水体中大肠杆菌富集新方法的建立

发布时间：2018-04-28 22:00

本文选题：大肠杆菌 + 富集　；参考：《大连理工大学》2016年硕士论文

【摘要】：关注共享水的安全问题,是一个十分重要的社会问题。由于大肠杆菌感染剂量很低,并且是许多食源性和水源性胃肠炎的发病源头,因此对于大肠杆菌的检测十分重要。为了能够准确检测水中的大肠杆菌,人们一直致力于发展一些具有生物特异性的方法。而多种技术的开发,已被证明难以实现所有相关类型病毒的检测。同时少量采样和局部采样,对实际的生活和生产中的大量水样起不到有效的检测。因而大量地,快速地富集水样对于检测就成为一个关键性的手段。本文讨论了一些常用的富集手段,并且综合前人的经验和努力,致力于发展一种新的手段和方法来提高细菌的富集效率,缩短富集的时间,为传统的细菌培养技术和新型的生物分子监测技术提供支持,提高肠道病菌的检测效率和准确性。本论文当中采用两步富集方式对水体中的大肠杆菌0157：H7进行富集回收和检测。一步富集方式即超滤,使用聚丙烯膜对0157：H7进行富集回收,并且在超滤过程中采取反冲洗方式,提高了一步富集的回收效率,富集效率最高可达67.21%；二步富集方式中采用磁性包被粒子对0157：H7进行回收。包被物质均采用无毒,并且生物相容性好的一些物质,合成了氨基磁珠,羧基磁珠,和壳聚糖包被磁珠,对其磁性,XRD,红外等性质作了表征,并对其等电点进行了测定。比较了三种磁珠不同pH值,不同磁珠量,不同吸附时间下的吸附效果。发现氨基磁珠磁珠量在2.5ml时,对大肠杆菌的吸附能力可以达到百分之百,提高了对大肠杆菌的二步富集效率。通过两步富集手段,将水体的体积浓缩至可以测定的范围,浓缩倍数达到500倍。降低了由大体积水样的局部取样造成的测定结果不准确的概率,为细菌检测提供了保障。
[Abstract]:It is a very important social problem to pay attention to the safety of shared water. The detection of Escherichia coli is very important because of the low dose of Escherichia coli and the fact that it is the source of many gastroenteritis caused by food and water. In order to detect E. coli in water accurately, some biological specific methods have been developed. However, the development of various technologies has proved difficult to detect all the related viruses. At the same time, a small amount of sampling and local sampling can not effectively detect a large number of water samples in real life and production. Therefore, a large number of rapid enrichment of water samples for detection becomes a key means. In this paper, some common enrichment methods are discussed, and based on previous experiences and efforts, a new method is developed to improve the efficiency of bacteria enrichment and shorten the time of enrichment. It provides support for traditional bacterial culture technology and new biomolecular monitoring technology to improve the detection efficiency and accuracy of intestinal bacteria. In this paper, two-step enrichment method was used for the recovery and detection of Escherichia coli 0157:H7 in water. In the process of one step enrichment, ultrafiltration is used to enrich and recover 0157:H7 with polypropylene membrane, and backwashing is adopted in the process of ultrafiltration, which improves the recovery efficiency of one step enrichment. The highest enrichment efficiency is 67.21, and the magnetic encapsulated particles are used to recover 0157:H7 in the two-step enrichment. Aminomagnetic beads, carboxyl beads and chitosan coated beads were synthesized by using nontoxic and biocompatible materials. The magnetic properties of the beads were characterized by XRDand IR, and their isoelectric points were determined. The adsorption effects of three kinds of magnetic beads under different pH value, different amount of magnetic beads and different adsorption time were compared. It was found that when the amount of magnetic beads of amino magnetic beads was 2.5ml, the adsorption ability of Escherichia coli could reach 100%, which improved the efficiency of two-step enrichment of Escherichia coli. By means of two-step enrichment, the volume of water was condensed to the measurable range, and the concentration multiple reached 500 times. The probability of inaccuracy caused by local sampling of large water samples is reduced, which provides a guarantee for bacterial detection.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R123.1

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