新型改性壳聚糖灭菌微球的制备及初步应用

发布时间：2018-01-11 08:27

本文关键词：新型改性壳聚糖灭菌微球的制备及初步应用　出处：《浙江工商大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着社会的快速发展,人们生活质量越来越高、安全意识越来越强。饮用水安全一直是全社会关注的热点,尤其是由微生物污染所引起的安全问题。解决该问题的方法主要有两类:高温灭菌和使用化学消毒剂。但是,前者成本高、耗能大、使用不便;后者会残留令人讨厌的气味,存在"二次污染"的风险。因此,开发既安全又高效,同时成本价格也低廉的灭菌剂成为研究的重要方向。固定化灭菌技术就是将具有抑菌作用的杀菌基团固载于某种不可溶性载体的灭菌方法,体现了常温灭菌且低能耗、低残留的优势。本文在综述了固定化杀菌剂种类及壳聚糖改性研究现状基础上,选用壳聚糖为实验材料,采用反相悬浊液法,制得交联壳聚糖微球,将杀菌功能基通过一定的方式与交联壳聚糖微球反应合成新型改性灭菌微球,并利用元素分析法得出最佳合成条件。通过对受试菌的最小抑菌浓度(MIC)、最小杀菌浓度(MBC)的测试,筛选出杀菌性能优异的灭菌微球,并对其进行初步的性能研究和实际应用。主要研究内容如下:1.壳聚糖与环氧氯丙烷交联,在单因素条件实验下,以交联微球为母体,引入杀菌功能基配体,合成新型改性灭菌微球。利用元素分析得出灭菌微球的含氮量(N%),计算四种新型改性微球的转化率,并根据每种微球的转化率判断最佳反应溶剂、反应温度及反应质量比。在最佳合成件下,ABTC、APC、DMTC和CCC的转化率分别为39.4%、42.9%、33.1%和44.2%。利用红外光谱对改性微球的结构进行表征,推断微球合成路线,并利用热重分析法考察微球的热稳定性。2.通过对大肠杆菌(Escherichia coil)和金黄色葡萄球菌(Staphylococcus aureus)的最小抑菌浓度(MIC)及最小杀菌浓度(MBC)的测定,考察改性微球的灭菌效果。结果表明ABTC和CCC杀菌效果最好。为了进一步了解灭菌微球的性能,探讨了 Ag+、Cu2+对微球灭菌效果的影响,结果表明ABTC和CCC微球仍能保持良好的杀菌性能。3.以ABTC和CCC为灭菌微球代表,对胞外DNA和RNA、TTC-脱氢酶活性进行测定,深入探讨微球灭菌机理,并对其金属吸附及灭菌进行重复使用性测试。两种微球对金属离子吸附重复使用5次后仍能将吸附率维持在95%以上;作为高效杀菌剂时,可重复使用2次。通过热重分析表征,考察此时微球热稳定性的变化。4.以正常流动速度将含有微生物的饮用水通过ABTC和CCC改性灭菌微球制成的灭菌柱,测试结果直接证明ABTC和CCC改性灭菌微球具有良好的杀菌效果。
[Abstract]:With the rapid development of society, people's quality of life is getting higher and higher, safety consciousness is becoming stronger and stronger. Drinking water safety has always been the focus of attention of the whole society. Especially the safety problem caused by microbial contamination. There are two main ways to solve this problem: high temperature sterilization and chemical disinfectant. However, the former is costly, energy consuming and inconvenient; The latter has the risk of "secondary pollution" with unpleasant odors. Therefore, development is both safe and efficient. At the same time, the low cost of sterilizing agent has become an important direction of research. Immobilized sterilization technology is to immobilize the bactericidal groups with bacteriostasis on an insoluble carrier. Based on the review of the kinds of immobilized fungicides and the present situation of chitosan modification, chitosan was selected as the experimental material and the reverse phase suspension method was adopted. The cross-linked chitosan microspheres were prepared. The bactericidal functional groups were reacted with cross-linked chitosan microspheres in a certain way to synthesize new modified sterilized microspheres. The optimum synthetic conditions were obtained by elemental analysis. The microspheres with excellent bactericidal properties were screened by testing the minimal inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the tested bacteria. The main contents are as follows: 1. Chitosan was crosslinked with epichlorohydrin. Under the single factor condition, the cross-linked microspheres were used as the parent and the bactericidal functional ligands were introduced. A new type of modified sterilized microspheres was synthesized. The nitrogen content of the microspheres was obtained by elemental analysis. The conversion rate of four new modified microspheres was calculated and the optimum reaction solvent was judged according to the conversion rate of each kind of microspheres. Under the optimum reaction temperature and mass ratio, the conversion rates of APC-DMTC and CCC were 39.4% and 42.9%, respectively. The structure of the modified microspheres was characterized by IR spectra and the synthetic route of the modified microspheres was deduced. The thermal stability of microspheres was investigated by thermogravimetry. Determination of minimal inhibitory concentration and minimal bactericidal concentration of Staphylococcus aureus. The sterilizing effect of modified microspheres was investigated. The results showed that ABTC and CCC had the best bactericidal efficacy. In order to further understand the properties of sterilizing microspheres, the effect of Ag / Cu _ 2 on the sterilizing effect of microspheres was discussed. The results showed that ABTC and CCC microspheres could still maintain good bactericidal properties. (3) the activities of extracellular DNA and RNA-TTC- dehydrogenase were determined by ABTC and CCC as the representative of sterilizing microspheres. The sterilizing mechanism of microspheres was discussed, and the reusability of metal adsorption and sterilizing of microspheres was tested. The adsorption rate of the two microspheres could still be kept above 95% after 5 times of repeated use of metal ions. As an efficient bactericide, it can be reused twice and characterized by thermogravimetric analysis. The changes of thermal stability of microspheres were investigated. 4. The microbe containing drinking water was treated with ABTC and CCC modified sterilizing microspheres at normal flow rate. The results showed that ABTC and CCC modified microspheres had good bactericidal effect.
【学位授予单位】：浙江工商大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ314.1;R123.6

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