The invention discloses a method of a culture medium formula for increasing content of
lentinan. The method comprises the following specific steps: preparing a culture medium, preparing a mother strain, preparing
fermentation liquor, adding Fe<2+> with a proper concentration, inoculating, standing and culturing at 25 DEG C for 60 d, and collecting mycelia to extract
polysaccharide; and preparing a cultivation bag, adding Fe<2+> with a proper concentration, inoculating,
mycelium growing, fruiting, collecting sporocarps, and extracting sporocarp
polysaccharide. Exogenous
metal ions with a proper concentration are added within optimal
induction time, growth of mycelia is promoted, expression quantity and
enzyme activity of a key
enzyme gene for
polysaccharide synthesis are improved, the polysaccharide content of the shiitake
mushroom mycelia is obviously improved, meanwhile, Fe <2+> with a proper concentration improves activity of a key
enzyme for sporocarp
polysaccharide synthesis, and the sporocarp polysaccharide content is increased. The method provides support for optimizing a shiitake
mushroom fermentation mode, improving the content of shiitake
mushroom mycelia and sporocarp polysaccharide and boosting development of shiitake mushroom
processing industry.