Biological Characteristics, Nutritional Composition, and Heavy Metal Safety of Mycelia from Gerhardtia borealis, a Rare Wild Edible Fungus

The orthogonal design further optimized the culture medium to a combination of ammonium nitrate, sucrose, and magnesium sulfate, achieving a mycelial growth rate of 1.379 mm/d. The mycelia of Gerhardtia borealis contained 26.01% crude protein, 6.03% crude fat, and 1.24% crude polysaccharides. A total of 17 amino acids were detected, with a total content of 26.09 g/kg. The iron and zinc contents in the mycelia were 28.09 mg/kg and 22.17 mg/kg, respectively. The concentrations of arsenic, cadmium, mercury, and lead were all below the national food safety limits. This study provides fundamental data supporting the domestication and functional utilization of Gerhardtia borealis as an edible and medicinal resource.