The medicinal mushroom for the microbiota
Pleurotus eryngii (or King Oyster mushroom) is a medicinal mushroom of significant scientific interest for its polysaccharide composition (with interesting prebiotic activity), but also for its high mineral, phenolic and vitamin content. This species is one of the most sought after by mushroom enthusiasts as it is highly valued as a culinary mushroom due to its organoleptic qualities. It is easily found in meadows and fields, usually where wild thistles, Sea Holly (Eryngium campestre) and other umbellifers grow. In addition to ‘seta de cardo’ or ‘eryngii’, this variety is known as ‘Gardu Ziza’ in the Basque Country, ‘Gírgola de panical’ in Catalonia and ‘Seta de cemtcamps’ in Valencia.
Essential notes on Pleurotus eryngii
P. eryngii stands out for the amount of active biomolecules it contains, especially β-glucans (immunomodulatory polysaccharides) and minerals such as potassium and phosphorus. It also contains phenolic compounds or ergothioneine, which have a natural antioxidant function. Thanks to these and other biomolecules, the king oyster mushroom is the subject of ongoing scientific research in health-related areas such as:
- Gastroenterology: gastrointestinal or digestive health
- Immune system support
- Integrative oncology support
P. eryngii is an edible and medicinal species found in Western Europe, Central Europe, Central Asia and Southwest Russia. It is one of two species of the genus Pleurotus (alongside Pleurotus ostreatus) most valued for its nutritional and functional qualities. Like most basiodiomycetes fungi used in traditional medicine, researchers studied its composition by uncovering its lignocellulosic enzyme complexes. They found a large number of substances with potent therapeutic properties, suggesting their usefulness for medicinal and biotechnological applications. This has led to the expansion of king oyster cultivation and much research into its function as a nutraceutical: it contains compounds that enhance the growth of beneficial bacteria naturally present in the colon.
Properties, applications and uses of P.eryngii
Like Shiitake or Maitake, the consumption of King Oyster mushroom has evolved from a food use to a functional food use due to its gut microbiota regenerative action. Recently, mushrooms have been recognised as an excellent source of bioactive substances for the pharmaceutical industry, in particular polysaccharides (including beta-glucans). In fact, polysaccharides from P. eryngii are increasingly attractive for their activity.
For example, a polypeptide (PEMP) extracted from P. eryngii showed significant antioxidant and macrophage-mediated immune response activating activity in a number of different cells. Although the nutrients of interest in this mushroom can be consumed through food, to achieve a higher concentration and effect on the body, it is necessary to consume it as a powder or extract (in capsules), where high concentrations of active biomolecules can be obtained. P. eryngii powder can be found, combined with other species, in formulas such as Bio-Defense and Bio-Intestin.
The basidiomycete P. eryngii is rich in protein, polysaccharides, unsaturated fatty acids, vitamins and other nutrients, and low in fat, making it a high-quality, low-calorie food. In addition, P. eryngii is also a rich source of the disaccharide trehalose. P. eryngii has a number of nutrients of functional interest, active biomolecules of which the most important are:
Other peptides and fatty acids
Some of these compounds have been shown to enhance in vitro growth of certain bacteria naturally present in the colon, Lactobacillus, Bifidobacterium y Enterococcus.
The morphology of P.eryngii is similar to that of P. ostreatus. Its cap ranges from 4 to 10 cm and the predominant colour of the cuticle is brown, which lightens as it matures. Its gills are initially white and then darken to a cream colour. The flesh is white, more consistent than in other Pleurotus species, with a pleasant smell and sweet taste. The large stalk is one of the most characteristic elements of this species. It is white, without a ring and the flesh is firm.
Cultivation of the king oyster mushroom
It is commonly cultivated in Europe, the Middle East and North America, as well as in many parts of Asia. Cultivation has been undertaken, but on a smaller scale than P. ostreatus.
P. eryngii fruiting bodies are easy to grow with a yield and the products have a large market due to their good taste and medicinal potential. In recent years, the extraction of polysaccharides from the fruiting bodies, mycelium and fermentation broth of edible mushrooms has become an active research topic in order to explore their structure and physiological activities. There are many strains of P. eryngii in the world, which are widely cultivated.
Different P. eryngii strains react differently to different substrates. It can be easily and successfully cultivated on substrates such as wheat straw, rice, sawdust, etc. However, cultivation on organic gorse (Ulex europeus) substrate provides high yields.However, if production is aimed at improving human health, more sophisticated systems with controlled environments, and organic substrates, etc. are used.
Cultivation in bioreactors
Highest quality, purity and performance in our production systems
One of the most powerful lines of research at Hifas da Terra focuses on the continuous improvement of the cultivation of different species in bioreactors (Reishi, Lion's Mane, Shiitake and Maitake) using certified organic substrates, as well as the standardisation of the quality of source ingredients to guarantee excellence in the final product with each medicinal mushroom.
Through our own quality standards, we identify biomolecules and active ingredients with therapeutic actions, selecting the fungal strains that contain the optimum amounts, and use our own specific analytical systems to apply analysis protocols at different stages of production. Thanks to this rigorous system, we offer natural products, supplements and nutraceuticals with the Hifas Quality System guarantee, setting us apart from other products in terms of quality, safety and efficacy.
R&D and studies using P.eryngii
- The R&D team at Hifas da Terra carried out a study on the optimisation of the extraction processes of active biomolecules in P. eryngii to obtain fractions with antioxidant properties: Innovative technologies for the extraction of saccharidic and phenolic fractions from Pleurotus eryngii, published in LWT – Food Science and Technology.
- Thanks to its antioxidant-rich composition (especially in ethanolic extracts), researchers consider P. eryngii extract to be highly suitable for the formulation of anti-ageing creams.
- King Oyster appears in the writings of Pliny the Elder (23-79 AD), who provides information on the use and collection of the mushrooms that live on the roots of the thistle, P. eryngii
- The books Comer para vencer el cáncer, by Dr Paula Jiménez Fonseca, medical oncologist and Belén Álvarez Álvarez, nutrition chemist, and Mi Alimentación Anticáncer, by Dr Odile Fernández, devote a chapter to medicinal mushrooms, which includes reference to pleurotus species
- Krüzselyi, D., Kovács, D., Vetter, J. (2016). Chemical analysis of oyster mushroom (Pleurotus eryngii) fruiting bodies. Acta Alimentaria, 45(1), 20-27. doi:10.1556/066.2016.45.1.3.
- Stajic, M., Vukojevi, J., Duletic-Lauševic S. (2009). Biology of <i>Pleurotus eryngii</i> and role in biotechnological processes: a review. , 29(1), 55-66. doi:10.1080/07388550802688821.
- Sun, Y., Hu, X., & Li, W. (2017). Antioxidant, antitumor and immunostimulatory activities of polypeptide from Pleurotus eryngii mycelium. International journal of biological macromolecules, 97, 323-330. https://doi.org/10.1016/j.ijbiomac.2017.01.043.
- Wong, Jack Ho., et al (2020). Fungal extracts and compounds with suppressive action on breast cancer: evidence from studies with cultured cancer cells, tumour-bearing animals and clinical trials. Applied Microbiology and Biotechnology, (), -. doi:10.1007/s00253-020-10476-4.
- Xue, Zhaohui; Li, Jiaomei; Cheng, Aiqing; Yu, Wancong; Zhang, Zhijun; Kou, Xiaohong; Zhou, Fengjuan (2015). Identification of triterpene structure of Pleurotus eryngii mushroom with inhibitory effects against breast cancer. Plant Foods for Human Nutrition, 70(3), 291-296. doi:10.1007/s11130-015-0492-7
- Yang, RL, Li, Q. and Hu, QP. Physicochemical properties, microstructures, nutritional components and free amino acids of Pleurotus eryngii as affected by different drying methods. Sci Rep 10, 121 (2020). https://doi.org/10.1038/s41598-019-56901-1
- Zhang, Bingru; Li, Yanying; Zhang, Fuming; Linhardt, Robert J.; Zeng, Guoyang; Zhang, Anqiang (2019). Extraction, structure and bioactivities of Pleurotus eryngii polysaccharides: a review. International Journal of Biological Macromolecules, (), S0141813019338218-. doi:10.1016/j.ijbiomac.2019.10.144.