Influence of Storage Methods on the Vitality and Growth Rate of Macrofungi

The work contains a comparative analysis of methods for storing pure cultures of macrofungi. The study used 20 species of macrofungi from various taxonomic and ecological-trophic groups. Storage was carried out using five methods: serial subculturing, storage under a layer of distilled water and three cryopreservation protocols: a protocol using blocks of agar medium, a "perlite protocol," and a "grain protocol." For the selected cryostorage methods, various cryoprotective compounds (glycerol, trehalose) were used. Radial growth rate was used as a criterion for the state of crops. The values of the radial growth rate obtained immediately after isolation of the pure culture were chosen as the control. It has been shown that the most favorable for preserving the physiological activity of cultures are the storage method under a layer of distilled water, "perlite" and "grain" cryopreservation protocols.

Cultivation of a Wild Strain of Wood Ear Auricularia cornea from Brazil

Auricularia cornea has become one of the most important cultivated mushrooms worldwide. Although not remarkably flavorful, Auricularia species are very versatile and rehydrate easily after drying, adding a unique and pleasing texture to the dishes. In this study, we collected, identified, and domesticated a wild strain of A. cornea from the Brazilian Atlantic Rainforest. The wild strain was evaluated for mycelial growth at different temperatures and substrates, biological efficiency, and nutritional composition. The temperature that best favored the A. cornea mycelium growth was 30 °C, and the substrate was sterile Eucalyptus sawdust. The highest biological efficiency value obtained was 106.90 ± 13.28%. Nutritional analysis showed that the produced wood ears contained 71.02% carbohydrates, 19.63% crude fiber, 11.59% crude protein, 10.19% crude fat, and 4.24% ash on dry matter basis. For the mineral content profile, the elements K and P were the most abundant. This is the first report on cultivation of a wild strain of A. cornea from Brazil.

Properties of Yogurts Enriched with Crude Polysaccharides Extracted from Pleurotus ostreatus Cultivated Mushroom

Increasingly, consumers are looking for products with specific nutritional and health-promoting properties. The answer of the producers for this demand is fortified food. The raw material that can be used to enrich food is, among others, mushrooms. Crude water soluble polysaccharides (cWSP) were isolated from fruiting bodies of Pleurotus ostreatus (oyster) mushroom. Chemical analysis showed that they consisted mainly of carbohydrates (~61%), protein (~9%) and phenolics (~0.8%). The isolated cWSP were used to obtain enriched cow milk set yogurts. cWSP were added at the concentration of 0.1%, 0.2%, 0.3%, 0.4% and 0.5%, and milk containing no cWSP was prepared as the control. All of the variants were fermented via applying two commercially available culture starters. The addition of cWSP led to a drop in pH in the case of one starter culture. Also, the decline in total soluble solids (TSS) content was higher where cWSP was used for the enrichment. Texture profile analysis (TPA) revealed that parameters of hardness and gumminess increased along with the concentration of cWSP (reaching values approximately 7-8 times higher, compared to the control). A significant increase in syneresis level (proportional to cWSP concentration and ranging from ~10% to ~50%) was also observed after the fermentation. Fortifying milk with cWSP led to a slight increase in antioxidant capacity in FRAP assay (up to ~12%) and ABTS assay (up to ~23%). The results demonstrate that using cWSP to enrich set-type yogurts is fairly limited.

Substrate level optimization for better yield of oyster mushroom (Pleurotus ostreatus) production, using different ratio of rice straw and sugarcane bagasse

Mushroom cultivation has been identified as a cost-effective technique for converting lignocellulosic wastes. This study utilized a combination of two distinct agro-wastes as a substrate for better Pleurotus ostreatus cultivation. Oyster mushroom has been cultivated on substrates made up of rice straw and sugarcane bagasse with different ratios. This technique gives a significant difference between mycelium running, fruit body formation, yield, biological efficiency, and better-quality taste of Pleurotus ostreatus mushroom. A minimum of 19 days were required for 1st harvesting from bag number T4 where substrate ratio was used at 3:2. The maximum yield was found as T4 (886 g/kg) in bag number on the dry substrate from the first flushing. According to proximate analyses, protein contents were increased in treatment bags compared with the control. Anyhow, the enrichment of L-glutamine content in the fruit body was found at 11.8 mg/g from 1st flushing in T4 bag, among the other bags and the flavour was changed due to the substrate level composition. According to the study, 3:2 is an ideal substrate ratio for the development of oyster mushrooms cultivation. According to this ratio, it helps the farmer for minimum time to grow the mushroom fruit body and reduce the lignocellulosic waste materials from the environmental pollution along with increasing the flavour in the fruitbody compared with commonly produced mushroom substrate (T6). Therefore, more research should be conducted to assess the consequences of combining different substrates and decreasing the lignocellulosic biomass by converting a protein-rich edible product through the oyster mushroom.

A narrative action on the battle against hunger using mushroom, peanut, and soybean-based wastes

Numerous generations have been affected by hunger, which still affects hundreds of millions of people worldwide. The hunger crisis is worsening although many efforts have been made to minimize it. Besides that, food waste is one of the critical problems faced by most countries worldwide. It has disrupted the food chain system due to inefficient waste management, while negatively impacting the environment. The majority of the waste is from the food production process, resulting in a net zero production for food manufacturers while also harnessing its potential. Most food production wastes are high in nutritional and functional values, yet most of them end up as low-cost animal feed and plant fertilizers. This review identified key emerging wastes from the production line of mushroom, peanut, and soybean (MPS). These wastes (MPS) provide a new source for food conversion due to their high nutritional content, which contributes to a circular economy in the post-pandemic era and ensures food security. In order to achieve carbon neutrality and effective waste management for the production of alternative foods, biotechnological processes such as digestive, fermentative, and enzymatic conversions are essential. The article provides a narrative action on the critical potential application and challenges of MPS as future foods in the battle against hunger.

The Mushroom Glucans: Molecules of High Biological and Medicinal Importance

Carbohydrates, including polysaccharide macromolecules, are the main constituents of the fungal cell wall. Among these, the homo- or heteropolymeric glucan molecules are decisive, as they not only protect fungal cells but also have broad, positive biological effects on the animal and human bodies. In addition to the beneficial nutritional properties of mushrooms (mineral elements, favorable proteins, low fat and energy content, pleasant aroma, and flavor), they have a high glucan content. Folk medicine (especially in the Far East) used medicinal mushrooms based on previous experience. At the end of the 19th century, but mainly since the middle of the 20th century, progressively more scientific information has been published. Glucans from mushrooms are polysaccharides that contain sugar chains, sometimes of only one kind (glucose), sometimes having several monosaccharide units, and they have two (α and β) anomeric forms (isomers). Their molecular weights range from 104 to 105 Da, and rarely 106 Da. X-ray diffraction studies were the first to determine the triple helix configuration of some glucans. It seems that the existence and integrity of the triple helix structure are criteria for their biological effects. Different glucans can be isolated from different mushroom species, and several glucan fractions can be obtained. The biosynthesis of glucans takes place in the cytoplasm, the processes of initiation and then chain extension take place with the help of the glucan synthase enzyme complex (EC 2.4.1.34), and the sugar units are provided by sugar donor UDPG molecules. The two methods used today for glucan determination are the enzymatic and Congo red methods. True comparisons can only be made using the same method. Congo red dye reacts with the tertiary triple helix structure, and the resulting glucan content better reflects the biological value of glucan molecules. The biological effect of β-glucan molecules is proportional to the integrity of the tertiary structure. The glucan contents of the stipe exceed the values of the caps. The glucan levels of individual fungal taxa (including varieties) differ quantitatively and qualitatively. This review presents in more detail the glucans of lentinan (from Lentinula edodes), pleuran (from Pleurotus ostreatus), grifolan (from Grifola frondose), schizophyllan (from Schizophyllum commune), and krestin (from Trametes versicolor), along with their main biological effects.

Wild Mushrooms as a Source of Protein: A Case Study from Central Europe, Especially the Czech Republic

Wild mushroom foraging has a long tradition, especially in the region of Central Europe. Wild mushrooms are a valuable food resource, as they provide nutritional benefits to the European population. They offer a relatively high content of protein and are traditionally used in many European cuisines as a substitute for meat. This is particularly true in times of crisis, such as wars and pandemics. The study presented in this paper shows that wild mushrooms can substitute around 0.2 percent of daily protein intake and contribute around 3% to the agricultural output of the Czech economy, which was selected as a representative for Central Europe. The calculated real price of wild mushrooms indicates their increasing popularity as a source of food protein in Central Europe, while their price seems to be independent of the quantity supplied.

Comparative Analysis of the Metabolites and Biological Activity of Cultivated and Wild Lignosus rhinocerotis

In this paper, Lignosus rhinocerotis (Cooke) Ryvarden (L. rhinocerotis) cultivated in rice medium (LRR) and in sawdust medium (LRS) was harvested. Then, in terms of the LRR, LRS, and wild L. rhinocerotis (LRW), the total flavonoid contents, total polyphenol contents, total polysaccharide contents, and metabolites were detected; antioxidants of their aqueous extracts and anti-inflammatory of their polysaccharides were performed. In addition, the possible mechanism of the polysaccharides of L. rhinocerotis inhibiting lung damage was elucidated. The results showed that 32 compounds were characterized in L. rhinocerotis, including flavonoids, terpenoids, lignans, and steroids and there were 20 compounds in cultivated and wild L. rhinocerotis; LRR has the highest total polyphenol and flavonoid contents, as well as ABTS and DPPH scavenging capacity. The total polysaccharide contents and the FRAP scavenging capacity of wild L. rhinocerotis were higher than those of cultivated L. rhinocerotis. The inhibition of polysaccharides of LRW (PLRW) on LPS-induced MRC-5 damage was stronger than that of the polysaccharides from cultivated L. rhinocerotis. The PLRW may alleviate lung damage by inhibiting the NLRP3 pathway and thereby suppressing the inflammatory response. In summary, both cultivated and wild L. rhinocerotis are abundant in bioactive components and have antioxidant and anti-inflammatory activities.

Challenges and opportunities in producing high-quality edible mushrooms from lignocellulosic biomass in a small scale

Mushrooms are high-value products that can be produced from lignocellulosic biomass. Mushrooms are the fruiting body of fungi and are domestically cultivated using lignocellulosic biomass obtained from agricultural byproducts and woody biomass. A handful of edible mushroom species are commercially cultivated at small, medium, and large scales for culinary and medicinal use. Details about different lignocellulosic biomass and their composition that are commonly used to produce mushrooms are outlined in this review. In addition, discussions on four major processing steps (i) producing solid and liquid spawn, (ii) conventional and mechanized processing lignocellulosic biomass substrates to produce mushroom beds, (iii) maintaining growth conditions in climate-controlled rooms, and (iv) energy requirements and managements to produce mushrooms are also provided. The new processing methods and technology outlined in this review may allow mushrooms to be economically and sustainably produced at a small scale to satisfy the growing food needs and create rural jobs. KEY POINTS: • Some of the challenges faced by small-scale mushroom growers are presented. This review is expected to stimulate more research to address the challenges.

γ-Glutamyl-β-phenylethylamine, a novel α-glucosidase and α-amylase inhibitory compound from Termitomyces robustus, an edible Nigerian mushroom

Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary and nutraceutical properties. Methanol extract from fruiting bodies of Termitomyces robustus was evaluated for antidiabetic activity using in vitro α-amylase and α-glucosidase assays. The isolation and structural elucidation of metabolites from the T. robustus extract afforded five compounds including a new natural product γ-glutamyl-β-phenylethylamine 3 and four known phenyl derivatives: tryptophan 1, 4-hydroxyphenylacetic acid 2, 4-hydroxyphenylpropionic acid 4, and phenyllactic acid 5. Structures were elucidated from analyses of spectroscopic data (1 D and 2 D NMR, HRESIMS) and all isolated compounds were tested for α-amylase and α-glycosidase inhibitory activity. The in vitro assay established crude extract to possess α- amylase and α-glucosidase inhibition with IC₅₀ of 78.05 µg/mL and 86.10 µg/mL, respectively. The isolated compounds compared favourably with the standard drug, acarbose with IC₅₀ ranging from 6.18-15.08 µg/mL and 18.28-44.63 µg/mL for α-amylase and glucosidase, respectively.

HPLC-DAD characterization of phenolic profile and in vitro antioxidant, anticholinesterase, and antidiabetic activities of five mushroom species from Turkey

In this study, Daedalea quercina (L.) Pers., Hydnum repandum L., Inonotus radiatus (Sowerby) P. Karst., Omphalotus olearius (DC.) Singer, and Schizophyllum commune Fr. hexane and methanol extracts were subjected to the spectrophotometric assays for antioxidant and enzyme inhibitory activities, which are linked with human diseases that are very prevalent in recent years. Additionally, phenolic compounds of the mushrooms were quantified by HPLC-DAD. The best antioxidant activity was found in H. repandum methanol extract (IC₅₀: 12.04 ± 0.24 µg/mL) in the β-carotene-linoleic assay; I. radiatus methanol extract in DPPH^• (81.22 ± 0.50%), ABTS^•+ (IC₅₀: 73.47 ± 0.18 µg/mL), and CUPRAC (A_0.50: 88.21 ± 0.02 µg/mL) assays; S. commune hexane extract (53.36 ± 0.89%) in the metal chelating assay. O. olearius hexane extract was found as the best inhibitor against AChE (71.58 ± 0.28%) and BChE (67.30 ± 0.15%). When I. radiatus methanol (95.88 ± 0.74%) and H. repandum hexane (95.75 ± 0.16%) extracts showed close α-amylase inhibitory activity to acarbose (96.68 ± 0.08%), D. quercina methanol extract (70.79 ± 0.34%) had higher α-glucosidase inhibitory activity than acarbose (67.01 ± 2.28%). Among 16 phenolic compounds analyzed, gallic acid (0.02 ± 0.01-0.23 ± 0.01 µg/g) was detected in all studied mushrooms. This study provides that investigated mushrooms can be used for further research, which can lead to the development of new natural remedies to alleviate complications related to oxidative stress, diabetes, and neurological diseases.

Health benefits of edible mushroom polysaccharides and associated gut microbiota regulation

Edible mushrooms have been an important part of the human diet for thousands of years, and over 100 varieties have been cultivated for their potential human health benefits. In recent years, edible mushroom polysaccharides (EMPs) have been studied for their activities against obesity, inflammatory bowel disease (IBD), and cancer. Particularly, accumulating evidence on the exact causality between these health risks and specific gut microbiota species has been revealed and characterized, and most of the beneficial health effects of EMPs have been associated with its reversal impacts on gut microbiota dysbiosis. This demonstrates the key role of EMPs in decreasing health risks through gut microbiota modulation effects. This review article compiles and summarizes the latest studies that focus on the health benefits and underlying functional mechanisms of gut microbiota regulation via EMPs. We conclude that EMPs can be considered a dietary source for the improvement and prevention of several health risks, and this review provides the theoretical basis and technical guidance for the development of novel functional foods with the utilization of edible mushrooms.

Application of Near-Infrared Spectroscopy to Investigate Some Endogenic Properties of Pleurotus ostreatus Cultivars

Fourteen different Pleurotus ostreatus cultivars (Po_1–Po_14) were tested for free amino acid content (fAA), total polyphenol content (TPC), and antioxidant capacity (Ferric Reducing Ability of Plasma—FRAP) to select the cultivars with the most favorable traits. Automatic amino acid analyzer (fAA) and spectrophotometric assay (TPC, FRAP) results as well as Fourier-transform near infrared (FT-NIR) spectra were evaluated with different chemometric methods (Kruskal–Wallis test, Principal Component Analysis—PCA, Linear Discriminant Analysis—LDA). Based on total free amino acid concentrations and FRAP values, the Po_2 cultivar was found to be the most favorable. Types Po_3, Po_8, Po_10 and Po_12 were separated using PCA. Based on the spectral profile, they may contain polyphenols and reducing compounds of different qualities. LDA classification that was based on the concentrations of all free amino acids, cysteine, and proline of the cultivars was performed with an accuracy of over 90%. LDA classification that was based on the TPC and FRAP values was performed with an accuracy of over 83%.