产多糖微生物的分离及所产多糖特性的研究
关键词 胞外多糖 筛菌 发酵 流变学特性 组分分析
毕业论文设计说明书外文摘要
Title Screening of polysaccharide-producing microorgranism and the properties of its polysaccharide
Abstract
Because of its safety and unique physicochemical properties, Microbial extracellular polysaccharide is widely used in various industries. A new strain JS01 was isolated from the soil from Yancheng City, Jiangsu Province. According to bacterial morphological identification and 16S rDNA analysis, the strain was identified as the genus Paenibacillus (Paenibacillus sp. JS01). We explored the optimal medium composition and culture conditions through a single factor experiment. The results showed that, the optimal conditions are sucrose 20g/L, peptone 5g/L, pH 9.0, temperature 30℃, broth volume 50 mL/250 mL. We also explored the impact of pH, temperature, salts and other factors on the rheological properties of polysaccharides. The results showed that, the viscosity keep stable basically when the pH is in the range of 5 to 9 and the temperature is below 70℃, respectively. The chemical compositions of the EPS extracted contain 66.88% sugar, 9.45% protein and other impurities. With high yield of EPS and easy to culture, Paenibacillus sp. JS01 will have great application potentials.
Keywords extracellular polysaccharide strain screening fermentation
rheological properties composition analysis
目 次
1 绪论 1
1.1 微生物多糖 1
1.2 微生物胞外多糖 1
1.3 微生物胞外多糖特性 2
1.4 胞外多糖的生理功能 3
1.5 微生物胞外多糖应用 5
1.6 本课题研究意义 7
1.7 本课题研究内容 7
2 实验部分 7
2.1 实验材料与试剂 7
2.2 产胞外多糖细菌的筛选及鉴定 9
2.3 Paenibacillus sp. JS01菌发酵条件优化 14
2.4 多糖流变学特性的研究 20
2.5 多糖的组成和组分的分析 23
3 总结与展望 25
3.1 实验总结 26
3.2 研究展望 26
结 论 28
致谢 29
参考文献30
1 绪论
多糖(polysaccharides)又名多聚糖，它是由醛糖或酮糖通过糖苷键连接成的聚合物，是一类由多个单糖或其衍生物聚合而成的大分子物质，通过一系列反应可以完全水解为单糖。多糖广泛参与细胞的生理过程的调节，参与生命骨架结构组成，是文持生命活动正常运行的重要部分，具有多种多样的生物学功能，例如抗肿瘤作用、免疫增强作用、降血糖、降血脂、抗病毒、抗细菌作用等。由于多糖特殊而良好的理化性质，在食品化工以及医药方面均有应用，随着分子生物学以及各种分析技术的发展，我们对其性质、结构以及生物活性就会有更深入研究，剖析多糖不同方面的生物学功能，以便更好的应用。