【作者】 冀颐之；

【导师】 杜连祥；

【作者基本信息】 天津科技大学 ， 发酵工程， 2003， 硕士

【摘要】 本文对裂褶菌胞外多糖的发酵条件，提取工艺及结构进行了研究，确定了裂褶菌产糖的最佳培养基、培养条件、提取工艺条件及多糖的结构。研究的主要内容和结论如下： 1．在裂褶菌胞外多糖的发酵研究中通过单因子试验和正交试验确定了裂褶菌产糖的最优培养基配方为：葡萄糖45g/L，酵母膏3g/L，KH₂PO₄ 0.5g/L，MgSO₄·7H₂O 0.5g/L；最适发酵条件为：接种龄66h，接种量10％，培养温度27℃，装液量20％，初始pH自然。得到摇瓶条件下菌体最大得率20.75g/L，胞外多糖最大得率2.70g/L。经7L发酵罐的分批发酵得到菌丝干重产率为8.81g/L，胞外多糖产率为0.84g/L。多糖与菌体比为1:10。补水稀释发酵试验结果为菌丝干重得率19.98g/L，裂褶菌胞外多糖得率1.89g/L，分别为分批发酵的2.27倍和2.25倍，而多糖菌体比未变。 2．对裂褶菌胞外多糖的提取工艺进行了初步研究。确定了最佳的脱色方法为活性碳吸附法，最适加量为0.5％。最佳脱蛋白方法为等电点法与Sevag法2次相结合的方法。工艺路线为：发酵液→除去菌体→活性碳脱色→浓缩→脱蛋白→乙醇沉淀→复溶→沉淀→纯裂褶菌胞外多糖 3．进行了裂褶菌胞外多糖的结构分析。由凝胶柱层析，聚丙烯酰胺凝胶电泳，高效液相色谱分析可知裂褶菌胞外多糖为均一组分，分子量4×10⁴u。通过完全水解，纸层析，气相色谱分析单糖组分，红外光谱，酶解反应，高碘酸氧化和固体核磁共振分析结构，证明了裂褶菌胞外多糖是以葡萄糖为单一组分的β-（1-3）-D葡聚糖，其中每三个葡萄糖分子上连有一个β-（1-6）的分支。更多还原

【Abstract】 The fermentation conditions, the extraction methods and the structure of schizophyllan were studied in this thesis. The main contents and results were as follows:Fermentation schizophyllan by Schizophyllum commune was optimized. The results of single factor and orthogonal experiment showed that the optimized medium composition contained: glucose 45g/L,yeast extract 3g/L,KH2PO4 0.5g/L,MgSO4.7H2O 0.5g/L. The optimized conditions were inoculum age 66h,inoculum size 10%,temperature 27 C,volume of medium 20% and pH 6.Maxium yield of schizophyllan and mycelium of flask were 2.70g/L and 20.75g/L respectively .But the yields of schizophyllan and mycelium were 0.84g/L and 8.81g/L respectively in batch culture. The result of water-fed experiment showed that the yields of mycelium and schizophyllan were greatly improved and them were 19.98g/L and 1.89g/L respectively.The extraction method of exo-polysoccharide from schizophyllum commune by submerged cultivation was studied. The extraction technology was improved and the best methods of removing color and Proteins were achieved.The structure of schizophyllan from schizophyllum commune by submerged cultivation was also researched. The purified schizophyllan was proved to be homogeneous with molecular weight 4 + 104u by sephadex G-200 column chromatography, PAGE and HPLC. Its monomer was determined by hydrolysis, PC, GC and its structure was analyzed by IR, enzymolysis, periodate oxidation, CP/MAS13C NMR, the results showed that schizophyllan was only composed of glucose and it consisted of a backbone chain of 1,3-B-D-glucopyranose units linked with single 1,6-B-D-glucopyranoses at about every third glucose molecule in the basic chain.更多还原