灵芝胞外生物活性多糖的pH控制发酵

灵芝深层发酵过程中 ｐＨ值对灵芝胞外多糖形成的影响。结果表明起始ｐＨ为５．５时，有利于胞外多糖的形成，找到了一种有效的ｐＨ控制发酵策略，当发酵过程中控制ｐＨ４．０时，胞外多糖的产量最大，达到２．３２９／Ｌ，较未控制提高了２４％。另外，还对胞外多糖的生物活性进行了检测，结果表明抗肿瘤活性平均达到５１．２％，且能明显提高小鼠的免疫力。

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.