本文關(guān)鍵詞：不同制法納米銀的抗菌活性及其應(yīng)用研究　出處：《中北大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： 納米銀 制備 抗菌活性 抗菌機(jī)理 保鮮應(yīng)用

【摘要】：納米銀材料性能穩(wěn)定,在物理化學(xué)等諸多方面具有比普通銀更優(yōu)異的性能,已廣泛應(yīng)用于化工、醫(yī)療、生物、電子等領(lǐng)域,近年來(lái)納米銀的制備尤其是綠色制備及抗菌機(jī)理受到國(guó)內(nèi)外廣泛關(guān)注。本論文通過(guò)研究納米銀的化學(xué)與生物制備、抗真菌活性、抗菌機(jī)理以及納米銀作為保鮮劑在水果中的應(yīng)用,為納米銀作為真菌源抗菌劑提供理論基礎(chǔ)和應(yīng)用技術(shù)支撐。主要研究結(jié)果如下:(1)采用化學(xué)還原法制備納米銀,以7種植物病原真菌為代表,研究化學(xué)納米銀對(duì)不同病原真菌的抗菌效果。研究發(fā)現(xiàn),納米銀為類(lèi)球形,粒徑范圍5-30 nm。納米銀對(duì)病原真菌有較強(qiáng)的抑制效果,10μg/mL的納米銀對(duì)病原菌的抑菌率達(dá)65%以上。納米銀對(duì)小麥赤霉菌和蘋(píng)果腐爛菌的抑制效果較好;其次是番茄枯萎菌和菜豆菌核;對(duì)菜豆殼菌、西瓜枯萎菌和棉花枯萎菌的抑制效果較差。(2)以小麥赤霉菌為代表菌株,研究納米銀對(duì)菌體細(xì)胞內(nèi)3種保護(hù)酶和對(duì)細(xì)胞滲透調(diào)節(jié)物質(zhì)的影響,初步探討納米銀的抗真菌機(jī)理。結(jié)果表明,隨著納米銀處理時(shí)間(2h、4 h、6 h、8 h、10 h)的增長(zhǎng),3種酶的活性均出現(xiàn)先增加后降低的變化。納米銀使得菌體內(nèi)丙二醛含量增加,可溶性蛋白和可溶性糖含量降低。納米銀破壞了病原真菌體內(nèi)細(xì)胞膜系統(tǒng)的完整性,這可能是納米銀抑制病原真菌生長(zhǎng)的機(jī)理之一。(3)利用烏龍茶浸取液作為還原劑和穩(wěn)定劑合成納米銀,分析不同反應(yīng)條件對(duì)合成納米銀的影響,進(jìn)一步研究納米銀對(duì)不同病原真菌的抗菌活性。實(shí)驗(yàn)發(fā)現(xiàn),烏龍茶浸取液制備納米銀的最佳條件為:AgNO3含量1:50,反應(yīng)溫度80℃,反應(yīng)時(shí)間60 min,茶水配比1:40。納米銀為類(lèi)球形,高度結(jié)晶性,粒徑范圍10-30 nm。茶葉納米銀與化學(xué)納米銀的抑菌活性相比,茶葉納米銀的抑菌活性較好,更具有開(kāi)發(fā)為真菌源殺菌劑的應(yīng)用前景。(4)以圣女果為研究對(duì)象,研究納米銀對(duì)水果保鮮品質(zhì)的影響。研究表明,經(jīng)納米銀涂膜處理后的圣女果,均能有效降低水果的失重率、TSS含量和Vc含量,較好地抑制圣女果腐爛度、維持色澤、改善氣味。茶葉納米銀保鮮效果優(yōu)于化學(xué)納米銀,茶葉納米銀有望開(kāi)發(fā)為真菌源殺菌劑應(yīng)用于保鮮方面。
[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，

本文編號(hào)：1379236