Pleurotus nebrodensis (PN) is a large rare edible mushroom native to Xinjiang, China, and was only successfully domesticated and cultivated by humans in the early 1980s. Recently, this rare mushroom has begun to attract the attention of researchers. Some studies have found that the polysaccharides in the fruiting bodies of PN have biological activities such as immune regulation, antitumor effects, myocardial protection and liver protection, making it a source of high-quality functional health products.
Recent research into the high-yield liquid culture of PN mycelium offers an innovative pathway for producing functional polysaccharides that combat physical fatigue and oxidative stress. By optimizing growth conditions, this study achieved significant gains in both mycelium biomass (58.08% increase) and polysaccharide content (2.22% increase), positioning PN mycelium as a promising, cost-effective resource for developing anti-fatigue health products.
Image courtesy: Mushbank
Fatigue and the Demand for Functional Foods
Fatigue, whether due to physical or psychological stress, affects human health, workplace productivity, and overall quality of life. As populations increasingly seek natural, safe supplements to alleviate these symptoms, mushroom polysaccharides have shown promising anti-fatigue potential. Studies on edible mushroom polysaccharides underscore their benefits in enhancing immune response and protecting organs such as the heart and liver. However, the high cost and long growth cycles of traditional PN fruiting bodies make them challenging to scale for public consumption.
Unlike PN’s slow-growing fruiting bodies, mycelium—the vegetative structure that precedes fruiting—shares the same polysaccharide profile but has a much shorter cultivation period. By leveraging liquid culture systems, researchers can now control growth factors that directly enhance polysaccharide yield and bioactivity, making PN mycelium an ideal alternative for cost-effective, functional product development.
Enhanced Yield and Functional Benefits
Through a structured series of orthogonal experiments, researchers optimized liquid culture conditions to maximize both mycelium biomass and active ingredient concentration:
Increased Mycelium Yield and Polysaccharide Content: The optimized culture conditions led to a 58.08% increase in biomass and a 2.22% increase in polysaccharide content. This efficient cultivation approach significantly lowers production costs, especially compared to the high resource requirements of traditional PN fruiting bodies.
Antioxidant and Anti-Fatigue Properties: Extracted PN polysaccharides exhibited strong antioxidant activities, effectively neutralizing harmful free radicals (DPPH, ABTS, and hydroxyl radicals) and superoxide anions. These properties suggest that PN polysaccharides have potential to reduce oxidative stress, a key factor in fatigue.
Enhanced Physical Endurance in Animal Models: In vivo studies showed that PN polysaccharides improved endurance and resilience against physical fatigue in mice. The polysaccharides extended weight-loaded swimming time, boosted SOD (superoxide dismutase) enzyme levels, increased glycogen reserves in liver and muscle tissues, and reduced markers of oxidative stress, such as MDA (malondialdehyde) and LDH (lactate dehydrogenase). These findings underscore the potential of PN polysaccharides in mitigating fatigue through enhanced energy storage and oxidative protection.
Mechanism of Action via Nrf2/Keap1 Pathway: Researchers found that PN polysaccharides likely activate the Nrf2/Keap1 signaling pathway, which plays a crucial role in cellular antioxidant defense and regulation of oxidative stress. By modulating this pathway, PN polysaccharides help counteract fatigue at a molecular level.
A New Frontier for Functional Food Development
This study highlights a scalable approach to functional polysaccharide production using PN mycelium, creating a valuable resource for anti-fatigue and antioxidant health products. The optimized, high-yield liquid culture system offers a sustainable, accessible alternative to traditional PN cultivation methods, laying the groundwork for future research and product development.