Rare earth elements, such as Lanthanum, at certain concentration may exhibit its specific activity to promote the growth
of plants and microbes. But studies on its application to increase the yield of
polysaccharide of cultured Hericium erinaceus (Fr. ) Pers. has not been reported in literatures. Different
concentrations of La(NO 3) 3 were added to the culture medium of H. erinaceus mycelium. Inoculate a Φ 0 5 cm size, 10 d cell age colony into the fermentation medium containing different concentrations of La(NO 3) 3 and culture for 7 d Collect the supernatant liquid and determine the polysaccharide content after centrifugings extraction and hydrolysis. It was found that La(NO 3) 3 at a concentration of 0 5 mmol/L can increase the extracellular polysaccharide content to 126.69% of the control, while at a concentration of 0 75 mmol/L, the water soluble polysaccharide content of the mycelium is raised by 19.4%, and increased the sodium hydroxide soluble polysaccharide content by 4.71%. It could be concluded that La(NO 3) 3 at concentrations of 0 5～0 75 mmol/L can promote the yield of polysaccharides in H. erinaceus cultural medium.