Abstract:

To promote mycelium growth and polysaccharide biosynthesis in Phellinus igniarius, different groups (sugar and plant oil) of precursors were added to synthetic complete medium and the effects of the kind and amount of separately added sugars and plant oils on Phellinus igniarius mycelium growth and polysaccharide biosynthesis were dealt with. A two-factor, threelevel full combination design was used to optimize the conditions for lactose supplement, and the results showed that a maximum mycelium biomass of up to 13.18 g/L and a maximum polysaccharide production of up to 1.21 g/L were achieved after 168 h fermentation in a 3 L fermentor with an initial lactose concentration of 30 g/L, and the increment percent of polysaccharide production was 25% in comparison with the control. Among oils from three plants, including soybean, olive and rapeseed, rapeseed oil most obviously promoted the growth of Phellinus igniarius mycelia, and the maximum mycelium biomass was up to 23.77 g/L after fermentation for 144 h in a 7 L fermentor, 207.1% higher than that obtained from the control, while polysaccharide biosynthesis was inhibited by adding rapeseed oil.

Key words: precursors, Phellinus igniarius, mycelia growth, polysaccharide