假蜜环菌产胞外多糖发酵的初步研究

在摇瓶和２１发酵罐水平上，研究了假蜜环菌产胞外多糖的发酵情况，并建立了一套方便可靠的检测方法。在摇瓶发酵中，探讨了培养基初始ｐＨ、初始糖浓度、装液量及钙离子等因素对假蜜环菌产生胞外多糖的影响，得出的优选条件为初始ｐＨ５．０，初糖浓度５％，每个５００ｍｌ瓶装液１００ｍｌ及添加１％碳酸钙。优选条件下在２１发酵罐中经７ｄ发酵后，胞外多糖产量可高达３．９９ｍｇ／ｍｌ。有关假蜜环菌胞外多糖的发酵研究，尚未见有报道。

A PRELIMINARY STUDY ON THE EXOPOLYSACCHARIDE PRODUCTION FROM THE FERMENTATION OF ARMILLARIELLA TABESCENS

Recent interest in the potential use of polysaccharides in medicine and pharmacology has stimulated work on the purification, characterization and pharmacological function of various kinds of polysaccharides from plants, fungi and bacteria. The polysaccharides from fungi are particularly attractive because of their unique advantages in the remedy of tumors and cancers.A fungus strain of Armillariella tabescens (" Luminous Fungus" ), preserved in our laboratory, was isolated from the luminescent decayed willow --wood at Dantu County of Jiangsu province in 1973. It was first found in our country that the extract of Ar. tabescenshad curative effects on cholecystities and Chronic hepatitis.Recently, it's reported that the intracellular polysaccharide of the Ar. tabescenshas an inhibitory effect on the mouse sarcoma S180, and can improve the organism's immunoactivity completely. In order to develop the polysaccharides of Ar. tabescensinto pharmaceuticals in future, a research project that included fermentation, purification, Characterization, analysis of chemical structure and pharmacological tests of the polysaccharides from Ar. tabescenswas initiated in our laboratory.This paper reports the preliminary study on the exopolysaccharide production from Ar.tabescens in a 2--liter fermentor and shaken flasks.At first, the entire course of the liquid fermentation in a 2--liter fermnetor was studied, a set of efficient detective methods of the exopolysaccharide, biomass and reductive sugar etc.were also estatblished here. In shaken flasks, the effects on exopolysaccharide production of the medium initial pH, initial glucose concentration, aeration (the medium volume in a flask ) and Ca ions were investigated. The resultant optimum conditions for exopolysaccharide production were an initial pH of 5, 5% glucose and 1% CaCO in the medium, 100ml medium in per 500ml flask. Under the optimal conditions, the yield of exopolysaccharide was 3. 99mg/ml high after seven days' fermentation. There have few reports on this subject up to now/