SUBMERGED CULTURE AND PHYSIOLOGY OF XYLARIA NIGRIPES,ON TERMITE NEST
白蚁巢上生长的子囊菌——黑柄炭角菌的深层培养及其生理研究

Xylaria nigripes (Kl.) Sacc. is a well-known nourishing medicinal, fungus. It grows in the abandoned termite nest and is rare in the nature. This paper explores the nutrient conditions which effect the yields of the mycelia of Xylaria nigripes, measures the dynamic variation in the formation of the mycelia and polysaccharide of Xylaria nigripes, and examines the correlation between the characteristics of esterase isozyme and the polysaccharide contents of Xylaria nigripes. It is found that glucose, starch and fructose are the most suitable carbon sources, for the mycelia to grow. Peptone, peanut meal and soybean meal are found to be preferable nitrogen sources, with peanut meal or soybean meal better than peptone, and Mg++ and Zn++ the essential elements. Among several organic acids, only citric acid is found to promote the growth of the mycelia of Xylaria nigripes. Formic acid (pH = 4.0) constrains the growth of the mycelia of Xylaria nigripes, which is consistent with the fact that Xylaria nigripes do not .grow in the termite nest where formic acid is present. Based on the experiments mentioned above, we selected the suitable medium for producing the mycelia and polysaccharide with the biostatistic method. In the suitable medium, a dense suspension of Xylaria nigripes with numerous white homogeneous mycelia pellets and abundant polysaccharide is successfully produced. Under optimal conditions, the yields of polysaccharide reach 15.35g/L. and that of mycelia reach 26.8g/L in culture liquid within 4 days, which meets the requirement of industrial production. The esterase "isozyme patterns are stable and maintain 2 bands under different cultural conditions and growing stages. The esterase activity, however, is found to be correlated with the growing days of mycelia and the polysaccharide contents of Xylaria nigripes.