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

黑柄炭角菌Xylaria nigripes(K1.)Sacc.是著名的滋补药用真菌,尤其是菌核部位生长在白蚁废弃的蚁巢中,生态条件特殊,资源稀少,研究和开发该菌具有重要意义。为了提高黑柄炭角菌菌丝体和多糖的产量,以便于组织工业化生产,本文探索了该菌的营养条件,测定其生长过程中菌丝体和多糖形成的动态变化,并研究了酯酶同工酶谱和多糖含量变化的相关性。结果表明:在深层培养时,碳源以葡萄糖、淀粉最佳;花生、黄豆、蛋白胨是适宜菌丝生长的良好氮源;Mg~(2+),Zn~(2+)等是其生长的必需元素;有机酸中仅柠檬酸对其菌丝生长有促进作用,在蚁酸影响下,pH值为4.0时,菌丝生长受抑制。在上述实验基础上,进行了产多糖和菌丝体的适宜培养基筛选试验,在适宜条件下,能培养出密集、白色、均匀的菌球和丰富的多糖,经4天培养的培养液中粗多糖量可达15.35g/L,菌丝干重为26.89g/L,符合了工业化生产要求。该菌的菌丝体酯酶同工酶谱较稳定,均为二条酶带,但它们的酶活性有所不同,与菌丝体生长的天数有关。并与多糖含量变化具有一定关系。

SUBMERGED CULTURE AND PHYSIOLOGY OF XYLARIA NIGRIPES,ON TERMITE NEST

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.