不同制法纳米银的抗菌活性及其应用研究

发布时间：2018-01-04 16:39

  本文关键词：不同制法纳米银的抗菌活性及其应用研究　出处：《中北大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 纳米银 制备 抗菌活性 抗菌机理 保鲜应用

【摘要】：纳米银材料性能稳定,在物理化学等诸多方面具有比普通银更优异的性能,已广泛应用于化工、医疗、生物、电子等领域,近年来纳米银的制备尤其是绿色制备及抗菌机理受到国内外广泛关注。本论文通过研究纳米银的化学与生物制备、抗真菌活性、抗菌机理以及纳米银作为保鲜剂在水果中的应用,为纳米银作为真菌源抗菌剂提供理论基础和应用技术支撑。主要研究结果如下:(1)采用化学还原法制备纳米银,以7种植物病原真菌为代表,研究化学纳米银对不同病原真菌的抗菌效果。研究发现,纳米银为类球形,粒径范围5-30 nm。纳米银对病原真菌有较强的抑制效果,10μg/mL的纳米银对病原菌的抑菌率达65%以上。纳米银对小麦赤霉菌和苹果腐烂菌的抑制效果较好;其次是番茄枯萎菌和菜豆菌核;对菜豆壳菌、西瓜枯萎菌和棉花枯萎菌的抑制效果较差。(2)以小麦赤霉菌为代表菌株,研究纳米银对菌体细胞内3种保护酶和对细胞渗透调节物质的影响,初步探讨纳米银的抗真菌机理。结果表明,随着纳米银处理时间(2h、4 h、6 h、8 h、10 h)的增长,3种酶的活性均出现先增加后降低的变化。纳米银使得菌体内丙二醛含量增加,可溶性蛋白和可溶性糖含量降低。纳米银破坏了病原真菌体内细胞膜系统的完整性,这可能是纳米银抑制病原真菌生长的机理之一。(3)利用乌龙茶浸取液作为还原剂和稳定剂合成纳米银,分析不同反应条件对合成纳米银的影响,进一步研究纳米银对不同病原真菌的抗菌活性。实验发现,乌龙茶浸取液制备纳米银的最佳条件为:AgNO3含量1:50,反应温度80℃,反应时间60 min,茶水配比1:40。纳米银为类球形,高度结晶性,粒径范围10-30 nm。茶叶纳米银与化学纳米银的抑菌活性相比,茶叶纳米银的抑菌活性较好,更具有开发为真菌源杀菌剂的应用前景。(4)以圣女果为研究对象,研究纳米银对水果保鲜品质的影响。研究表明,经纳米银涂膜处理后的圣女果,均能有效降低水果的失重率、TSS含量和Vc含量,较好地抑制圣女果腐烂度、维持色泽、改善气味。茶叶纳米银保鲜效果优于化学纳米银,茶叶纳米银有望开发为真菌源杀菌剂应用于保鲜方面。
[Abstract]:Nanocrystalline silver has been widely used in chemical, medical, biological, electronic and other fields because of its stable properties and excellent physical and chemical properties. In recent years, the preparation of nano-silver, especially the green preparation and antibacterial mechanism, has been widely concerned at home and abroad. Antibacterial mechanism and application of nano-silver as preservative in fruit. The main results are as follows: 1) Nano-silver was prepared by chemical reduction method, represented by seven plant pathogenic fungi. The antimicrobial effect of silver nanoparticles on different pathogenic fungi was studied. It was found that silver nanoparticles were spherical in size and 5-30 nm in diameter. Silver nanoparticles had a strong inhibitory effect on pathogenic fungi. The inhibition rate of 10 渭 g / mL nano-silver against pathogenic bacteria was more than 65%. The inhibition effect of nano-silver on wheat gibberellosis and apple rot bacteria was better. Secondly, tomato wilt and bean sclerotia; The effect of silver nanoparticles on three kinds of protective enzymes and osmotic regulatory substances in bacterial cells was studied with wheat gibberella as the representative strain. The antifungal mechanism of silver nanoparticles was preliminarily discussed. The results showed that the antifungal mechanism of silver nanoparticles increased with the treatment time of 2 h ~ 4 h ~ 6 h ~ 6 h ~ 8 h ~ (10 h). The activity of the three enzymes increased first and then decreased, and the content of malondialdehyde increased. The content of soluble protein and soluble sugar decreased. Silver nanoparticles destroyed the integrity of cell membrane system of pathogenic fungi. This may be one of the mechanisms of silver nanoparticles inhibiting the growth of pathogenic fungi. (3) Nano-silver was synthesized by using the extract of Oolong tea as reducing agent and stabilizer, and the effect of different reaction conditions on the synthesis of nano-silver was analyzed. The antimicrobial activity of silver nanoparticles against different pathogenic fungi was further studied. It was found that the optimum conditions for the preparation of silver nanoparticles from the extract of Oolong tea were as follows: 1: Agno _ 3 content 1: 50, reaction temperature 80 鈩，

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