右旋酪氨酸及糖苷水解酶缓解膜系统中膜污染的研究

发布时间：2017-12-27 14:13

本文关键词：右旋酪氨酸及糖苷水解酶缓解膜系统中膜污染的研究　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：膜污染是膜分离技术中存在的一个瓶颈问题,限制了膜技术的进一步发展。因此,开发缓解膜污染的新技术方法对膜技术至关重要。本研究选用生物自身分泌的两种物质右旋酪氨酸和糖苷水解酶PslG,探究它们对膜污染的抑制作用并解析作用机理。采用一种简单温和的两步法将右旋酪氨酸修饰到聚醚砜(PES)膜表面,通过增加膜表面亲水性及抗菌性,进而缓解膜生物污染。结果显示,右旋酪氨酸修饰后能够增加膜表面亲水性、降低粗糙度,并且不会对膜的渗透性能产生影响。在牛血清白蛋白(BSA)的过滤实验中,D-tyrosine-PDA/PES膜总的统一膜污染指数(UMFI)是0.00162,仅为PDA/PES膜UMFI的一半。同时,D-tyrosine-PDA/PES膜的水通量恢复率(FRR)增加至79%,高于原始PES膜的FRR。修饰后,膜表面细菌粘附率由29.2%降到19%,抗粘附性能增加。细菌污染前后,膜的水通量对比图也说明修饰后膜表面抗生物污染性能增加。这种膜表面改性的方法可以同时增强膜的抗粘附及抗菌性能,实现了用生物方法缓解膜污染。本章研究又采用直接投加法,探究糖苷水解酶PslG对膜污染的控制作用。细菌粘附实验结果表明,在较短时间内,PslG能明显抑制细菌在膜表面粘附,且抑制效果与加入的PslG浓度没有关系。PslG的存在并不会影响细菌表面zeta电位及疏水率。24h的粘附实验显示,投加高浓度的PslG(500、1000nM)才会对细菌粘附产生明显的抑制作用。同时cross-flow过滤实验说明,PslG能够缓解过滤过程中产生的膜生物污染。PslG的存在减少了菌液EPS中胞外多糖的分泌,这也是其抑制细菌粘附、缓解膜生物污染的原因。
[Abstract]:Membrane fouling is a bottleneck problem in membrane separation technology, which restricts the further development of membrane technology. Therefore, the development of new technology to alleviate membrane pollution is very important to membrane technology. In this study, two kinds of dextral tyrosine and glucoside hydrolase PslG, which were secreted by biological self - secreting, were used to explore their inhibitory effects on membrane pollution and to analyze the mechanism. A simple mild two step method was applied to modify the dextran tyrosine onto the surface of polyethersulfone (PES) membrane, which increased membrane surface hydrophilicity and antibacterial activity, and further alleviated membrane biofouling. The results show that the modification of Dextre tyrosine can increase the hydrophilicity of the membrane surface, reduce the roughness, and do not affect the permeability of the membrane. In the filtration experiment of bovine serum albumin (BSA), the total uniform membrane fouling index (UMFI) of the D-tyrosine-PDA/PES membrane was 0.00162, only half of the UMFI of the PDA/PES membrane. At the same time, the recovery rate of water flux (FRR) of the D-tyrosine-PDA/PES film increased to 79%, which was higher than that of the original PES film FRR. After modification, the bacterial adhesion rate of the membrane surface decreased from 29.2% to 19%, and the adhesion resistance increased. Before and after the bacterial contamination, the water flux contrast diagram of the membrane also showed that the surface resistance of the modified membrane was increased. The membrane surface modification method can enhance the anti adhesion and antibacterial properties of the membrane at the same time, and the membrane fouling can be alleviated by biological method. In this chapter, the direct addition method is used to explore the control effect of glycoside hydrolase PslG on membrane pollution. The results of bacterial adhesion test showed that PslG could obviously inhibit the adhesion of bacteria on the membrane surface in a short time, and the inhibition effect was not related to the concentration of PslG. The presence of PslG does not affect the surface zeta potential and hydrophobicity of the bacteria. The adhesion test of 24h showed that high concentration of PslG (500, 1000nM) could inhibit the adhesion of bacteria. At the same time, the cross-flow filtration experiment showed that PslG could alleviate the biofilm pollution produced during the filtration process. The presence of PslG reduces the secretion of extracellular polysaccharide in the bacterial liquid EPS, which is also the reason for its inhibition of bacterial adhesion and biofilm contamination.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X505

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