The optimal extracellular polysaccharide (EPS) producing time and its composition of a fungal strain were studied through determining the content of EPS in the fermented broth and the viscosity of supernatant,to confirm the optimal sugar producing time,and adopted this condition to extract crude EPS.The content of extracted crude EPS was determined with anthrone chromometry,its components were analyzed with thin layer chromatography.The results showed that when the fermentation was at day 5 the fungal biomass and EPS production and the broth viscosity reached to the peak,respectively at 0.606 4 g/60 mL,20.22 μg/mL and 4.74 mPa/s,and the EPS content and the fermentation broth viscosity assumed to be positive reciprocity to a certain degree.The content of the extracted crude EPS was 19.58 μg/mL by anthrone chromometry.After the completely hydrolyzed by 4 mol/L sulfuric acid,the hydrolysate was analyzed with silica gel G thin-layer chromatography,while dispersed with methanol:chloroform (1:1) developed with aniline-diphenylamine,indicated that its components probably were D-mannose,D-galactose and D-glu-cose.The EPS,which confirmed to have improve crust and the prevention and water retention ability,can provides theoretical basis and neoplasm resources for their further use.%探究一株真菌胞外多糖最佳生产时间及其组成成分.通过对其发酵液胞外多糖含量及上清液黏度的测定,确定其最佳产糖时间,并用此条件提取胞外多糖粗品,用蒽酮-比色法测得提取的胞外多糖粗品的糖含量,薄层色谱法对所得的胞外多糖进行组分分析.当发酵至第5天时该株真菌的生物量、胞外多糖产量及发酵液的黏度均达到最高峰,分别为0.606 4 g/60 mL、20.22 μg/mL和4.74 mPa/s,并且胞外多糖含量与发酵上清液黏度在一定程度上呈正相关.用蒽酮-比色法测得提取的胞外多糖粗品的糖含量为19.58μg/mL,并用4 mol/L的硫酸完全水解,硅胶G薄层层析,甲醇-氯仿(1∶1,体积比)展层,苯胺-二苯胺-磷酸显色,表明其组成成分可能为D-甘露糖、D-半乳糖和D-葡萄糖.该菌株所产的胞外多糖具有提高结皮能力和防沙保水作用,为利用微生物治沙提供参考和种质资源.
展开▼
