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.     

Effect of calcinated oyster shell powder on growth, yield, spawn run, and primordial formation of king oyster mushroom (Pleurotus eryngii)

This study was conducted to evaluate the calcium (Ca) absorption efficacy of king oyster mushroom (Pleurotus eryngii) grown on sawdust medium supplemented with Ca-sources, including oyster shell powder, and to determine the efficacy of oyster shell powder as a calcium supplement on growth, yield, spawn run and primordial formation of P. eryngii. Optimum calcination of oyster shell powder was achieved at the temperature of 620.56 °C. A 1% supplementation of oyster shell powder in sawdust medium did not suppress the mycelial growth of P. eryngii. Also the supplementation of 2% calcinated oyster shell powder to sawdust medium potentially increased the calcium content up to a level of 315.7 ± 15.7 mg/100 g in the fruiting body of P. eryngii, without extension of duration of spawn run and the retardation of the days to primordial formation. These results suggest that the shellfish by-products, including oyster shell powder, can be utilized to develop calcium enriched king oyster mushrooms.     

Mycoremediation: the study of transfer factor for plutonium and americium uptake from the ground

In our scientific research we have monitored mycoremediation’s properties of oyster mushrooms in cultivation on the soil what is contaminated by solutions with radioactive isotopes of ²³⁹Pu and ²⁴¹Am with known activity. We monitored specific activities of absorbed radionuclides in fruiting bodies and chemical forms of radionuclides which were compared to calculated specific activities of two background samples of oyster mushrooms intended for consumer purpose. We determined distributive coefficients between the ground and the fruiting body of oyster mushrooms. The average value which was obtained for the transfer factor for plutonium was 0.72 and for americium 3.97. To evaluate a quantity of absorbed radionuclides we used a method of liquid extraction. The emitting alpha radiation of alpha radionuclides was detected by spectrometry. For defining individual fractions of plutonium and americium that are contained in mushroom bodies was used the sequential leaching method.     

Mineral element content in prized matsutake mushroom (Tricholoma matsutake) collected in China

The contents of Ca, Cu, Fe, K, Mg, Mn, Na, and Zn in fruiting bodies of the highly-prized matsutake mushroom (Tricholoma matsutake) from twelve widely separated sites in Southwest China were determined using AAS. The results for dried mushrooms showed that the mean contents (mg kg^?1) of the determined elements decreased in the following order: K (440–2000), Na (150–740), Ca (90–850), Mg (90–680), Zn (20–180), Fe (13–78), Cu (0.34–45), Mn (0.09–7.6).     

Adsorption of Water on an MgSO4(100) Surface: A First‐Principles Investigation

The adsorption properties of water molecules on an MgSO₄(100) surface were investigated by using density functional theory (DFT) and supercell models. Optimized stable geometries of one and more than one water molecules adsorbed on an ideal MgSO₄(100) surface were obtained. The configurations with water molecules adsorbed on atoms of the second and third atomic layers of the MgSO₄(100) surface are quite stable. After adsorption, the separations between both the adjacent Mg atoms (R_{Mg? Mg}) and the adjacent O atoms of the surface (R_{O? O}) increase, which indicates that the MgSO₄(100) surface starts to deliquesce. In addition, water molecules are more likely to adsorb onto a defective surface rather than an ideal surface. Mulliken population analysis suggests that fewer charges transfer to the water molecule from the Mg atom of a defective substrate. Finally, Raman spectra were calculated for 0.5, 1, and 2 ML (ML=monolayer) water adsorbed on an MgSO₄(100) surface, which is helpful for further related experiments.     

Thermodynamics of the system H2O−NaCl−Na2SO4−MgSO4 to the saturation limit of NaCl at 25°C

Isopiestic results are reported for the quaternary system H₂O–NaCl–Na₂SO₄–MgSO₄. The excess free energies for mixing the double salt Na₂ Mg(SO₄)₂ with NaCl are fairly large and negative, as also are the free energies for mixing the three salts to form the quaternary aqueous system.     

Interference of salts on the determination of lead by electrothermal atomic absorption spectrometry. Ion chromatographic study

The influence of various salts on the atomization signal of lead has been examined by using a transverse heated atomic absorption spectrometer. To get more information about interference mechanisms, volatilization of salts has been studied by ion chromatographic analysis of the residue left on the furnace after drying or charring. The use of a Pd/Mg chemical modifier in these model solutions has also been examined. In 0.1 M chloride medium, NaCl, MgCl₂ and CaCl₂ do not interfere significantly. However, their different behaviour in the furnace, and particularly hydrolysis of MgCl₂ influence greatly the charring curves of Pb. The use of a Pd/Mg modifier appears interesting only in the case of NaCl. Indeed, Pd stabilizes Pb sufficiently to permit the removal of NaCl by charring. In the case of MgCl₂, Pb is not sufficiently stabilized to remove chloride through hydrolysis of MgCl₂ or volatilization of MgCl₂. In the presence of CaCl₂, the Pb signal is delayed and coincides with the background absorption signal of CaCl₂; the stabilization effect is not sufficient to eliminate CaCl₂ by charring before atomization. At 0.1 M nitrate concentration, the presence of NaNO₃, Mg(NO₃)₂, and particularly Ca(NO₃)₂, greatly modifies the atomization signal shape of Pb. Pb is more stabilized in nitrate medium, but losses are observed at the decomposition step of nitrate salts. In this medium, the stabilization effect of Pd leads to a single peak signal and permits elimination of nitrate decomposition products before atomization. Interference effects are more important in the presence of 0.1 M sulphate salts and increase with the acidity of the medium. Na₂SO₄, which is reduced to Na₂S on the graphite, does not interfere significantly. However, the decomposition products of MgSO₄ and CaSO₄ induce an important interference effect on the determination of Pb which is stabilized in the furnace. In the case of Na₂SO₄, the use of the Pd/Mg modifier delays the atomization signal which coincides with the background absorption signal, leading to an important interference effect which cannot be eliminated by charring. In the presence of MgSO₄ and CaSO₄, the stabilizing effect of Pd permits the elimination of decomposition products of sulphate salts before atomization and suppresses the chemical interference effect.     

Solid-state fermentation of agricultural wastes into food through pleurotus cultivation

The technical feasibility of using agricultural wastes (mango and date industry wastes) as a substrate for the cultivation ofPleurotus ostreatus NRRL-0366 is evaluated. When comparing the biological efficiency of mushroom production, the highest yield of fruiting bodies was obtained using a mixture of date waste and rice straw at a ratio (1:1) (11.96%), followed by a mixture 3:1 (11.16%). The lowest one was the mixture 2:1 (9.19%). FungusPleurotus ostreatus NRRL-0366 can also be cultivated on mango waste supplemented with rice straw at a different ratio. The best one was the 1:1 mixture (10.18%), whereas the lowest was a mixture 3:1 (6.4%). Comparing the results obtained favored the use of date waste as a substrate for growingPleurotus ostreatus NRRL-0366. Spawn was cultured on three different substrates as follows: Date waste alone (I); 1:1 (by wt) date waste and rice straw (II); 1:1:1 date waste, rice straw, and corncobs (III). Final dry weight and composition of the fruiting bodies are tabulated for the three sets of conditions. Date waste and rice straw mixture (II) is a good source of nonstarchy carbohydrate (67%) and protein (27.44%) containing amounts of essential amino acids, especially lysine and low RNA (3.81%). Elemental analysis were studied in the fruit bodies of the three media.     

Rosellin A and B,two red diketopiperazine alkaloids from the mushroom Mycena rosella

Rosellin A and B, two red diketopiperazine alkaloids with unprecedented structures, have been isolated from the fruiting bodies of the mushroom Mycena rosella. The structures of the rosellins were mainly deduced from their 2D NMR and HRMS (ESI) spectra. Their absolute configuration was determined by comparison of the CD spectra of the rosellins with the corresponding CD spectra obtained by quantum chemical calculations. Root exposure to rosellin A led to bleaching of the leaves of Lepidium sativum plants.     

Study of the Evaporation of a Brine Involving the System Na+, Mg2+, K+, Cl−, S 4 2− –H2O: Crystallisation of oceanic salts

The evaporation of a Tunisian brine sample involving the system Na⁺, Mg²⁺, K⁺, Cl^–, S ₄ ^2– –H₂O was studied under atmospheric pressure and at ambient temperature. The selective densities of precipitation of halite (NaCl) and of co-precipitation of halite and astrakanite (Na₂Mg(SO₄)₂·4H₂O), halite and kaïnite (MgSO₄·KCl·H₂O) and epsomite MgSO₄·7H₂O were determined.During the evaporation of the studied brine, calculations related to the hypothetical composition of the solution in terms of the simple salts NaCl, MgSO₄, KCl and MgCl₂.This revised version was published online in November 2005 with corrections to the Cover Date.     

Potential of magnesium salt–monoalkylpolyethylene glycol–water systems for use in micellar extraction

Solubilities in MgCl₂ (MgSO₄, Mg(NO₃)₂)–syntanol DS-10 (syntanol ALM-10)–water systems have been studied by the visual-polythermal method and the isothermal section method. The liquid–liquid phase separation region was shown to change its topology depending on temperature and the salting-out agent. The salting-out agent anion was shown to influence the cloud point of syntanol solutions. The effect of structure on the ability of syntanol to be salted out by magnesium salts was studied. Optimal temperature and concentration parameters of boron extraction in the studied systems were determined.     

Magnesium sulfate against oxidative damage of membrane lipids: A theoretical model

The role of magnesium sulfate as an inhibitor of lipid peroxidation has been poorly understood, although this salt has been intensively used in a wide range of diseases related to lipid peroxidation, for example, preeclampsia. Classical molecular dynamics (MD) simulations of a lipid bilayer in the presence of ^?OH radicals and MgSO₄ were performed to study their effects on membrane properties. Additionally, quantum chemistry (QC) calculations for MgSO₄, ^?OH, MgSO₄^?OH, [MgSO₄(H₂O)₄], and [MgSO₄(H₂O)₄^?OH] were performed to analyze the interactions between ^?OH^…Mg. The MD results showed that the Mg salt is hydrated, forming a contact ion pair (CIP) that is adsorbed on the membrane surface close to phosphate groups. Comparisons of MD calculations for Mg? O distances indicate good agreement with theoretical QC and experimental studies. MD results also reveal that MgSO₄ increases the thickness and the compressibility modulus of the membrane, indicating that it is less compressible. In contrast, DFT calculations show important ^?OH^…Mg? SO₄ interactions in hydrated systems that inhibit the radical action by resonance in the group (smearing the spin density). These results, together with the reported experimental findings of ^?OH high mobility in water and fast water exchange in Mg⁺², may explain the MgSO₄ protective effect against lipid peroxidation on cellular membranes.     

The phase diagrams of the systems MgCl2 + MgB6O10 + H2O and MgSO4 + MgB6O10 + H2O at 323.15 K and Pitzer model

The solubilities and the relevant physicochemical properties of the systems MgCl₂ + MgB₆O₁₀ + H₂O and MgSO₄ + MgB₆O₁₀ + H₂O at 323.15 K were determined by the method of isothermal dissolution, and the phase diagrams and the diagrams of physicochemical properties versus composition were plotted. Both of the systems belong to a simple eutectic type, and neither double salts nor solid solution were found. Based on the extended Harvie-Weare (HW) model and its temperature-dependent equations, the value of the singlesalt Pitzer parameters ??⁽⁰⁾, ??⁽¹⁾, ??⁽²⁾, and C ^? for MgCl₂, MgSO₄, and Mg(B₆O₇)(OH)₆, the mixed ion-interaction parameters $\theta _{Cl, B_6 O_{10} }$ , $\theta _{SO_4 , B_6 O_{10} }$ , $\Psi _{Mg, Cl, B_6 O_{10} }$ , $\Psi _{Mg, SO_4 , B_6 O_{10} }$ , the average equilibrium constants (lnK _aver) of solids in the systems and the Debye-Hückel parameter A ^? were fitted. Using the Pitzer parameters and the average equilibrium constants of solids at equilibrium, the solubilities of the two systems at 323.15 K have been calculated. Comparisons between the calculated and experimental results show that the predicted solubilities agree well with experimental data.     

Solid–liquid metastable equilibria in the quaternary system Li2SO4 + MgSO4 + Na2SO4 + H2O at T = 263.15 K

Solubility in the liquid–solid metastable system Li₂SO₄ + MgSO₄ + Na₂SO₄ + H₂O at T = 263.15 K was studied using the isothermal evaporation method. Based on experimental data, dry-salt phase and water-phase diagrams of the system were plotted. The dry-salt phase diagram of the system includes one three-salt co-saturation point, three metastable solubility isotherm curves, and three crystallization regions corresponding to lithium sulphate monohydrate (Li₂SO₄·H₂O), epsomite (MgSO₄·7H₂O), and mirabilite (Na₂SO₄·10H₂O). Neither a solid solution nor double salts were found. Based on the extended Harvie–Weare (HW) model and its temperature-dependent equation, the values of the Pitzer parameters β⁽⁰⁾, β⁽¹⁾, β⁽²⁾, and C^Φ for Li₂SO₄, MgSO₄, and Na₂SO₄, the mixed ion-interaction parameters θ_Li,Na, θ_Li,Mg, θ_Na,Mg, ΨLi,Na,SO₄${\Psi }_{\text{Li,Na,S}{\text{O}}_4}$, ΨLi,Mg,SO₄${\Psi }_{\text{Li,Mg,S}{\text{O}}_4}$, and ΨNa,Mg,SO₄${\Psi }_{\text{Na,Mg,S}{\text{O}}_4}$, and the Debye–Hückel parameter A^Φ in the quaternary system at 263.15 K were obtained. The solubility of the quaternary system Li₂SO₄ + MgSO₄ + Na₂SO₄ + H₂O at T = 263.15 K was also calculated. A comparison between the calculated and experimental results shows that the predicted solubility agrees well with experimental data.     

Modeling of liquid–liquid equilibrium of polyethylene glycol-salt aqueous two-phase systems—the effect of partial dissociation of the salt

The modified NRTL model proposed in the previous paper [Y.-T., Wu, D.-Q. Lin, Z.-Q. Zhu, L.-H. Mei, Fluid Phase Equilibria 124 (1996) 67–79.] is further extended to include the effect of partial dissociation of salts in polyethylene glycol (PEG)–salt aqueous two-phase systems (ATPS), and is used to calculate the liquid–liquid equilibrium phase diagrams such as PEG–(NH₄)₂SO₄ and PEG–MgSO₄ ATPS. The phase diagrams of PEG–uni-bivalent salt ATPS can be correctly represented in the cases of both complete dissociation and partial dissociation of the salt, while those of PEG–MgSO₄ ATPS can only be described in the case of partial dissociation of the salt. The analysis shows that the salts may have different existing states in the ATPS. The effect of partial dissociation of the salts on the phase diagrams should be considered, especially for systems such as PEG–MgSO₄ ATPS.     

Influence of Cu and Mn impurities on thermally stimulated luminescence studies of MgSO4 compound

Thermally stimulated luminescence (TSL) of undoped and doped MgSO₄ with activators such as Cu and Mn has been investigated which are prepared by recrystallization method. The formations of undoped and doped MgSO₄ compounds are confirmed by XRD and FTIR studies. Photoluminescence studies have been undertaken to ensure the successful incorporation of Cu and Mn impurities in the MgSO₄ host lattice. Comparison of TL intensity of the most intensive glow peak of Cu and Mn doped MgSO₄ compounds with that of undoped MgSO₄ shows that addition of Cu and Mn impurity in MgSO₄ compound enhances the TL intensity by about 2.5 and 6 times respectively. The trap parameters namely order of kinetics (b), activation energy (E), frequency factor (s) and Balarin parameter (γ) associated with the most intensive glow peak of MgSO₄:Cu and MgSO₄:Mn phosphors were determined by using isothermal decay method and glow curve shape (Chen’s) method and these parameters are in good agreement.     

Chemical and Toxicological Investigations of a Previously Unknown Poisonous European Mushroom Tricholoma terreum

The established tradition of consuming and marketing wild mushrooms has focused attention on mycotoxicity, which has become a global issue. In the present study, we describe the toxins found in a previously unknown poisonous European mushroom Tricholoma terreum. Fifteen new triterpenoids terreolides A–F ( 1 – 6 ) and saponaceolides H–P ( 8 – 16 ) were isolated from the fruiting bodies of the toxic mushroom T. terreum. Terreolides A–C ( 1 – 3 ) possessed a unique 5/6/7 trioxaspiroketal system, whereas terreolides D–F ( 4 – 6 ) possessed an unprecedented carbon skeleton. Two abundant compounds in the mushroom, saponaceolide B ( 7 ) and saponaceolide M ( 13 ), displayed acute toxicity, with LD₅₀ values of 88.3 and 63.7 mg kg^?1 when administered orally in mice. Both compounds were found to increase serum creatine kinase levels in mice, indicating that T. terreum may be the cause of mushroom poisoning ultimately leading to rhabdomyolysis.     

Phase equilibria in the Na,K,Mg,Ca‖SO4,Cl-H2O system at 25°C in the MgSO4 · 5H2O and MgSO4 · 4H2O crystallization region

Phase equilibria in the Na,K,Mg,Ca‖SO₄,Cl-H₂O system at 25°C in the MgSO₄ · 5H₂O and MgSO₄ · 4H₂O crystallization region are studied using the translation method. MgSO₄ · 5H₂O and MgSO₄ · 4H₂O, which are equilibrium phases of the system at 25°C, are each involved in two invariant points, seven monovariant curves, and nine divariant fields. Fragments of the phase equilibria diagram for the title system in the MgSO₄ · 5H₂O and MgSO₄ · 4H₂O crystallization region are constructed.     

Solid–Liquid Metastable Phase Equilibria in the Ternary System (MgCl<Subscript>2</Subscript> + MgSO<Subscript>4</Subscript> + H<Subscript>2</Subscript>O) at 323.15 K

The solubilities and the densities in the aqueous ternary system (MgCl₂ + MgSO₄ + H₂O) at 323.15 K were determined by the isothermal evaporation method. The phase diagram was drawn for this system at 323.15 K. The phase diagram consists of two invariant points, three univariant curves, and three crystallization regions corresponding to bischofite (MgCl₂ · 6H₂O), tetrahydrate (MgSO₄ · 4H₂O) and hexahydrite (MgSO₄ · 6H₂O). Neither double salts nor solid solution was found. Based on the Pitzer and Harvie–Weare (HW) model, the solubility equilibrium constants for the salts were fitted with the solubilities in this research work, and the solubilities of the ternary system at 323.15 K were calculated. Comparisons between the calculated and measured solubilities show that the predicted data agree well with the experimental results.