced by the flush number and the substrate, however, the total sugar content and ergosterol content of the mushrooms were not significantly affected. The first-flush mushrooms that were grown on the pine sawdust-based substrate had the highest protein content, and the first-flush mushrooms that were grown on the honeysuckle rattan sawdust-based substrate had the highest GABA content and EUC values. All the mushroom samples accumulated Cu but excluded Ca, Mn, Pb, Cr, and Cd, and the concentrations of Mg, Fe, and Mn are species and flush number dependent.

Pleurotus spp. Mycelia Enriched in Magnesium and Zinc Salts as a Potential Functional Food

Worldwide, mushrooms belonging to the Pleurotus spp. such as P. citrinopileatus, P. djamor, and P. pulmonarius are highly valued not only for their taste and aroma but also for their health-promoting properties. These species are rich in bioelements, vitamins, and above all, compounds that exhibit immunostimulatory activity. Therefore, in this study, we aimed to determine the effect of the supplementation of culture media using inorganic Mg and Zn salts. This is the first study to establish the bioavailability of the selected elements (Mg and Zn) and anions (Cl⁻, SO₄²⁻) from the enriched biomass by means of the extraction of lyophilized mycelium into artificial digestive juices. The following salts were added to the liquid Oddoux medium: ZnSO₄·7H₂O, ZnCl₂, MgSO₄·7H₂O or MgCl₂·6H₂O. The bioelements, anions and organic compounds in the obtained biomass were determined. The addition of Zn and Mg salts to the media increased the production of biomass by 30% and increased the bioaccumulation of the inorganic salts. Maintaining in vitro cultures under optimized and controlled conditions produced mycelium with a better composition and health properties than otherwise. Such enriched biomass may be classified as potential functional foods, aiding in overcoming deficiencies of elements and organic compounds with biological activity in humans.

Risk Assessment of Potential Food Chain Threats from Edible Wild Mushrooms Collected in Forest Ecosystems with Heavy Metal Pollution in Upper Silesia, Poland

In this study, the contents of selected heavy metals (Zn, Cu, Cd, Pb, Cr, and Ni) and macroelements (C, N, K, P, S, Mg, Na, and Ca) were measured in wild mushrooms growing in a heavily polluted forest ecosystem in the northeastern part of the Upper Silesian Industrial Region. The research was conducted on 10 species of mushrooms belonging to three families: Boletaceae, Russulaceae, and Suillaceae. Using a spatial autoregressive model, the study showed a strong relationship between heavy metal concentrations (especially Zn, Pb, and Cd) and the distance from a source of industrial pollution (a zinc smelter, Huta Miasteczko Śląskie). The concentrations of potentially toxic metals (Pb and Cd) in mushrooms significantly exceeded food-acceptable standards. The bioconcentration factor (BCF), calculated as the ratio between the concentration in mushroom tissues and in forest soils overall, reached the highest values for cadmium (Cd). The highest accumulation capacity for Cd was noted for Imleria badia (BCF = 9.18), which was also the most abundant mushroom species in the study plots. In general, the established threshold values for Pb and Cd concentrations in consumer mushrooms and food products were exceeded up to almost 30-fold in the studied area. We conclude that the potential risk to human health of the toxic elements that enter the food chain through the harvesting and consumption of wild mushrooms from this region is significant.

Selenium and Zinc Biofortification of Pleurotus eryngii Mycelium and Fruiting Bodies as a Tool for Controlling Their Biological Activity

Pleurotus eryngii (DC:Fr.) Quel. is a cultivated mushroom of high culinary value and medicinal properties. Mycelium of P. eryngii is characterized by the ability of effective bio-elements absorption from growth media so it could be biofortified with trace elements with a functional activity in the human body. In this study, the ability of P. eryngii mycelia from in vitro cultures as well as fruiting bodies were investigated in terms of their effectiveness in zinc and selenium accumulation. The effect of Se and Zn biofortification on productivity, chemical compounds, and bio-elements content of P. eryngii was determined as well. To enhance Se and Zn content in P. eryngii fruiting bodies and mycelia, substrates were supplemented with sodium selenite, at a concentration of 50 mg L^-1, zinc sulfate, and zinc hydro-aspartate at a concentration of 87.2 and 100.0 mg L^-1, respectively. Mentioned Zn concentrations contained the same amount of zinc(II) ions, namely 20 mg L^-1. The content of organic compounds include phenolic compounds and lovastatin, which were determined by a high-performance liquid chromatography with diode-array detector (HPLC-DAD) and reverse phase high-performance liquid chromatography (RP-HPLC) method with UV detection. The ability of P. eryngii to accumulate zinc and selenium from the culture medium was demonstrated. The degree of accumulation of zinc turned out to be different depending on the type of salt used. The present study also showed that conducting mycelium of P. eryngii in in vitro culture, with a higher content of zinc ions, can result in obtaining the materials with better antioxidant ability. The results of this study can be used to develop the composition of growing media, which ensures the production of biomass with the desired composition of elements.