Abstract: In this study, the effects of some rare earth elements such as La3+, Ce3+, Nd3+, Pr3+ and Er3+ on the production of polysaccharides and triterpenoids by liquid fermentation of Ganoderma lucidum were explored. The results indicated that obvious stimulation effects of these rare earth elements on the production of polysaccharides and tritepenoids were observed. Moreover, Pr3+ at concentrations of 0.01, 0.001 mmol/L and 0.1 mmol/L revealed the most obvious improvement on the production of intracellular polysaccharides (IPS), extracellular polysaccharides (EPS) and intracellular triterpenoids (IGT) with yields of 772.56, 452.76 mg/L and 398.49 mg/L, respectively. Compared with the control group, three components were increased by 4.67, 3.05 folds, and 1.91 folds due to Pr3+ treatment. However, La3+ at a concentration of 0.001 mmol/L showed a remarkable enhancing effect on EPS and the yield of EPS was up to 610.08 mg/L with a 2.03-fold enhancement. Therefore, the rare earth elements at appropriate concentrations can obviously increase the production of polysaccharides and triterpenoids in Ganoderma lucidum during liquid fermentation.

Key words: rare earth elements, Ganoderma lucidum, polysaccharides, triterpenoids