STUDIES ON pH CONTROLLED FERMENTATION OF BIOACTIVE EXOPOLYSACCHARIDES BY GANODERMA LUCIDUM

The effect of fermentation pH upon exopolysaccharides production by Ganoderma lucidum was studied in a 2L fermentor. The results showed that initial pH5.5 was favorable to exopolysaccharides production. Through an effective strategy of pH controlled fermentation at pH4.0, the maximum yield of exopolysaccharides, 2.32g/L, was obtained, and the yield of exopolysaccharides increased by 24% compared with the pH uncontrolled fermentation. The bioactivities of exopolysaccharides were also assayed. The results showed that exopolysaccharides could inhibit the growth of Sarcoma 180 in mice, and the average inhibition ratio (i.p. 10mg/kg for 10 days) was 51.2%; the immunological activity of mice could be significantly improved.