Study on the Selenium Enrichment Characteristics and Deep Fermentation of Hericium erinaceus Mycelium
Selenium is an essential trace element for the human body, mainly involved in the formation of glutathione peroxidase (GSH Px), thioredoxin reductase (TrxR), selenoprotein P (Selp) in the body, regulating oxidative stress, redox status, and key cellular activities. Selenium mainly exists in nature as inorganic selenium and organic selenium, among which the safety range of inorganic selenium is very small. Edible fungi have strong selenium enrichment ability and can convert inorganic selenium into organic selenium that can be absorbed and utilized by the human body. Edible fungi commonly use fruiting body culture or deep fermentation mycelium culture. Compared with traditional fruiting body culture, deep fermentation has the advantages of less land occupation, lower cost, higher yield, controllable quality, good repeatability, and environmental friendliness. At present, the addition of inorganic selenium to liquid culture medium and deep fermentation cultivation of selenium rich edible mushroom mycelium to extract selenium rich products (such as selenium rich polysaccharides) have been widely used.

Hericium erinaceus (Rull ex F.) Pers belongs to the Basidiomycota phylum, Agaricales class, Russula order, and Serranidae family. In addition to its delicious taste and rich nutrition, it also has the effects of lowering blood sugar, antioxidation, anti-aging, promoting peripheral nerve regeneration, inhibiting tumor cell growth, and enhancing immune regulation ability. It has significant effects in the treatment of gastric ulcers and gastrointestinal cancer. As a delicious, nutritious, and effective edible mushroom, Hericium erinaceus is a high-quality material for selenium rich cultivation. However, currently, the selenium rich cultivation of Hericium erinaceus is mostly limited to the cultivation of fruiting bodies, and there are few reports on deep fermentation cultivation of selenium rich Hericium erinaceus.

This article studied the selenium enrichment ability of three types of Hericium erinaceus and screened selenium tolerant strains; Optimize the types and ratios of carbon sources, nitrogen sources, inorganic salts, and vitamins for deep fermentation cultivation; Determine the amount of inorganic selenium added to the culture medium to obtain selenium rich mycelium of Hericium erinaceus, providing experimental basis for the development and utilization of selenium rich Hericium erinaceus products.

Among the three types of Hericium erinaceus, H2 has the strongest selenium tolerance. The mycelium is cultured in Na2SeO3 solid medium containing 6 μ g/mL and can be used as a strain for subsequent deep fermentation; The composition of the deep fermentation medium for Hericium erinaceus is: soluble starch 5.8%, soybean powder 5.8% CaCl2 0.04%、VB1+VB2+VB6 0.024%， Adding 12 μ g/mL Na2SeO3 to this culture medium resulted in good mycelial growth and the highest total selenium and organic selenium content. In summary, the deep fermentation of Hericium erinaceus mycelium can achieve high yields and has strong selenium enrichment ability, which has the potential for development and utilization.