【作者】 赵金；

【导师】 连宾； 周文美；

【作者基本信息】 贵州大学 ， 发酵工程， 2006， 硕士

【摘要】 研究了一株絮凝效果好的胶质芽胞杆菌(Bacillus mucilaginosus)BM01菌株产微生物絮凝剂(MBF)的絮凝作用及絮凝机理。 对BM01菌株培养研究得出该菌株产絮凝剂最佳培养周期为5天；由BM01菌株生长曲线和絮凝率随时间变化曲线的同步对比得出参与絮凝的活性物质应为该菌株的代谢产物，而非细菌细胞本身；絮凝活性物质在培养液中分布测定结果表明细菌—矿物复合体中的絮凝活性物质含量略多于上清液中的絮凝活性物质含量。 对BM01菌株产絮凝剂的最佳培养条件进行单因子试验、正交试验，结果表明：蔗糖为碳源且含量为5‰，矿粉添加量为2.5‰，培养基初始pH值为7.0，处理3‰的高岭土悬浊液，BM01菌株产絮凝剂(MBF-BM01)的絮凝率最高为95.2％。 单因子试验、正交试验研究表明：MBF-BM01对生活废水处理的最佳条件为絮凝剂投加量为6mL／100mL废水，体系pH值为9，絮凝时间为6h，絮凝率最高为94.24％。 利用紫外光谱和红外光谱扫描分析等测试手段对MBF-BM01所提取出的生物大分子物质进行检测，结果表明MBF-BM01的絮凝有效成分主要是酸性多糖，属阴离子型絮凝剂；利用MBF-BM01对高岭土颗粒的絮凝作用作为研究胶质芽胞杆菌絮凝作用机理的研究模型，通过对絮凝体系中粒径分布检测及透射电镜观察结果表明，絮凝剂分子和高岭土颗粒之间可通过“架桥”作用发生絮凝并最终导致沉淀。其大致的作用过程是：在絮凝作用发生初期，首先是范德华力克服了由带同种电荷产生的静电斥力，致使MBF-BM01生物大分子与高岭土颗粒间相互靠近，随着距离的缩短，氢键为其主要吸附作用力，同时带负电的絮凝剂分子也受到高岭土晶体边缘正电荷区的吸引而发生吸附，最后在“吸附—架桥”作用下导致沉淀。 微生物絮凝剂安全、无毒、可生物降解、无二次污染，因此在污水处理、物质分离等方面都表现出其它无机类、有机类絮凝剂无法相比的优点。胶质芽胞杆菌与其他絮凝剂产生菌株相比，对营养条件要求低、容易培养和鉴别，这在很大程度上降低了其生产成本，因而具有更广阔的应用前景。更多还原

【Abstract】 This paper studied flocculating effect and flocculating mechanism of the Microbial Flocculant (MBF ) produced by a strain of Bacillus mucilaginosus BM01, which had good flocculabilities.The result of research on cultivating strain BM01 showed that the prime culture period of strain BM01 producing MBF was 5 days; We educed the conclusion that the flocculating active component should be metabolites of the strain but not bacterial cell; The result of determining the distribution of flocculating activities in culture indicated that the flocculating activities content of Bacteria—mineral composition was higher than that of supernatant culture slightly.Single factor experiment and orthogonal experiment were studied on the culture conditions of stain BM01 producing flocculant, and the results suggested that sucrose was used as carbon sourse which the content of was 5‰ ,and the content of the clay mineral poweder was 2.5‰. In addition, the flocculating rate of MBF-BM01 arrived at 95.2% at pH7 of medium, when we disposed of 3‰ Kaolin clay suspension liquid.The results were showed by single factor experiment and orthogonal experiment researcheded on the optimal condition of MBF-BM01 treating with domestic waste water as follows: flocculant addition was 6mL/100mL waste water, pH value of flocculating system was 9 and the flocculating time was 6 hours. In the conditions stated hereinbefore, MBF-BM01 can get a highest flocculating rate 94.24%.We detected the biomacromolecule extracted from MBF-BM01 by UV , IR testing means and so on, and the results were showed as follows: the major effective components of MBF-BM01 were acidic polysaccharide, which were of an anionic flocculant; Reaseach model of Bacillus mucilaginosus flocculating mechanism was studied by MBF-BM01 effecting on Kaolin, furthermore, the inspection of particle-size distribution in flocculating system and the observation by TEM indicated that the flocculation molecule and kaolin microparticle could flocculate by "bridge", finally deposited. The process can be described roughly: at the beginning of flocculation, the Van der Waals force overcame the electrostatic repulsion that occured between the same kind of charge, and caused the biomacromolecular of MBF-BM01 and the kaolin microparticle to close up; along with the abridgement of更多还原