Development of nutraceutical formulations based on the mycelium of Pleurotus ostreatus and Agaricus bisporus

Fungi as biotechnological allies: Exploring contributions of edible and medicinal mushrooms

Edible and medicinal mushrooms possess excellent nutritional properties due to their incredible versatility in growing on different substrates and producing extracellular enzymes with a wide range of specificity. These features make them excellent candidates for various biotechnological applications. In this context, biotechnological applications using edible and medicinal mushrooms can focus on the bioprocessing of agro-industrial wastes, an economical and environmentally friendly strategy. This review, based on recent original research and scientific reviews, highlights the versatility and potential of mushrooms in terms of sustainability and efficiency. We emphasized the biotechnological applications of edible and medicinal mushrooms and their enzymes including food production with high nutraceutical value by enhancing the quality and flavor of food industry products. Other biotechnological applications addressed in this review were cosmeceutical and biomedical development using mushroom extracts with bioactive compounds; wood pulp pretreatment processes in the pulp and paper industry; bioethanol production; and bioremediation for decontaminating soils and polluted effluents. These applications explain how edible and medicinal mushrooms have gained significance in biotechnology over the years, opening new avenues for innovation. The current tendency to study edible and medicinal mushrooms has gained the attention of researchers because these are still less known organisms becoming an attractive and natural source of novel bioactive compounds that could be integrated into a circular model production.

Mycelium vs. Fruiting Bodies of Edible Fungi-A Comparison of Metabolites

Edible mushrooms are widely appreciated for their appealing flavours, low caloric values and high content of presumably health-protecting metabolites. Their long history of safe use together with the looming worldwide food crisis have revived the idea of generating meat analogues and protein isolates by the controlled fermentation of mycelia of these edible fungi as a dietary option. The occurrence of proteins, polysaccharides, smaller metabolites, metal ions and toxins in mycelia and fruiting bodies is compared among the three most popular species, Agaricus bisporus (button mushroom), Pleurotus ostreatus (oyster mushroom), Lentinus edodes (shiitake) and some closely related species. Large effects of substrate chemistry, strain, developmental stage and ecological interactions result in a wide variation of the concentrations of some metabolites in both mycelial cells and fruiting bodies. This is obviously a result of the high adaptation abilities required to survive in natural habitats. Fungal bioprocesses are decoupled from agricultural production and can be operated anytime, anywhere, and on any scale according to demand. It is concluded that fungal biomass, if produced under food-grade conditions and on an industrial scale, could provide a safe and nutritious meat substitute and protein isolates with a high biological value for future vegan foods.

Development of a consortium-based microbial agent beneficial to composting of distilled grain waste for Pleurotus ostreatus cultivation

BACKGROUND

Pleurotus ostreatus is an edible mushroom popularly cultivated worldwide. Distilled grain waste (DGW) is a potential substrate for P. ostreatus cultivation. However, components in DGW restrict P. ostreatus mycelial growth. Therefore, a cost-effective approach to facilitate rapid P. ostreatus colonization on DGW substrate will benefit P. ostreatus cultivation and DGW recycling.

RESULTS

Five dominant indigenous bacteria, Sphingobacterium sp. X1, Ureibacillus sp. X2, Pseudoxanthomonas sp. X3, Geobacillus sp. X4, and Aeribacillus sp. X5, were isolated from DGW and selected to develop a consortium-based microbial agent to compost DGW for P. ostreatus cultivation. Microbial agent inoculation led to faster carbohydrate metabolism, a higher temperature (73.2 vs. 71.2 °C), a longer thermophilic phase (5 vs. 3 days), and significant dynamic changes in microbial community composition and diversity in composts than those of the controls. Metagenomic analysis showed the enhanced microbial metabolisms, such as xenobiotic biodegradation and metabolism and terpenoid and polyketide metabolism, during the mesophilic phase after microbial agent inoculation, which may facilitate the fungal colonization on the substrate. In accordance with the bioinformatic analysis, a faster colonization of P. ostreatus was observed in the composts with microbial inoculation than in control after composting for 48 h, as indicated from substantially higher fungal ergosterol content, faster lignocellulose degradation, and higher lignocellulase activities in the former than in the latter. The final mushroom yield shared no significant difference between composts with microbial inoculation and control, with 0.67 ± 0.05 and 0.60 ± 0.04 kg fresh mushroom/kg DGW, respectively (p > 0.05).

CONCLUSION

The consortium-based microbial agent comprised indigenous microorganisms showing application potential in composting DGW for providing substrate for P. ostreatus cultivation and will provide an alternative to facilitate DGW recycling.

M. B. Morais A, Freitas AC, C. F. R. Ferreira I, Pintado M. Valorization of Mushroom By-Products as a Source of Value-Added Compounds and Potential Applications

Nowadays, the food sector is highly concerned with environmental issues and foreseen to develop strategies to reduce waste and losses resulting from activities developed in the food system. An approach is to increment added value to the agro-industrial wastes, which might provide economic growth and environmental protection, contributing to a circular economy. Mushroom by-products represent a disposal problem, but they are also promising sources of important compounds, which may be used due to their functional and nutritional properties. Research has been developed in different fields to obtain value added solutions for the by-products generated during mushroom production and processing. Bioactive compounds have been obtained and applied in the development of nutraceutical and pharmaceutical formulations. Additionally, other applications have been explored and include animal feed, fertilizer, bioremediation, energy production, bio-based materials, cosmetics and cosmeceuticals. The main purpose of this review is to highlight the relevant composition of mushroom by-products and discuss their potential as a source of functional compounds and other applications. Future research needs to explore pilot and industrial scale extraction methods to understand the technological feasibility and the economic sustainability of the bioactive compounds extraction and valorization towards different applications.

Selected edible medicinal mushrooms from Pleurotus genus as an answer for human civilization diseases

Edible mushrooms are classified as a functional food. The study aimed to initiate in vitro cultures of selected species of Pleurotus: P. citrinopileatus, P. djamor, P. eryngii, P. florida, P. ostreatus, and P. pulmonarius and to optimize the method of cultivation of these species to obtain raw materials characterized by pro-health properties. Another objective was to analyze the biologically active substances in the obtained mushroom materials. By determining the organic compounds and bioelements present in the species selected for the study, it was found that the fruiting bodies obtained by cultivation were characterized by a high content of phenolic and indole compounds. Similarly, the mycelia obtained from in vitro culture were found to contain significant amounts of organic compounds exhibiting biological effects such as lovastatin. The study revealed that the composition of biologically active substances varied between the mycelia obtained from in vitro cultures and the fruiting bodies obtained by cultivation.

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

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

Optimization of ergosterol extraction from Pleurotus mushrooms using response surface methodology

In this study, heat-assisted extraction (HAE) was used to optimise the extraction of ergosterol from Pleurotus ostreatus (PO) and Pleurotus eryngii (PE) using response surface methodology (RSM).

In Vitro Ecological Response of the Human Gut Microbiome to Bioactive Extracts from Edible Wild Mushrooms

This study presents the effect of two new products based on atomized extracts from edible wild mushrooms (RoBioMush1, RoBioMush2) on the microbiota of three target groups: clinically healthy (NG) individuals, individuals with nutritional disorders (ND), and individuals with cardiovascular diseases (CVD). The microbiota fingerprints were determined by quantitative polymerase chain reaction (qPCR). Modulations in the simulated microbiome were established and correlated with the presence of phenolic compounds released in the in vitro environment (a three-stage culture system GIS2 simulator, www.gissystems.ro). The high metabolizing capacity of NG and CVD correlated positively with the rest of the biological activities expressed in vitro. ND microbiota consumed a wide spectrum of monosaccharides from the products. Xylose was present in large quantities in the descending segment (minimum: 175 μg/mL for ND). The primary conclusion was that the microbiological ecosystem was modulated, as proven by the presence of specific biomarkers (e.g., ammonium levels and fingerprints of short-chain fatty acids–SCFAs), which stimulate the organism’s health status and were correlated with the restoration of a normal microbiota fingerprint.

Circular reuse of bio-resources: the role of Pleurotus spp. in the development of functional foods

The basidiomycetes fungi belonging to the genus Pleurotus could make an important contribution to sustainable functional food design because they possess an elevated protein content with a valuable essential amino acid scoring pattern, a unique dietary fibre profile, mainly comprised of branched β-glucan, high levels of some vitamins of the B group, vitamin D, Fe, Zn, Cu, Se and some bioactive mycochemicals, while the Na and fat contents are low. Moreover, Pleurotus spp. can grow efficiently on various clean by-products of food processing, such as wheat straw, wheat stalk and spent beer grain, thus representing a sustainable food source. This review illustrates the compositional variability of Pleurotus spp. grown on various by-products, in order to clarify its potential ability to address the needs of populations with endemic nutritional deficiencies as well as those populations at risk or affected by some chronic diseases. The perspectives for Pleurotus applications in functional foods decisively depend on consumers' acceptability. Hence, the sensory properties of Pleurotus spp. are also clarified herein. Lastly, the three main strategies of functional food development using Pleurotus spp. are summarized, namely its use as a fortifying agent, high-cost protein replacer and prebiotic ingredient.