Chemical and Antioxidant Properties of Wild Edible Mushrooms from Native Nothofagus spp. Forest, Argentina

Nutritional value, elemental bioaccumulation and antioxidant activity of fruiting bodies and mycelial cultures of an unrecorded wild Lactarius hatsudake from Nanyue mountainous region in China

An unrecorded wild mushroom Lactarius hatsudake from Nanyue mountainous region in China was identified. Subsequently, comparative investigation on the nutritional value, elemental bioaccumulation, and antioxidant activity was performed in the fruiting body (FB) and mycelium (MY) samples of this species. It revealed that the contents of moisture (87.66 ± 0.16 g/100 g fw) and ash (6.97 ± 0.16 g/100 g dw) were significantly higher in FB, and the total carbohydrate, fat, and protein concentrations of FB were similar to those in MY. Among nutritionally important elements, FB possessed higher concentrations of potassium (37808.61 ± 1237.38 mg/kg dw), iron (470.69 ± 85.54 mg/kg dw), and zinc (136.13 ± 5.16 mg/kg dw), whereas MY was a better source of magnesium (1481.76 ± 18.03 mg/kg dw), calcium (2203.87 ± 69.61 mg/kg dw), and sodium (277.44 ± 22.93 mg/kg dw). According to the health risk estimation, FB might pose an aluminum-related health problem when a prolonged period of exposure, while MY was risk-free for consumers. The results of antioxidant capacity (1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays) in FB and MY were within the range of 104.19 ± 5.70 mg ascorbic acid equivalents (AAE)/g to 169.50 ± 4.94 mg AAE/g, and half maximal effective concentration EC50 values ranged from 0.23 ± 0.01 mg/mL to 0.62 ± 0.05 mg/mL. The aqueous extracts of MY demonstrated a strong ABTS radical scavenging capacity with the highest AAE value.

Antioxidant Properties, Bioactive Compounds Contents, and Chemical Characterization of Two Wild Edible Mushroom Species from Morocco: Paralepista flaccida (Sowerby) Vizzini and Lepista nuda (Bull.) Cooke

Mushrooms have been consumed for centuries and have recently gained more popularity as an important source of nutritional and pharmaceutical compounds. As part of the valorization of mushroom species in northern Morocco, the current study aimed to investigate the chemical compositions and antioxidant properties of two wild edible mushrooms, Paralepista flaccida and Lepista nuda. Herein, the bioactive compounds were determined using spectrophotometer methods, and results showed that the value of total phenolic content (TPC) was found to be higher in P. flaccida (32.86 ± 0.52 mg) than in L. nuda (25.52 ± 0.56 mg of gallic acid equivalents (GAEs)/mg of dry methanolic extract (dme)). On the other hand, the value of total flavonoid content (TFC) was greater in L. nuda than in P. flaccida, with values of 19.02 ± 0.80 and 10.34 ± 0.60 mg of (+)-catechin equivalents (CEs)/g dme, respectively. Moreover, the ascorbic acid, tannin, and carotenoids content was moderate, with a non-significant difference between the two samples. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis allowed the identification and quantification of thirteen individual phenolic compounds in both P. flaccida and L. nuda, whereas p-Hydroxybenzoic acid was recognized as the major compound detected, with values of 138.50 ± 1.58 and 587.90 ± 4.89 µg/g of dry weight (dw), respectively. The gas chromatography-mass spectrometry (GC-MS) analysis of methanolic extracts of P. flaccida and L. nuda revealed the presence of sixty-one and sixty-six biomolecules, respectively. These biomolecules can mainly be divided into four main groups, namely sugars, amino acids, fatty acids, and organic acids. Moreover, glycerol (12.42%) and mannitol (10.39%) were observed to be the main chemical compositions of P. flaccida, while L. nuda was predominated by linolelaidic acid (21.13%) and leucine (9.05%). L. nuda showed a strong antioxidant property, evaluated by DPPH (half maximal effective concentration (EC₅₀) 1.18-0.98 mg/mL); β-carotene bleaching (EC₅₀ 0.22-0.39 mg/mL); and reducing power methods (EC₅₀ 0.63-0.48 mg/mL), respectively. These findings suggested that both mushrooms are potential sources of various biomolecules, many of which possess important biological activities which are interesting for the foods and pharmaceuticals industry.

Study on Phenolic and Organic Acid Compositions and Antioxidant and Enzyme Inhibition Activities of Agaricomycetes Mushroom Species from Turkey

Mushrooms stand out as one of nature's best gifts among the natural product sources with their diversity, therapeutic values and increasing popularity. In this study, antioxidant (ABTS·+ scavenging, β-carotene-bleaching, cupric-reducing antioxidant capacity (CUPRAC), DPPH· scavenging, and metal chelating assays), and enzyme (buty-rylcholinesterase (BChE) and acetylcholinesterase (AChE), α-amylase and α-glucosidase) inhibition activities of the extracts obtained from Coprinus comatus (O.F. Müll.) Pers., Cerrena unicolor (Bull.) Murrill, Inocutis rheades (Pers.) Fiasson & Niemela and Leptoporus mollis (Pers.) Quél. mushroom species were investigated. The presence of phenolic and organic acid compounds associated with the bioactive properties of the mushroom species was determined by HPLC-DAD. Fumaric acid was found to be prominent compound in C. comatus (43.90 µg/g dw) and C. unicolor (659.9 µg/g dw), vanillin in L. mollis (19.48 µg/g dw), and p-coumaric acid in I. rheades (21.32 µg/g dw). L. mollis methanol extract, as well as higher antioxidant activity than the standards in CUPRAC and β-carotene-bleaching assays, was noted as superior antioxidant active in all assays (except metal chelating). C. comatus possessed the highest inhibition activity on α-amylase (IC50: 0.23 mg/mL for methanol extract), AChE (IC50: 125.50 µg/mL for hexane extract), and BChE (IC50: 61.03 µg/mL for methanol extract). Also, C. comatus methanol (IC50: 0.09 mg/mL) and L. mollis hexane (IC50 : 0.11 mg/ mL) extracts were better α-glucosidase inhibition active than the acarbose (IC50: 0.37 mg/mL). Our study ascertained that the studied mushroom species are particularly sources of biochemically active compounds with therapeutic potential.

Nutritional Composition and Bioactive Properties of Wild Edible Mushrooms from Native Nothofagus Patagonian Forests

Nothofagus forests of the Andean Patagonian region are home to numerous wild edible mushroom (WEM) species with interesting organoleptic characteristics, although many of them have unknown nutritional and nutraceutical profiles. The proximal composition, fatty and organic acids, soluble sugars, phenolic compounds, ergosterol, as well as antioxidant and antimicrobial activity of 17 WEMs were analyzed. Carbohydrates, the most abundant macronutrients, varied between 49.00 g/100 g dw (C. magellanicus) and 89.70 g/100 g dw (F. antarctica). Significantly higher values were found for total fat in G. gargal (5.90 g/100 g dw) followed by A. vitellinus (4.70 g/100 g dw); for crude protein in L. perlatum (36.60 g/100 g dw) followed by L. nuda (30.30 g/100 g dw); and for energy in G. gargal (398 Kcal/100g) and C. hariotii (392 Kcal/100g). The most effective extracts regarding the TBARS antioxidant capacity were those of Ramaria. This is the first time that a study was carried out on the chemical composition of G. sordulenta, C. xiphidipus, F. pumiliae, and L. perlatum. The promotion of sustainable use of WEMs, including their incorporation in functional diets that choose WEMs as nutritious, safe, and healthy foods, and their use in an identity mycogastronomy linked to tourism development, requires the detailed and precise nutritional and nutraceutical information of each species.

The antioxidant potential of different edible and medicinal mushrooms

Mushroom consumption has grown extraordinarily owing to their high nutritional value, desirable taste, and aroma. Mushrooms continue generating lots of interest chiefly in their consumption as food, as a cure for different ailments, as well as important goods for commerce throughout the globe owing to their dietary, antioxidant, and therapeutic values. Higher Ascomycetes and Basidiomycetes mushrooms have different properties with anticancer and immunological potential. They as well provide vital health benefits and display a wide-ranging continuum of pharmacological effects. The antioxidant activity of different mushrooms was reviewed for different radicals including DPPH, ABTS, OH, Nitrite, metals, and lipid peroxidation. The present review presents pharmacological activities of different species of edible and medicinal mushrooms. This review provides tangible evidence that these mushrooms are an excellent source of natural constituents and antioxidants with potential application in pharmaceuticals and in treating and managing different diseases.

Mycopharmaceuticals and Nutraceuticals: Promising Agents to Improve Human Well-Being and Life Quality

Fungi, especially edible mushrooms, are considered as high-quality food with nutritive and functional values. They are of considerable interest and have been used in the synthesis of nutraceutical supplements due to their medicinal properties and economic significance. Specific fungal groups, including predominantly filamentous endophytic fungi from Ascomycete phylum and several Basidiomycetes, produce secondary metabolites (SMs) with bioactive properties that are involved in the antimicrobial and antioxidant activities. These beneficial fungi, while high in protein and important fat contents, are also a great source of several minerals and vitamins, in particular B vitamins that play important roles in carbohydrate and fat metabolism and the maintenance of the nervous system. This review article will summarize and discuss the abilities of fungi to produce antioxidant, anticancer, antiobesity, and antidiabetic molecules while also reviewing the evidence from the last decade on the importance of research in fungi related products with direct and indirect impact on human health.

Loose Ends in the Cortinarius Phylogeny: Five New Myxotelamonoid Species Indicate a High Diversity of These Ectomycorrhizal Fungi with South American Nothofagaceae

This paper is a contribution to the current knowledge of taxonomy, ecology and distribution of South American Cortinarius (Pers.) Gray. Cortinarius is among the most widely distributed and species-rich basidiomycete genera occurring with South American Nothofagaceae and species are found in many distinct habitats, including shrublands and forests. Due to their ectomycorrhizal role, Cortinarius species are critical for nutrient cycling in forests, especially at higher latitudes. Some species have also been reported as edible fungi with high nutritional quality. Our aim is to unravel the taxonomy of selected Cortinarius belonging to phlegmacioid and myxotelamonioid species based on morphological and molecular data. After widely sampling Cortinarius specimens in Patagonian Nothofagaceae forests and comparing them to reference collections (including holotypes), we propose five new species of Cortinarius in this work. Phylogenetic analyses of concatenated rDNA ITS-LSU and RPB1 sequences failed to place these new species into known Cortinarius sections or lineages. These findings highlight our knowledge gaps regarding the fungal diversity of South American Nothofagaceae forests. Due to the high diversity of endemic Patagonian taxa, it is clear that the South American Cortinarius diversity needs to be discovered and described in order to understand the evolutionary history of Cortinarius on a global scale.

Characterization of Phenolics in Rejected Kiwifruit and Their Antioxidant Potential

Kiwifruit hold significant nutritional value and are a good source of antioxidants due to their diverse range of bioactive compounds. Kiwifruit waste is generated throughout the food supply chain, particularly during transportation and storage. Kiwifruit rejected from the retail market due to unfavorable appearance still possess potential economic value as kiwifruit are abundant in phenolic compounds. The present work studied the phenolic profile and antioxidant potential of rejected kiwifruit, including SunGold (Actinidia chinensis), Hayward (Actinidia deliciosa), and round organic Hayward (Actinidia deliciosa). Regarding phenolics estimation, SunGold possessed the highest TPC (0.72 ± 0.01 mg GAE/g), while Hayward exhibited the highest TFC (0.05 ± 0.09 mg QE/g). In antioxidant assays, SunGold showed the highest antioxidant activities in DPPH (0.31 ± 0.35 mg AAE/g), FRAP (0.48 ± 0.04 mg AAE/g), ABTS (0.69 ± 0.07 mg AAE/g), •OH-RSA (0.07 ± 0.03 mg AAE/g) assays, and FICA (0.19 ± 0.07 mg EDTA/g), whereas Hayward showed the highest RPA (0.09 ± 0.02 mg AAE/g) and TAC (0.57 ± 0.04 mg AAE/g). Separation and characterization of phenolics were conducted using LC-ESI-QTOF-MS/MS. A total of 97 phenolics were tentatively characterized from rejected SunGold (71 phenolics), Hayward (55 phenolics), and round organic Hayward (9 phenolics). Hydroxycinnamic acids and flavonols were the most common phenolics characterized in the three samples. The quantitative analysis was conducted by HPLC-PDA and found that chlorogenic acid (23.98 ± 0.95 mg/g), catechin (23.24 ± 1.16 mg/g), and quercetin (24.59 ± 1.23 mg/g) were the most abundant phenolics present in the rejected kiwifruit samples. The notable presence of phenolic compounds and their corresponding antioxidant capacities indicate the potential value of rescuing rejected kiwifruit for further utilization and commercial exploitation.

Biological activity of aqueous extracts of Southern Brazilian mushrooms

This study aims to perform a bioactive analysis of five mushrooms collected in south of Brazil. The total phenol content of the extracts was equivalent to the antioxidant activity by ACAP assay. All extracts were able to inhibit the growth of Acinetobacter baumanni, and Auricularia auricula and Lactarius deliciosus extract showed the best antibacterial activity. In addition, no extract showed cytotoxic activity against VERO cells at the highest concentration evaluated (2500 µg/mL). Our results showed better antioxidant activity through the inhibition of the oxidation via peroxyl radical. It can be observed that all extracts were active against A. baumanni, and even moderately, all extracts could be inhibited of at least one of the bacteria used in the study. Added for these, the aqueous extracts showed no toxicity in VERO cells, highlighting the importance of research about the active compounds of mushrooms of the region.

Antimicrobial activity, chemical composition and cytotoxicity of Lentinus crinitus basidiocarp

Lentinus crinitus (L.) Fr. (Basidiomycota: Polyporales) is a wild mushroom with several biotechnological applications; however, there are few studies on its chemical composition and antimicrobial activity. Therefore, this study aims to evaluate the chemical composition, cytotoxicity, and antimicrobial activity of L. crinitus basidiocarp. For that, its nutritional value (AOAC procedures) and its composition in some hydrophilic and lipophilic compounds (chromatographic techniques) were assessed. Moreover, the potential hepatotoxic effects were evaluated using a primary cell culture obtained from porcine liver, and its growth inhibitory capacity was also evaluated against four human tumour cell lines (spectrophotometric assays). The antimicrobial activity was evaluated by microdilution against eight bacteria and fungi. The basidiocarp has a high content of carbohydrates and, therefore, a relatively high energetic value. It is also rich in soluble sugars, β-tocopherol, phenolic acids, mainly p-hydroxybenzoic acid, and organic acids, mainly malic acid. L. crinitus did not show cytotoxicity in non-tumour cells, but it did not inhibit the growth of human tumour cell lines either. The basidiocarp has a wide antimicrobial activity, inhibiting the growth of different species of bacteria and fungi. It showed minimum bactericidal and fungicidal concentration values similar to or lower than those verified by commercial antibiotics or food additives used as preservatives. The antimicrobial activity was more evident against Listeria monocytogenes, Salmonella enterica, and Penicillium ochrochloron, followed by Aspergillus ochraceus and Trichoderma viride, when compared to the controls. The results obtained in this study showed that L. crinitus basidiocarp has great potential to be used by the industry without toxicity risks.

Culinary–medicinal mushrooms: a review of organic compounds and bioelements with antioxidant activity

There are about 3000 species of mushrooms, which have a high amount of substances that are beneficial to human health, such as antioxidants. It is well known that oxidative stress plays an important role in the etiopathogenesis of many diseases, including cancer, cardiovascular disorders, and diseases of the central nervous system. One way to prevent homeostasis disorders that occur as a result of excessive production of pro-oxidative substances is to include the ingredients having antioxidant properties in the diet. Several compounds, such as those with phenolic and indole derivatives as well as carotenoids and some vitamins, exhibit antioxidant activity. These substances are present in many foods, including mushrooms. In addition, they have certain unique compounds that are not found in other sources (e.g., norbadione A). The present work discusses selected ingredients exhibiting antioxidant activity, which are found in various species of mushrooms as wells as describes the content of these compounds in the extracts obtained from mushrooms using artificial digestive juice.

Impact on Physicochemical Composition and Antioxidant Activity of the Wild Edible Mushroom Cyttaria espinosae Subjected to Drying

The wild edible mushroom 'digüeñe' (Cyttaria espinosae) is a mushroom with interesting flavor and nutritional properties, but highly perishable with a consumption very limited, generating inevitable economic losses for their producers. Because of that, the aim of this study was the evaluation of two drying methods (hot-air drying and freeze-drying) in its bioactive and physicochemical composition for its preservation. The best performances of antioxidant capacity were 62 μmol TE g^-1 (ORAC) and 14.21 μmol TE g^-1 (DPPH), being higher compared with other vegetable sources. Its protein (5.33 %), fiber (5.58 %) and K (2.82 mg g^-1 ) content also stands out. β-Carotene retention was 35.02 and 23.25 % after freeze drying and hot-air, respectively. Freeze-drying seems a good strategy for digüeñe, bioactive compounds, color and structure were better maintained. This work represents the first characterization of dehydrated digüeñe, constituting approaches for its valorization and use in the food industry.

Traditional mycological knowledge and processes of change in Mapuche communities from Patagonia, Argentina: A study on wild edible fungi in Nothofagaceae forests

Practices, perceptions, beliefs, and other forms of relationships between rural inhabitants and fungi have scarcely been studied in Patagonia. In this work, we analyze species richness, cultural importance, and modes of use of wild edible fungi in five Mapuche communities in northwest Patagonia of Argentina. Through an ethnobiological approach, we carried out semistructured interviews, walks in forests, and participant observations. Data were analyzed qualitative and quantitatively. Community members collected 17 species in environments with different degrees of human disturbance that they consumed fresh in situ, after some processing or stored for later consumption or trade. Indigenous morels such as Morchella aff. tridentina, M. aff. septimelata, and an unidentified species of Morchella had the greatest cultural importance at the regional level, followed by the exotic Suillus luteus and the native Cyttaria hariotti. Most of these species were frequently mentioned as having commercial value, continuity of use over time, and outstanding organoleptic properties. The remaining species currently have occasional use. The differential use of edible fungi, practices, transferences, and resignifications, as well as new technologies for storage, were analyzed. Regional knowledge about fungi reflects important features of Mapuche tradition but also the process of change in responding to complex and dynamic socioeconomic and ecological contexts.

Chemical Composition, Antioxidant and Antihyperglycemic Activities of the Wild Lactarius deliciosus from China

The wild mushroom Lactarius deliciosus from China was studied for the first time to obtain information about its chemical composition, antioxidant, and antihyperglycemic activities. Nutritional value, dietary fiber, fatty acids, metal elements, free sugars, free amino acids, organic acids, flavor 5′-nucleotides, and volatile aroma compounds were determined. Potential antioxidant and antihyperglycemic activities were also tested by investigating 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals scavenging activities, ferric ion reducing activity, as well as α-amylase and α-glucosidase inhibitory activities using ethanol and aqueous extracts. The results showed that L. deliciosus was a good wild mushroom with high protein, carbohydrate, and dietary fiber contents, while low in fat and calorie, extensive unsaturated fatty acids contents, with negligible health risks about harmful metal elements. Twenty kinds of free amino acids were detected with a total content 3389.45 mg per 100 g dw. Flavor 5′-nucleotides including 5′-CMP, 5′-UMP, 5′-IMP, and 5′-AMP were 929.85, 45.21, 311.75, and 14.49 mg per 100 g dw, respectively. Mannitol (7825.00 mg per 100 g dw) was the main free sugar, and quininic acid (729.84 mg per 100 g dw) was the main organic acid. Twenty-five kinds of volatile aroma compounds were identified, acids (84.23%) were the most abundant compounds based on content, while aldehydes (15 of 25) were the most abundant compounds based on variety. In addition, both ethanol and aqueous extracts from L. deliciosus exhibited excellent antioxidant activity. While in antihyperglycemic activity tests, only ethanol extracts showed inhibitory effects on α-amylase and α-glucosidase.

A Natural Benzofuran from the Patagonic Aleurodiscus vitellinus Fungus has Potent Neuroprotective Properties on a Cellular Model of Amyloid-β Peptide Toxicity

Alzheimer's disease (AD) is characterized by amyloid plaques that form due to an increase in amyloid-β peptide (Aβ) aggregation. One strategy in the search of new treatments for AD focuses on compounds that decrease Aβ accumulation. Compounds containing a benzofuran ring have been described to play an important role in decreasing Aβ-induced toxicity; however, only synthetic benzofurans have been tested thus far. The aim of the present study was to examine the in vitro neuroprotective properties of fomannoxin (Fx), a natural benzofuran isolated from cultures of the Andean-Patagonian fungi Aleurodiscus vitellinus, and evaluate its effect on Aβ peptide. We tested the effect of Fx at a wide concentration range (10-11-10-4 M) in PC-12 cells, and found the compound did not alter cellular viability. Fx also showed a concentration-dependent effect on the Aβ-induced toxicity in PC12 cells, showing viability above 100% at 10-6 M. We then measured the effect of Fx (10-7-10-5 M) on the frequency of cytosolic Ca2+ transients in rat hippocampal neurons at both acute and chronic (24 h) times. Acute incubation with Fx increased the frequency of cytosolic Ca2+ transients to values around 200%, whereas chronic incubation with Fx increased the frequency of Ca2+ transients. Finally, the Aβ-induced decrease in intracellular Ca2+ transients was prevented when Fx (10-6 M) was co-incubated with Aβ (5×10-6 M). The results suggest a potent neuroprotective effect of this naturally occurring benzofuran against Aβ peptide toxicity that could be mediated by an interference with it binding to plasma membrane, and lead Fx as new chemical entity to develop pharmacological tools against Aβ peptide neurotoxicity.

The enigmatic Cortinarius magellanicus complex occurring in Nothofagaceae forests of the Southern Hemisphere

Cortinarius magellanicus Speg. is an edible, ectomycorrhizal fungus, widely distributed in Argentina, Chile and New Zealand. However, earlier studies already indicated that the epithet 'magellanicus' might have been applied in a wide sense, thus circumscribing several species. A neotype was designated by Moser and Horak (1975) due Spegazzini's type was lost. Argentinian Nothofagaceae forests' samples, from autumn of 2017, morphologically recognized as C. magellanicus were used for a phylogenetic analysis, including sequences from type material and closely related species. Our results showed that C. magellanicus represents a complex of species, with at least three phylogenetic lineages, each with strong regionalism and distinct host associations. Cortinarius magellanicus s. str. is restricted to Patagonia of Argentina and Chile. The misidentified reports from New Zealand and Australia represent distinct and different lineages. In the present contribution, the re-description of C. magellanicus is based on neotype material and two new species are proposed. Cortinarius vitreopileatus var. similissimus is described as variety from New Zealand resembling C. magellanicus, however without close phylogenetic relationship to it. The taxonomic delimitation for C. magellanicus species complex is of high relevance due to the abundance of these fungi and their ectomycorrhizal role in Nothofagaceae forests in Gondwanian region.

Genetic diversity of Lepista nuda (Agaricales, Basidiomycota) in Northeast China as indicated by SRAP and ISSR markers

Lepista nuda is a popular wild edible mushroom that grows in China. In this study, we used ISSR and SRAP molecular markers to analyze the genetic diversity of 72 samples of L. nuda from eight populations in Northeast China. In total, six ISSR primers and five pairs of SRAP primers that produced clear and polymorphic banding profiles were selected for assessing L. nuda genetic diversity. The results revealed a high level of genetic variation among the 72 samples (94.4% polymorphism) but a low degree of gene flow among the populations. Among L. nuda populations, genetic distance was not correlated significantly with geographic distance. The antioxidant activity of the samples from each population was also tested and the result showed that all the selected samples had more than 60% DPPH scavenging activities. Nonetheless, the antioxidant activity diversity is not coincident with both the genetic diversity and the geographic distribution. The results indicate that ISSR and SRAP molecular markers are useful for studying the genetic diversity of L. nuda. The results also suggest that L. nuda populations in Northeast China require protection.

Chemical composition and bioactive properties of the wild mushroom Polyporus squamosus (Huds.) Fr: a study with samples from Romania

In Eastern Europe, wild mushrooms are widely collected in mountain areas and used for their medicinal properties or as healthy foods. This study aimed at determining the chemical composition (nutritional value, free sugars, organic acids, phenolic compounds, fatty acids and tocopherols) and bioactive properties (antioxidant, antimicrobial and antiquorum sensing) of wild Polyporus squamosus (Huds.) Fr from Romania. The results indicate that the fruiting bodies of P. squamosus are rich in carbohydrates (74.22 g per 100 g dw) and proteins (18.7 g per 100 g dw). Trehalose was the main free sugar, while malic acid was the organic acid detected in the highest amount (2.21 g per 100 g dw), and p-hydroxybenzoic acid was the main phenolic compound. Among tocopherols, β-tocopherol was the most abundant form (114.7 μg per 100 g dw). Additionally, regarding the fatty acids' pattern, polyunsaturated acids represent more than 57% of all fatty acids, followed by monounsaturated fatty acids (24.96%). The highest measured antioxidant effect of P. squamosus extract was found using the TBARS inhibition assay (EC₅₀ = 0.22 mg mL^-1), followed by the β-carotene/linoleate assay (EC₅₀ = 1.41 mg mL^-1). A minimal inhibitory concentration of the tested extracts was obtained between 0.61-20.4 mg mL^-1, while the bactericidal effect was achieved between 1.2-40.8 mg mL^-1. Antibiofilm potential was obtained at all tested concentrations, and subinhibitory concentrations of the extract exhibited an antiquorum effect and reduced the formation of P. aeruginosa pili, which all together influenced the virulence of this bacterium. Due to the investigated bioactivities and compounds of P. squamosus and its well-balanced nutritional profile, this mushroom can be further used as a medicinal ingredient based on its antioxidative and antimicrobial potential.

Gene cloning, expression, and characterization of trehalose-6-phosphate synthase from Pleurotus ostreatus

Trehalose-6-phosphate synthase (TPS; EC2.4.1.15) catalyzes the first step in trehalose synthesis, which involves transfer of glucose from uridine diphosphate glucose (UDPG) to glucose 6-phosphate (G6P) to form trehalose-6-phosphate. To determine the gene and enzymatic characteristics of TPS in Pleurotus ostreatus, we cloned and sequenced the cDNA of PoTPS1, which contains a 1665 bp open reading frame that encodes a 554-amino acid protein with a predicted molecular weight of 62.01 kDa. This gene was expressed in Escherichia coli BL21 and then the recombinant protein was purified and characterized. Results showed that the optimum pH and temperature for the recombinant PoTPS1 were 7.4 and 30 °C, respectively; the K_m value against G6P and UDPG were 0.14 and 0.17 mM, respectively, and the V_max and K_cat values were 91.86 nkat/g and 5.89 s^-1 , respectively. Trehalose content was as high as 158.88 mg g^-1 dry weight after heat treatment at 40 °C for 15 h, which was consistent with highest TPS1 activity at that time point. This result indicated that PoTPS1 was responsible for trehalose synthesis in P. ostreatus.