Abstract:

Pyrofomes demidoffii is a newly recorded species of a newly recorded genus in China, and it is also a rare medicinal mushroom. To find a both high yield and economical medium for the mycelial growth of Pyrofomes demidoffii, several culture conditions including carbon source, nitrogen source, C/N ratio, rational speed, culture temperature, initial medium pH value, the volume of medium in the fermentation vessel and inoculum amount were investigated through single factor experiments and the effects of three medium components and pH on the mycelial growth of Pyrofomes demidoffii were analyzed by multifactor uniform design. The above investigations were performed using a liquid medium. The optimum carbon source, nitrogen source and C/N ratio for the mycelial growth of Pyrofomes demidoffii were starch, wheat bran and 20:1－25:1. The mycelial growth of Pyrofomes demidoffii was promoted by P, K and Mg. A pH range between 5 and 7, the volume of medium in the fermentation vessel of 100mL and inoculum amount of 8 mL/100mL were found optimum. The optimum composition of the liquid medium used consisted of glucose 25 g/L, bran 125 g/L and K2HPO4 0.25 g/L, pH 6.5. The mycelial growth of Pyrofomes demidoffii could be described by the logistic equation: y = 0.22/(1+1.019e － 0.013x).

Key words: Pyrofomes demidoffii, liquid-state fermentation, mycelial yield