Enzymatically Oxidized Carbohydrates As Dicarbonyl Biobased Cross-Linkers for Polyamines.

Carbonyl cross-linkers are used to modify textiles and form resins, and are produced annually in megatonne volumes. Due to their toxicity toward the environment and human health, however, less harmful biobased alternatives are needed. This study introduces carbonyl groups to lactose and galactose using galactose oxidase from Fusarium graminearum (FgrGalOx) and pyranose dehydrogenase from Agaricus bisporus (AbPDH1) to produce four cross-linkers. Differential scanning calorimetry was used to compare cross-linker reactivity, most notably resulting in a 34 °C decrease in reaction peak temperature (72 °C) for FgrGalOx-oxidized galactose compared to unmodified galactose. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and proton nuclear magnetic resonance (1H NMR) spectroscopy were used to verify imine formation and amine and aldehyde depletion. Cross-linkers were shown to form gels when mixed with polyallylamine, with FgrGalOx-oxidized lactose forming gels more effectively than all other cross-linkers, including glutaraldehyde. Further development of carbohydrate cross-linker technologies could lead to their adoption in various applications, including in adhesives, resins, and textiles.

Anti-Photodamage Effect of Agaricus blazei Murill Polysaccharide on UVB-Damaged HaCaT Cells.

UVB radiation is known to induce photodamage to the skin, disrupt the skin barrier, elicit cutaneous inflammation, and accelerate the aging process. Agaricus blazei Murill (ABM) is an edible medicinal and nutritional fungus. One of its constituents, Agaricus blazei Murill polysaccharide (ABP), has been reported to exhibit antioxidant, anti-inflammatory, anti-tumor, and immunomodulatory effects, which suggests potential effects that protect against photodamage. In this study, a UVB-induced photodamage HaCaT model was established to investigate the potential reparative effects of ABP and its two constituents (A1 and A2). Firstly, two purified polysaccharides, A1 and A2, were obtained by DEAE-52 cellulose column chromatography, and their physical properties and chemical structures were studied. A1 and A2 exhibited a network-like microstructure, with molecular weights of 1.5 × 104 Da and 6.5 × 104 Da, respectively. The effects of A1 and A2 on cell proliferation, the mitochondrial membrane potential, and inflammatory factors were also explored. The results show that A1 and A2 significantly promoted cell proliferation, enhanced the mitochondrial membrane potential, suppressed the expression of inflammatory factors interleukin-1ß (IL-1ß), interleukin-8 (IL-8), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), and increased the relative content of filaggrin (FLG) and aquaporin-3 (AQP3). The down-regulated JAK-STAT signaling pathway was found to play a role in the response to photodamage. These findings underscore the potential of ABP to ameliorate UVB-induced skin damage.

[Research progress on structures, activities, and biosynthesis of blazeispirol compounds from Agaricus blazei].

Agaricus blazei is a rare medicinal and edible fungus with a crispy taste and delicious flavor. Both fruiting body and mycelium are rich in polysaccharides, sterols, terpenoids, peptides, lipids, polyphenols, and other active ingredients, which have strong pharmacological activities such as anti-tumor, lipid-lowering, glucose-lowering, immunomodulation, optimization of intestinal flora, and anti-oxidation. Therefore, it is a kind of fungal resource with a great prospect of edible and medicinal development. Among the reported chemical components of A. blazei, blazeispirol is a series of sterol compounds unique to A. blazei, which has a spiral structure and is different from classical steroids. It is an important active ingredient found in the mycelium of A. blazei and has significant hepatoprotective activity. It can be used as a phylogenetic and chemotaxonomic marker of A. blazei strains and is considered an excellent lead compound for drug development. According to the skeleton structure characteristics, the 17 discovered blazeispirol compounds can be divided into two types: blazeispirane and problazeispirane. In order to further explore the resource of blazeispirol compounds of A. blazei, the discovery, isolation, structure, biological activity, and biosynthetic pathways of blazeispirol compounds of A. blazei were systematically reviewed. Besides, the metabolic regulation strategies related to the fermentation synthesis of blazeispirol A by A. blazei were discussed. This review could provide a reference for the efficient synthesis and development of blazeispirol compounds, the research and development of related drugs and functional foods, and the quality improvement of A. blazei and other medicinal and edible fungi resources and derivatives.

Bacterial interactions with the mycelium of the cultivated edible mushrooms Agaricus bisporus and Pleurotus ostreatus.

The cultivated edible mushrooms Agaricus bisporus and Pleurotus ostreatus are valuable food crops and an important source of human nutrition. Agaricus bisporus is the dominant cultivated species in the western hemisphere and in Australia, while in Asian countries P. ostreatus is more prevalent. These two mushroom species are grown on fermented-pasteurized substrates, and bacteria and fungi play an important role in converting feedstocks into a selective medium for the mushroom mycelium. The mushrooms are usually introduced to the substrate as grain spawn, and the actively growing hyphae form a range of direct interactions with the diverse bacterial community in the substrate. Of these interactions, the most well studied is the removal of inhibitory volatile C8 compounds and ethylene by pseudomonads, which promotes mycelium growth and stimulates primordia formation of both A. bisporus and P. ostreatus. Bacterial biomass in the substrate is a significant nutrition source for the A. bisporus mycelium, both directly through bacteriolytic enzymes produced by A. bisporus, and indirectly through the action of extracellular bacterial enzymes, but this is less well studied for P. ostreatus. Apart from their role as a food source for the growing mycelium, bacteria also form extensive interactions with the mycelium of A. bisporus and P. ostreatus, by means other than those of the removal of inhibitory compounds. Although several of these interactions have been observed to promote mycelial growth, the proposed mechanisms of growth promotion by specific bacterial strains remain largely uncertain, and at times conflicting. Bacterial interactions also elicit varying growth-inhibitory responses from A. bisporus and P. ostreatus. This review explores characterized interactions involving bacteria and A. bisporus, and to a lesser degree P.ostreatus, and whilst doing so identifies existing research gaps and emphasizes directions for future work.

Leveraging the 3-Chloro-4-fluorophenyl Motif to Identify Inhibitors of Tyrosinase from Agaricus bisporus.

Tyrosinase (EC 1.14.18.1) is implicated in melanin production in various organisms. There is a growing body of evidence suggesting that the overproduction of melanin might be related to several skin pigmentation disorders as well as neurodegenerative processes in Parkinson's disease. Based on this consideration, the development of tyrosinase inhibitors represents a new challenge to identify new agents in pharmaceutical and cosmetic applications. With the goal of identifying tyrosinase inhibitors from a synthetic source, we employed a cheap and facile preliminary assay using tyrosinase from Agaricus bisporus (AbTYR). We have previously demonstrated that the 4-fluorobenzyl moiety might be effective in interactions with the catalytic site of AbTYR; moreover, the additional chlorine atom exerted beneficial effects in enhancing inhibitory activity. Therefore, we planned the synthesis of new small compounds in which we incorporated the 3-chloro-4-fluorophenyl fragment into distinct chemotypes that revealed the ability to establish profitable contact with the AbTYR catalytic site. Our results confirmed that the presence of this fragment is an important structural feature to improve the AbTYR inhibition in these new chemotypes as well. Furthermore, docking analysis supported the best activity of the selected studied compounds, possessing higher potency when compared with reference compounds.

Isolation and Identification of Chemical Compounds from Agaricus blazei Murrill and Their In Vitro Antifungal Activities.

This study explores the antifungal properties of Agaricus blazei Murrill, a valuable medicinal and edible fungus. Six compounds (1-6) were first isolated from A. blazei using various isolation techniques and identified using spectroscopic methods. These compounds include linoleic acid, 1,1'-oxybis(2,4-di-tert-butylbenzene), glycerol monolinoleate, volemolide (17R)-17-methylincisterol, (24s)-ergosta-7-en-3-ol, and dibutyl phthalate. This study also assesses the antifungal activities of these compounds against Trichophyton mentagrophology, Trichophyton rubrum, Candida albicans, and Cryptococcus neoformans. The results demonstrate varied sensitivities against these pathogenic fungi, with compound 2 showing significant inhibition against T. mentagrophology, compound 3 showing significant inhibition against T. rubrum, and compound 6 showing significant inhibition against C. albicans. This study underscores the medicinal potential of A. blazei as an antifungal agent and sheds light on its valuable research implications.

Fermentation of Agaricus bisporus for antioxidant activity: response surface optimization, chemical components, and mechanism.

Agaricus bisporus is one of the most widely cultivated edible mushrooms in the world. The chemical components of A. bisporus have a wide range of biological activities. In order to deeply understand the antioxidant properties of A. bisporus, this study conducted an investigation on the components of A. bisporus fermentation. Through the single factor experiment and response surface optimization, it was found that when the C/N ratio was 45:1, the inoculum concentration was 10%, and the fermentation time was 7 d, the n-butanol extract of the fermentation product had the strongest scavenging capacity for free radical generated through 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS·+). The concentration for 50% of the maximal effect (EC50) was 0.33 ± 0.01 mg/mL. Moreover, in order to identify the two main components, the elution-extrusion counter-current chromatography (EECCC) was employed for separation, where 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) and 5-(butoxymethyl) furfural were obtained. The antioxidant activity of 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) (EC50 = 0.26 ± 0.01 mg/mL) was superior to that of 5-butylmethyl furfural (EC50 = 1.52 ± 0.02 mg/mL), indicating that 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) was the main antioxidant in the fermentation products. The thermodynamic parameters and frontier molecular orbitals of 5,5'-oxy-dimethyl-bis (2-furanaldehyde) was evaluated by density functional theory (DFT). The result indicated 5,5'-oxy-dimethyl-bis(2-furanaldehyde) scavenged free radicals in polar media through single electron transfer followed by proton transfer (SET-PT).

Anti-phytopathogenic-bacterial fatty acids from the mycelia of the edible mushroom Agaricus blazei.

Five compounds including a new compound (1) were isolated from mycelia of a mushroom-forming fungus Agaricus blazei. Compound 2 was isolated from nature for the first time. Their structures were determined by the interpretation of spectroscopic data. In the bioassay examining growth inhibitory activity against phytopathogenic bacteria Clavibacter michiganensis, Burkholderia glumae, and Peptobacterium carotovorum, all the compounds showed inhibition effects on C. michiganensis. Compounds 3 and 4 also showed weak inhibitory activity against growth of B. glumae.

Effect of moisture-controlled packaging treatment with acid-modified expanded vermiculite-calcium chloride on the quality of fresh mushrooms (Agaricus bisporus) during low-temperature storage.

BACKGROUND: Fresh mushrooms (Agaricus bisporus) are highly perishable and easily lose quality during storage. The packaging system can retard the deterioration of fresh mushrooms. However, water vapor transmission rates of commodity plastic films are lower than the transpiration rate of mushrooms, resulting in increased moisture condensation in the package and perishability of mushrooms due to microbial growth. A possible solution for controlling the humidity level in the package is to use a hygroscopic material. Acid leaching can improve the chemical and physical properties of expanded vermiculite (EV). The aim of this study was to develop a novel hygroscopic agent from acidified expanded vermiculite (AEV) and calcium chloride (CaCl2 ) that has a high moisture absorption capacity and maintains a powdered form in the packaging system for fresh mushrooms. RESULTS: Our findings revealed that leaching EV with hydrochloric acid increased porosity and hydrophilicity. The combination of AEV:CaCl2 at 6:4 (w/w, AEV/CS40) showed the highest moisture adsorption capacity at 1.724 ± 0.03 g water per gram of material. Then, 1.55 g of AEV/CS40 was applied to the mushroom packaging and stored at 4 °C. The results indicated that AEV/CS40 could delay mushroom deterioration in terms of color change, firmness, pH, total soluble solids, and microbial growth. CONCLUSION: The study findings indicate that the alternative solid hygroscopic material obtained by combining AEV with CaCl2 has potential for use as a hygroscopic material for preserving the quality of white button mushrooms. © 2021 Society of Chemical Industry.

UV-C treatment inhibits browning, inactivates Pseudomonas tolaasii and reduces associated chemical and enzymatic changes of button mushrooms.

BACKGROUND: Button mushrooms with completely white appearance are popular with consumers. However, button mushrooms are susceptible to infection with Pseudomonas tolaasii, which results in browning. This study evaluates the effects of ultraviolet-C (UV-C) treatment on the inactivation of P. tolaasii in vitro and in vivo and on the physiological and chemical changes of button mushrooms during storage for 21 days at 4 °C. RESULTS: UV-C doses of 0.5 to 9.0 kJ m-2 resulted in 3.91-6.26 log CFU mL-1 reduction of P. tolaasii populations in vitro, and UV-C treatment reduced P. tolaasii populations inoculated on mushroom cap surfaces and browning severity. Moreover, P. tolaasii increased polyphenol oxidase (PPO) activity, and decreased phenylalanine ammonia-lyase (PAL) activity, the accumulation of phenolics and contents of brown melanin precursors, including γ-l-glutaminyl-4-hydroxybenzene (GHB), γ-l-glutaminyl-3,4-dihydroxybenzene (GDHB), and tyrosine in button mushrooms. UV-C treatment was found to reduce the negative changes due to P. tolaasii infection. CONCLUSION: These results indicated that the application of UV-C treatment inhibited browning, inactivated P. tolaasii and reduced P. tolaasii - associated chemical and enzymatic changes of button mushrooms. © 2021 Society of Chemical Industry.

Pretreatment with high oxygen controlled atmosphere enhanced fresh-cut white mushroom (Agaricus bisporus) quality via activating wounding stress defenses.

BACKGROUND: High oxygen treatment has been proven to be effective in fresh-cut white mushroom preservation, however, the preservation effect and possible mechanisms in high oxygen controlled atmosphere pretreatment (HOCAP) on wounding stress are incompletely understood. RESULTS: In this study, based on the time chosen of HOCAP research, whole white mushrooms treated with 3 h HOCAP (80% O2 + 20% CO2 ) and the wounding resistant responses of their slices were mainly investigated through phenylpropane pathway, reactive oxygen species (ROS) scavenging system, and ascorbate-glutathione (AsA-GSH) cycle. Results showed that 3 h HOCAP can induce the production of hydrogen peroxide (H2 O2 ) and superoxide anion (O2 -• ) in the early stage, as well as the NADPH oxidase activity. Enzymes and endogenous antioxidants involved in ROS scavenging were enhanced by HOCAP during the whole storage. Besides, HOCAP maintained high level of phenylalanine ammonia-lyase (PAL) activity, enhanced the content of total phenolic and lignin, accelerated the AsA-GSH cycle. CONCLUSION: The results demonstrated that HOCAP induced defense responses by increasing the ROS in the early stage which stimulated the activities of ROS scavenging enzymes, along with the capability of increasing for wounding stress defense and resistance. This study provides a theoretical pretreatment technology for fresh-cut white mushroom preservation. © 2021 Society of Chemical Industry.

Effect of diet enriched with Agaricus bisporus polysaccharides (ABPs) on antioxidant property, innate-adaptive immune response and pro-anti inflammatory genes expression in Ctenopharyngodon idella against Aeromonas hydrophila.

The effect of Agaricus bisporus polysaccharides (ABPs) supplemented diet on growth rate, antioxidant capacity, innate-adaptive immune response, proinflammatory and antiinflammatory genes expression in Ctenopharyngodon idella against Aeromonas hydrophila is reported. In both normal and challenged groups fed with 1.0 and 1.5 mg kg-1 ABPs diets resulted in a significant weight gain and feed intake. The survival was 100% in normal fish fed without or with any ABPs diet; the challenged fish fed with 1.0 mg kg-1 ABPs diet had 98.6% survival. The RBC and WBC counts, Hb, and Hct levels were significant in both normal and challenged groups fed with 1.0 and 1.5 mg kg-1 ABPs diets. A significant increase in total protein and albumin level was observed in both groups fed with 1.0 and 1.5 mg kg-1 ABPs diets. Significant increase in GPx, ROS, GR, GSH, PC, and MnSOD activity was observed in HK of both groups fed with 1.0 and 1.5 mg kg-1 ABPs diets; similarly both groups when fed with the same ABPs diets showed significant Lz, C3, and C4 activity. However, both groups fed with 1.0 mg kg-1 ABPs diet showed significant ß-defensin, LEAP-2A, IL-6, and NF-κB P65 mRNA expression. Similarly, IFN-γ2, IL-10, and TNFα mRNA expressions were significant in both groups fed with 1.0 mg kg-1 ABPs diet. The results indicate that both normal and challenged C. idella fed with a 1.0 mg kg-1 ABPs diet had better growth, antioxidant status, immune response, and pro-anti-inflammatory gene modulation against A. hydrophila.

Agaricus bisporus-Derived Glucosamine Hydrochloride Facilitates Skeletal Injury Repair through Bmp Signaling in Zebrafish Osteoporosis Model.

Glucosamine hydrochloride (GAH), one of the most basic and important derivatives of chitin, is obtained by hydrolysis of chitin in concentrated hydrochloric acid. At present, little is known about how GAH functions in skeletal development. In this report, we demonstrate that GAH, extracted from the cell wall of Agaricus bisporus, acts in a dose-dependent manner to promote not only cartilage and bone development in larvae but also caudal fin regeneration in adult fish. Furthermore, GAH treatment causes a significant increase in expression of bone-related marker genes, indicating its important role in promoting skeletal development. We show that in both larval and adult osteoporosis models induced by high iron osteogenic defects are significantly ameliorated after treatment with GAH, which regulates expression of a series of bone-related genes. Finally, we demonstrate that GAH promotes skeletal development and injury repair through bone morphogenetic protein (Bmp) signaling, and it works at the downstream of the receptor level. Taken together, our findings not only provide a strong research foundation and strategy for the screening of natural osteoporosis drugs and product development using a zebrafish model but also establish the potential for the development of Agaricus bisporus-derived GAH as a new drug for osteoporosis treatment.

Chemically Sulfated Polysaccharides from Agaricus blazei Murill: Synthesis, Characterization and Anti-HIV Activity.

AIDS, caused by HIV-1, is one of the most dangerous infectious diseases in the world. Therefore, it is necessary to develop new drugs with more potent bioactivities, less toxicity and higher tolerability for controlling the viral load, particularly by using the raw materials that are widely available. Agaricus blazei Murill (AbM), known in China as jisongrong, is of great importance as a food source and as a health-promoting supplement for immunomodulation. The polysaccharides of AbM exhibit various biological activities, such as regulating cellular immunity and providing anti-oxidative, anti-infective, and anti-inflammatory effects. At present, to our knowledge, no report has explored the chemically sulfated and anti-HIV-1 activity of AbM polysaccharides. Herein, the sulfated AbM polysaccharides with different sulfur contents were prepared by the chlorosulfonic acid-pyridine method. The characteristics of sulfated derivatives were established by the determination of the sulfur content, the relative molecular weight, and the Fourier-transform infrared spectroscopy. The anti-HIV activities of the sulfated AbM polysaccharides were evaluated by CCK-8 and the single-cycle pseudovirus infection (TZM-bl) assay. The sulfated AbM polysaccharides had strong antiviral properties, and the half-maximal inhibitory concentrations approached that of the positive control, azidothymidine. Sulfated modification of AbM polysaccharides can increase their anti-HIV pharmacological activity, which makes them promising alternative candidates as bioactive macromolecules for biomedical applications in HIV/AIDS.

On the Identification and Quantification of Ergothioneine and Lovastatin in Various Mushroom Species: Assets and Challenges of Different Analytical Approaches.

In recent years, mushrooms have drawn the attention of agro-industries and food-industries as they were considered to be valuable natural sources of health promoting compounds such as ß-glucans, ergothioneine, and lovastatin. The detection and quantification of such compounds by implementing reliable analytical approaches is of the utmost importance in order to adjust mushrooms' cultivation conditions and maximize the production in different species. Toward this direction, the current study focuses on the comparison of ultraviolet-visible (UV-Vis) spectrometry and liquid chromatography-mass spectrometry (LC-MS) methods (a) by evaluating the content of ergothioneine and lovastatin in mushrooms and (b) by highlighting any possible substrate-based interferences that hinder the accurate determination of these two compounds in order to propose the technique-of-choice for a standardized bioactive compounds monitoring. For this purpose, mushrooms produced by three species (i.e., Agaricus bisporus, Pleurotus ostreatus, and P. citrinopileatus) on various cultivation substrates, namely wheat straw (WS), winery (grape marc (GM)), and olive oil (OL) by-products, were examined. Among the two applied techniques, the developed and validated LC-MS methods, exhibiting relatively short analysis time and higher resolution, emerge as the methods-of-choice for detecting ergothioneine and lovastatin in mushrooms. On the contrary, UV-Vis methods were hindered due to co-absorbance of different constituents, resulting in invalid results. Among the studied mushrooms, P. citrinopileatus contained the highest amount of ergothioneine (822.1 ± 20.6 mg kg-1 dry sample), whereas A. bisporus contained the highest amounts of lovastatin (1.39 ± 0.014 mg kg-1 dry sample). Regarding the effect of different cultivation substrates, mushrooms produced on OL and WS contained the highest amount of ergothioneine, while mushrooms deriving from GM-based substrates contained the highest amount of lovastatin.

Onion juice and extracts for the inhibition of enzymatic browning mechanisms in frozen Agaricus bisporus mushrooms.

BACKGROUND: The potential of onion juice, as well as extracts of waste (tunic) (5%) and fleshy scale leaves (25%), to inhibit enzymatic browning of frozen Agaricus bisporus was investigated. The onion materials were used for blanching and their effectiveness in conserving integrity and appearance of mushroom fruiting bodies was compared with the currently accepted method of blanching in a sodium metabisulfite (SM) solution. RESULTS: It was observed that l-phenylalanine content may be a useful indicator of the changes in enzymatic activity during frozen storage, and l-tyrosine may be an indicator of a loss of lightness in color (parameter L*). The enzymes responsible for color changes were mainly monophenolase (MON) and, to a lesser degree, diphenolase (DIP). After being stored frozen for 8 months, these enzymes were detected at a 29:1 (DIP:MON) ratio in untreated mushrooms and a 2:1 (DIP:MON) ratio in mushrooms treated with onion juice. CONCLUSION: Onion products may be a good alternative to an SM solution. The most effective method to conserve the light color of fruiting bodies was blanching in juice or in an extract of the fleshy scale leaves. The least effective inhibitor of MON was tunic extract, which did, however, cause a favourable increase in the reducing capacity (total polyphenols) and flavonoids. Although the onion waste (tunic) extract changed the color of mushrooms from white to creamy orange, the color of these products was attractive and positively evaluated by panellists. © 2020 Society of Chemical Industry.

Effect of conservation methods on the bioaccessibility of bioelements from in vitro-digested edible mushrooms.

BACKGROUND: The release of bioelements from edible mushrooms (Agaricus bisporus, Cantharellus cibarius, and Imleria badia) was examined using in vitro simulated gastrointestinal digestion to assess their health-promoting potential. The following samples were tested: fresh, frozen, dried in a food dryer, dried in the sun, and lyophilized. The samples were incubated in gastric juice (pepsin, NaCl, HCl) and in intestinal juice (NaHCO3 , pancreatin, bile salts) with the aim of verifying the bioaccessibility of the bioelements and the digestibility of mushrooms. Four bioelements that are essential for the human body were studied: Mg, Zn, Cu, and Fe. RESULTS: It was found that Mg was extracted in the highest amounts from the sun-dried A. bisporus (1.620 g kg-1 d.w.). In the case of microelements, the lyophilized fruiting bodies of I. badia released Zn in the highest quantities (0.180 g kg-1 d.w.). Lyophilization and sun-drying methods were more advantageous than other methods. Fresh material was a more valuable source of bioelements than frozen material. CONCLUSION: Our results showed that edible mushrooms have a high content of bioelements that are easily bioaccessible, which indicates their health-promoting properties. © 2020 Society of Chemical Industry.

Valorization of dietary edible mushrooms waste: chemical and physical properties, nutrient digestibility, microbial protein synthesis and nitrogen balance in sheep.

BACKGROUND: The optimal use of feed resources must be considered by most livestock farmers. The use of low-cost agricultural by-products and the processing of these materials is one possible solution in this respect. One such compound is edible button mushroom waste (EM), a large amount of which is produced annually in the mushroom production cycle worldwide. RESULTS: Bulk density 100 of EM was smaller than the other groups. These changes also applied to alfalfa for bulk density, which was higher than the replaced waste. The dry matter solubility of EM was higher than that of alfalfa hay, whereas the ash solubility rate for EM was greater compared to alfalfa. Replacing up to 210 g kg-1 alfalfa with EM did not affect the production of purine derivatives, microbial protein, nitrogen excreted in urine and feces, and retained nitrogen, although the organic matter digestibility (OMD) increased, whereas the crude protein digestibility and neutral detergent fiber (NDF) decreased (P < 0.05). Fermentation potential, gas production rate, metabolizable energy and short-chain fatty acids were increased. On replacing up to 210 g kg-1 alfalfa with EM, the diet OMD increased, whereas the crude protein and NDF digestibility decreased (P < 0.05). CONCLUSION: EM usage in the experimental diets did not affect the production of purine derivatives, microbial protein, nitrogen excreted in urine and feces, and retained nitrogen. The physical properties, chemical composition and nutritional value of EM, as well as its low cost, show that it can be used as an alternative part of the diet forage in the ruminant's diet. © 2021 Society of Chemical Industry.

Comparison of QuEChERS and "dilute and shoot" extraction methods for multi-mycotoxin analysis of samples from button mushroom (Agaricus bisporus) cultivation.

Several components of mushroom compost (wheat straw, chicken manure) can be contaminated with mycotoxins posing food health risks to mushroom consumers. To assess the relevance of such contaminations high-throughput analytical methods are needed. In this study, two sample preparation approaches, dilute & shoot (D&S) and modified citrate buffered Quick, Easy, Cheap, Effective, Rugged, Safe (QuEChERS) were compared in terms of extraction efficiency and matrix effect in case of 13 mycotoxins in complex matrices-wheat straw, the growing media and button mushrooms (Agaricus bisporus)-of mushroom cultivation using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). D&S method resulted in recoveries of LB medium, button mushroom and compost for ≥60% in case of all investigated mycotoxins except for DON-3G. However, using modified citrate buffered QuEChERS with 2% acidification of the extraction solvent showed the complete loss of strongly polar DON-3G and fumonisin B1 (FB1). The investigated matrices had suppressive effect on ionization in all target mycotoxins except for FB1. Regarding the use of isotopologues to compensate matrix effect, even U-[13C15]-DON and U-[13C24]-T-2 can also be used to quantify their related metabolites in the studied matrices, using internal standard method.

Relationship of Agaricus bisporus mannose-binding protein to lectins with ß-trefoil fold.

Agaricus bisporus mannose-binding protein (Abmb) was discovered as part of the mushroom tyrosinase (PPO3) complex, but its function in the mushroom has remained obscure. The protein has a ß-trefoil structure that is common for Ricin-B-like lectins. Indeed, its closest structural homologs are the hemagglutinin components of botulinum toxin (HA-33) and the Ricin-B-like lectin from Clitocybe nebularis (CNL), both of which bind galactose, and actinohivin, a recently discovered mannose-binding lectin from actinomycetes. Here we show that Abmb is evolutionarily related to them, which are lectins with a ß-trefoil fold. We also show for the first time that Abmb can exhibit typical lectin agglutination activity but only when in the complex with mushroom tyrosinase. This is unexpected and unique because the two proteins are not evolutionarily related and have different activities. Lectin and tyrosinase major role in defense mechanism as well as Abmb and PPO3 gene regulation during the early stages of the development of mushroom fruiting bodies suggested that Abmb has likely a function in defense against bacterial infection and/or insect-induced damage.