Assessment of phylogenetic, growth, and antioxidant capacity of Pleurotus spp. in Malaysia

Effect of Culture Media on the Yield and Protein Content of Pleurotus ostreatus (Jacq.) Kumm Mycelia

The development of alternative proteins derived from fungi-based sources is gaining recognition due to their health benefits and lower environmental impact, compared to traditional animal-based sources. In this study, we investigated the culture conditions for Pleurotus ostreatus mycelia, focusing on the nutritional requirements and yield optimization using solid surface culture and liquid-state culture methods. Our findings indicate that optimal culture conditions involve glucose as the primary carbon source, with an initial pH of 6.0. By the eighth day of the culture period, media formulated with amaranth seed flour and Bambara groundnut flour yielded the highest mycelial protein content, characterized by a compact filamentous network with fewer open pores. Additionally, urea supplementation at 0.01% concentration on amaranth seed-based nutrient medium significantly increased the protein content from 31.4% to 38.7% (dry weight basis). The research findings contribute to the development of fungal-based proteins, which are essential in the production of sustainable food products.

GastronOmics: Edibility and safety of mycelium of the oyster mushroom Pleurotus ostreatus

Food production is one of the most environmentally damaging human activities. In the face of climate change, it is essential to rethink our dietary habits and explore potential alternative foods catering both towards human and planetary needs. Fungal mycelium might be an attractive alternative protein source due to its rapid growth on sustainable substrates as well as promising nutritional and organoleptic properties. The natural biodiversity of filamentous fungi is vast and represents an untapped reservoir for food innovation. However, fungi are known to produce bioactive compounds that may affect human health, both positively and negatively. To narrow the search for safe and culinarily attractive fungal species, mycelia of edible fruiting-body forming fungi provide a promising starting point. Here, we explore whether the culinary attractiveness and safety of the commonly eaten mushroom, Pleurotus ostreatus, can also be translated to its mycelium. Whole-genome sequencing and pan-genome analysis revealed a high degree of genetic variability within the genus Pleurotus, suggesting that gastronomic traits as well as food safety may differ between strains. A representative strain, P. ostreatus M2191, was further analyzed for the food safety, nutritional properties and culinary applicability of its mycelium. No regulated mycotoxins were detected in either the fruiting body nor the mycelium. Yet, P. ostreatus is known to produce four peptide toxins, Ostreatin, Ostreolysin and Pleurotoysin A/B. These were found to be lower in the mycelium compared to fruiting bodies, which are already considered safe for consumption. Instead, a number of secondary metabolites with potential health benefits were detected in the fungal mycelium. In silico analysis of the proteome suggested low allergenicity. In addition, the fruiting body and the mycelium showed similar nutritional value, which was dependent on the growth substrate. To highlight the culinary potential of mycelium, we created a dish served at the two-star restaurant the Alchemist in Copenhagen, Denmark. Sensory analysis of the mycelium dish by an untrained consumer panel indicated consumer liking and openness to fungal mycelia. Based on sustainability, safety, culinary potential, and consumer acceptance, our findings suggest that P. ostreatus mycelium has great potential for use as a novel food source.

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.