本文選題：納米銀 + 抑菌��； 參考：《蘇州大學(xué)》2015年碩士論文

【摘要】：納米銀是以納米技術(shù)為基礎(chǔ)研制而成的新型抗菌產(chǎn)品,比Ag+具有更穩(wěn)定的物理化學(xué)特性,由于小尺寸效應(yīng)、量子效應(yīng)和具有極大的比表面積,因而具有傳統(tǒng)無(wú)機(jī)抗菌劑無(wú)法比擬的抗菌效果,使銀所具有的強(qiáng)效消毒殺菌功能更是有了質(zhì)的飛躍,且效力持久、安全性高,不易產(chǎn)生耐藥性。生物合成納米銀,具有安全性高、綠色環(huán)保、成本低廉等特點(diǎn),在綠色合成納米銀領(lǐng)域有著廣闊的應(yīng)用前景。本文分別采用化學(xué)方法和生物方法合成納米銀,研究其抑菌活性,并探討了抑菌機(jī)理�；瘜W(xué)合成納米銀利用抗壞血酸作為還原劑,通過(guò)二氧化硅的包裹,成功的得到平均粒徑為92.9 nm的核殼型銀-二氧化硅納米粒(Ag-Si O2 NPs)。該納米粒子可抑制人類病原菌白色念珠菌以及植物病原菌香石竹鐮刀菌的生長(zhǎng)。通過(guò)常量肉湯稀釋法,確定了Ag-Si O2 NPs對(duì)白色念珠菌的IC50為2μg/ml。通過(guò)杯碟法測(cè)定對(duì)植物病原菌香石竹鐮刀菌的抑制,最低抑菌濃度(MIC)為4μg/ml。本實(shí)驗(yàn)首次利用紅豆杉細(xì)胞的提取液作為原料,綠色合成了粒徑為3-5 nm均一度良好的納米銀,p H=10,反應(yīng)時(shí)間60 min為反應(yīng)最佳條件。抑菌實(shí)驗(yàn)表明,用紅豆杉合成的納米銀對(duì)人類病原菌有較強(qiáng)的抑制作用,尤其是革蘭氏陽(yáng)性菌,對(duì)于金黃色葡萄球菌(Staphylococcus aureus)和枯草芽孢桿菌(Bacillus subtilis)的最低抑菌濃度低至1μg/ml;對(duì)于革蘭氏陰性菌大腸埃希菌(Escherichia coil)的最低抑菌濃度為8μg/ml,對(duì)乙型副傷寒沙門菌(Salmonella paratyphi B)的最低抑菌濃度為4μg/ml。最后我們探討了納米銀對(duì)人類病原菌白色念珠菌(Candida albicans)、植物病原菌香石竹鐮刀菌(Fusarium oxysporum)的抑菌機(jī)制,為納米銀抑菌應(yīng)用供理論依據(jù)。研究結(jié)果表明:(1)Ag-Si O2 NPs獨(dú)特的核殼型結(jié)構(gòu)可以緩慢釋放銀離子,當(dāng)引入半胱氨酸螯合培養(yǎng)基中釋放的Ag+后,依然有較強(qiáng)的抑菌能力,說(shuō)明Ag-Si O2 NPs的抑菌作用是Ag+和納米級(jí)別粒子共同作用的結(jié)果。(2)進(jìn)一步研究了Ag-Si O2 NPs對(duì)成膜白色念珠菌的抑制能力。結(jié)果表明,Ag-Si O2 NPs不僅對(duì)生物膜形成初期有抑制作用,對(duì)成熟期的菌膜仍然有良好的抑菌效果,說(shuō)明Ag-Si O2 NPs可以不受胞外基質(zhì)的阻礙,抑制生物膜的形成和發(fā)展。(3)在Ag-Si O2 NPs作用下,鐮刀菌菌絲體的生長(zhǎng)呈現(xiàn)異常狀態(tài),且無(wú)法正常分生孢子,說(shuō)明Ag-Si O2納米�？赡軙�(huì)促使鐮刀菌畸變,使其無(wú)法正常生長(zhǎng),繁殖,失去侵染植物能力。(4)通過(guò)流式細(xì)胞儀檢測(cè)發(fā)現(xiàn),抑菌過(guò)程中有活性氧(ROS)的產(chǎn)生,同時(shí)我們測(cè)得線粒體膜電位△Ψm明顯下降,呈一定的時(shí)間劑量依賴關(guān)系。Ag-Si O2 NPs處理鐮刀菌后,細(xì)胞內(nèi)抗氧化酶如過(guò)氧化氫酶、總超氧化物歧化酶、過(guò)氧化物酶的活力呈現(xiàn)上升以后再下降的趨勢(shì),結(jié)果說(shuō)明:納米銀可能通過(guò)刺激菌體產(chǎn)生ROS,導(dǎo)致菌體氧化還原態(tài)勢(shì)顯著變化,誘導(dǎo)菌體線粒體膜電位△Ψm下降,從而造成菌體的死亡。本論文探討了納米銀合成的化學(xué)方法和生物方法,我們首次報(bào)道了利用紅豆杉細(xì)胞綠色合成納米銀的方法。通過(guò)研究納米銀的抑菌機(jī)制,揭示了納米銀誘導(dǎo)菌體活性氧產(chǎn)生,以及對(duì)菌體生物膜形成的破壞、孢子萌發(fā)和菌體生長(zhǎng)的抑制,為納米銀抗菌研究提供了新型合成方法和較深入的抗菌機(jī)制。
[Abstract]:Nano silver is a new type of antibacterial product developed on the basis of nanotechnology. It has more stable physical and chemical properties than Ag+. Because of its small size effect, quantum effect and great specific surface area, it has the antiseptic effect incomparable with the traditional inorganic antiseptic, and makes the sterilizing and sterilizing function of silver more qualitative. The biosynthesis of nano silver, which has the characteristics of high safety, green environmental protection, low cost and so on, has a broad application prospect in the field of green synthesis of nano silver. In this paper, the antibacterial activity of nano silver was combined with chemical methods and biological methods, and the antibacterial mechanism was studied and the antibacterial mechanism was discussed. The chemical synthesis of silver nanoparticles using ascorbic acid as a reducing agent, through the inclusion of silica, has successfully obtained a nucleated shell type silver silica nanoparticles (Ag-Si O2 NPs) with an average particle size of 92.9 nm. This nanoparticle can inhibit the growth of Candida albicans and plant pathogenic fungus Fusarium oxycariensis. Ag-Si O2 NPs was used to determine the IC50 of Candida albicans to 2 mu g/ml. by cup disc method. The minimum inhibitory concentration (MIC) was 4 u g/ml.. The extraction solution of Taxus cells was used for the first time as raw material. The green synthesis of nano silver with a good uniformity of diameter of 3-5 nm, P H=10, reaction Time 60 min was the best reaction condition. Bacteriostasis experiment showed that nanoscale silver synthesized by Taxus had strong inhibitory effect on human pathogenic bacteria, especially Gram-positive bacteria, the minimum inhibitory concentration for Staphylococcus aureus (Staphylococcus aureus) and Bacillus subtilis (Bacillus subtilis) was low to 1 u g/ml; The minimum inhibitory concentration of Escherichia coli (Escherichia coil) was 8 u g/ml, and the minimum inhibitory concentration for Salmonella paratyphi B was 4 u g/ml.. Finally, we explored the Bacteriostasis of nanoscale silver to human pathogen Candida albicans (Candida albicans), and the pathogen of plant pathogen (Fusarium oxysporum). The mechanism is the theoretical basis for the antibacterial application of nano silver. The results show that: (1) the unique nuclear shell structure of Ag-Si O2 NPs can release silver ions slowly. After introducing the Ag+ released in the cysteine chelate medium, it still has strong bacteriostasis. It shows that the Bacteriostasis of Ag-Si O2 NPs is the joint of Ag+ and nanoscale particles. Fruit. (2) further study the inhibition ability of Ag-Si O2 NPs on the membrane of Candida albicans. The results show that Ag-Si O2 NPs not only has inhibitory effect on the early stage of biofilm formation, but also has good bacteriostasis effect on the membrane of mature period, indicating that Ag-Si O2 NPs can not be hindered by extracellular matrix and inhibits the formation and development of biofilm. (3) Ag-Si O. Under the action of 2 NPs, the growth of Fusarium mycelium is abnormal and can not be normal conidia. It shows that Ag-Si O2 nanoparticles may induce the aberration of Fusarium, so that it can not grow normally, reproduce and lose the ability to infect plants. (4) it was found by flow cytometry that the production of active oxygen (ROS) in the process of bacteriostasis, and we have measured it. The mitochondrial membrane potential delta m decreased obviously, and the activity of intracellular antioxidant enzymes such as catalase, total superoxide dismutase and peroxidase decreased after a certain time dose dependence of.Ag-Si O2 NPs, and the results showed that nano silver may produce ROS by stimulating the mycelium and lead to the mycelium. In this paper, the chemical methods and biological methods for the synthesis of nano silver were discussed. We first reported the method of using the green synthesis of silver in the Taxus cells. The antibacterial mechanism of nano silver was studied and the nano silver lure was revealed. The production of the active oxygen of the mycelium, the destruction of the biofilm formation, the germination of the spores and the inhibition of the growth of the mycelium, provide a new synthesis method and a more thorough antibacterial mechanism for the antibacterial study of nano silver.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.1

【引證文獻(xiàn)】

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本文編號(hào)：1931852