Enhanced Erinacine A Production by Hericium erinaceus Using Solid-State Cultivation

Abstract

Hericium erinaceus (HE) is a large edible medicinal fungus. Erinacine A (ErA) is a secondary metabolite presented in the mycelia of HE, with pharmacological effects as a nerve growth factor on the central nervous system. In this study, solid-state cultivation of HE was carried out in Petri dishes and glass jars for the production of mycelial biomass and ErA. The potato dextrose agar (PDA) had the highest mycelial biomass at an optimal temperature of 25 °C, but no ErA was found in the agar media. In glass jar cultivation, the mycelial biomass and specific yield of ErA in different substrates, particle sizes, substrate weights, nitrogen sources, and inorganic salts were investigated. The ErA was purified by a self-pack silica gel column and a semi-preparative HPLC and was identified by liquid chromatography-tandem mass spectrometer. The best conditions for solid-state cultivation of HE when using corn kernel as substrate, particle size less than 2.38 mm, and addition of 10mM ZnSO4, 7H2O, mycelial biomass of 50.24 mg cell dry weight/g substrate was obtained, in addition, the specific yield of ErA could reach 165.36 mg/g cell dry weight.

Isolation and Evaluation of Erinacine A Contents in Mycelia of Hericium erinaceus Strains

“…The low productivity of erinacine A has hindered its development and application as a dietary supplement. In the past, great efforts have been made to increase the productivity of erinacine A [ 8 , 21 , 42 , 43 ]. Using submerged cultivation, the highest content and yield of erinacine A were reported to be 14.44 mg/g and 225 mg/L, obtained by optimizing the culture medium composition [ 21 , 43 ].…”

“…Using submerged cultivation, the highest content and yield of erinacine A were reported to be 14.44 mg/g and 225 mg/L, obtained by optimizing the culture medium composition [ 21 , 43 ]. In addition, Cheng et al [ 8 ] reported that solid-state cultivation could significantly increase the content of erinacine A, reaching 165.36 mg/g. At present, there was no literature focusing on the comparison of erinacine A contents in different H. erinaceus germplasm resources, or screening the high-content strains or cultivars.…”

“…Erinacine A standard (purity > 95.0%) was generously provided by Prof. Chengwei Liu (Northeast Forestry University, Harbin, China). Erinacine A extraction was performed as described by [ 8 ] with minor modifications. The above-mentioned lyophilized mycelia of H. erinaceus were ground to powder, and then 1 kg of the powder was added into 75% ethanol ( w / v : 1/20) and extracted by ultrasonication for 1 h at 50 °C twice.…”

“…Pers., also known as lion’s mane mushroom, monkey’s head mushroom, or Yamabushitake, is a widely cultivated edible mushroom with a long history of use in traditional Chinese medicine [ 6 ]. Both the mycelia and fruiting bodies of H. erinaceus are rich in beneficial metabolites, including polysaccharides, erinacines, hericenones, and ergosterols [ 7 , 8 , 9 ]. Among all the culinary medicinal mushrooms, the nootropic properties of H. erinaceus have been especially well-documented, especially in their use in neuroprotection against neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases [ 10 , 11 ].…”

“…As one of the secondary metabolites, the content of erinacine A has shown marked variation among different strains [ 8 ], and was regulated by multiple genes. Therefore, the acquisition of H. erinaceus strains rich in erinacine A is essential to maximize its benefits.…”