下载文档原格式
毕业论文外文翻译-壳聚糖-茶多酚纳米颗粒的合成和性质及细胞毒性的研究Synthesis and Characterization of Chitosan-Tea Polyphenol Nanoparticles and Their Cytotoxicity StudyAbstractIn this study, chitosan-tea polyphenol nanoparticles were synthesized using a simple and green method. The physical and chemical properties of the nanoparticles were characterized by various techniques including dynamic light scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. The cytotoxicity of the nanoparticles was evaluated using MTT assay and cell morphological observation. The results showed that the synthesized nanoparticles had a diameter of 183.6 nm, a positive surface charge of 27.54 mV, and a polydispersity index of 0.22. The nanoparticles exhibited good biocompatibility with cells and low cytotoxicity, indicating their potential application in drug delivery.Keywords: chitosan, tea polyphenol, nanoparticles, cytotoxicity, drug deliveryIntroductionNanoparticles have been extensively studied in the field of drug delivery due to their unique properties such as high surface area, high reactivity, and enhanced permeation and retention effect. Among various materials, chitosan has attracted great attention as a drug delivery carrier due to its biocompatibility, biodegradability, and low toxicity (1). However, chitosan nanoparticles often suffer from low stability and poor solubility, which limit their application in drug delivery. To overcome these limitations, various methods have been developed to improve the stability and solubility of chitosan nanoparticles, such as crosslinking, coating, and blending with other materials (2).Tea polyphenols are natural plant extracts with various biological activities such as antioxidation, anticancer, and anti-inflammatory effects (3). Therefore, tea polyphenols have been widely used as functional food ingredients and nutraceuticals. In addition, tea polyphenols have also been investigated as potential anticancer agents due to their ability to induce apoptosis and inhibit cell proliferation (4). However, tea polyphenols suffer from low bioavailability and poor stability, which limit their therapeutic efficacy (5).To improve the stability and solubility of chitosan nanoparticles and enhance the therapeutic efficacy of tea polyphenols, we synthesized chitosan-tea polyphenol nanoparticles using a simple and green method. The physical and chemical properties of the nanoparticles were characterized, and the cytotoxicity of the nanoparticles was evaluated.Materials and MethodsMaterialsChitosan (degree of deacetylation > 85%, molecular weight 300,000-400,000 g/mol) was purchased from Sigma-Aldrich (USA). Tea polyphenols were extracted from green tea leaves and purified using ethanol precipitation according to a previous method (6). Dulbecco's modified eagle medium (DMEM), fetal bovine serum (FBS), and penicillin/streptomycin solution were obtained from Gibco (USA). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and dimethyl sulfoxide (DMSO) were purchased from Sigma-Aldrich (USA). All reagents were of analytical grade and used without further purification.Synthesis of Chitosan-Tea Polyphenol NanoparticlesChitosan-tea polyphenol nanoparticles were prepared using a simple and green method. Briefly, chitosan (50 mg) was dissolved in 5 ml of acetic acid (1%, v/v), and tea polyphenol (5 mg) was dissolved in 5 ml of distilled water. The tea polyphenol solution was added dropwise into the chitosan solution under magnetic stirring at room temperature. The mixture was stirred for another 30 min to obtain a homogeneous solution. The solution was then added dropwise to 20 ml of 0.1 M sodium hydroxide solution under magnetic stirring to induce nanoparticle formation. The mixture was stirred for 60 min and then centrifuged at 10,000 rpm for 10 min to remove unreacted materials. The nanoparticles were washed three times with distilled water and freeze-dried for further use.Characterization of Chitosan-Tea Polyphenol NanoparticlesThe physical and chemical properties of chitosan-tea polyphenol nanoparticles were characterized by various techniques. The nanoparticle size and zeta potential were measured using a dynamic light scattering instrument (Malvern, UK). The particle morphology was observed using a transmission electron microscope (TEM, JEOL, Japan) after negative staining with uranyl acetate. The chemical structure of the nanoparticles was analyzed by Fourier transform infrared spectroscopy (FTIR, PerkinElmer, USA) using KBr pellets.Cytotoxicity StudyThe cytotoxicity of chitosan-tea polyphenol nanoparticles was evaluated using MTT assay and cell morphological observation. Human gastric cancer cells (SGC-7901) were seeded in a 96-well plate at a density of 5 × 103 cells per well in DMEM supplemented with 10% FBS and 1% penicillin/streptomycin solution. After 24 h, the cells were treated with different concentrations of chitosan-tea polyphenol nanoparticles (0, 12.5, 25, 50, 100, and 200 μg/ml) for 24 h. Then, the MTT solution (5 mg/ml) was added to each well and incubated for another 4 h. The supernatant was discarded, and DMSO was added to dissolve the formazan crystals. The absorbance was measured at 490 nm using a microplate reader (BioTek, USA). Cell viability was calculated as a percentage of the control group.For cell morphological observation, the cells were treated with chitosan-tea polyphenol nanoparticles (50 μg/ml) for 24 h and then observed under an inverted microscope (Olympus, Japan).Results and DiscussionsCharacterization of Chitosan-Tea Polyphenol NanoparticlesChitosan-tea polyphenol nanoparticles were synthesized using a simple and green method, and the physical and chemical properties of the nanoparticles were characterized by various techniques. As shown in Figure 1A and B, the nanoparticles had a diameter of 183.6 nm and a positive surface charge of 27.54 mV, indicating good stability and low aggregation. The nanoparticles exhibited a narrow size distribution with a polydispersity index of 0.22, indicating good homogeneity. The TEM image of the nanoparticles showed a spherical shape with a smooth surface, and the size observed by TEM was consistent with the DLS measurement (Figure 1C). FTIR spectroscopy was used to investigate the chemical structure of the nanoparticles. The characteristic absorption peaks of chitosan at 1658 cm-1 (amide I) and 1569 cm-1 (amide II) were observed in the spectrum of chitosan-tea polyphenol nanoparticles, indicating the successful formation of nanoparticles (Figure 1D).Cytotoxicity StudyThe cytotoxicity of chitosan-tea polyphenol nanoparticles was evaluated using MTT assay and cell morphological observation. As shown in Figure 2A, the cell viability of SGC-7901 cells treated with chitosan-tea polyphenol nanoparticles wasabove 90% at concentrations up to 200 μg/ml, indicating good biocompatibility with cells and low cytotoxicity. The morphological observation of cells treated with chitosan-tea polyphenol nanoparticles (50 μg/ml) showed no obvious changes compared with the control group (Figure 2B).ConclusionIn this study, we successfully synthesized chitosan-tea polyphenol nanoparticles using a simple and green method. The nanoparticles had a diameter of 183.6 nm, a positive surface charge of 27.54 mV, and a polydispersity index of 0.22, indicating good stability and low aggregation. The nanoparticles exhibited good biocompatibility with cells and low cytotoxicity, indicating their potential application in drug delivery. Further studies are needed to investigate the in vivo efficacy and safety of these nanoparticles.Figure 1 Characterization of chitosan-tea polyphenol nanoparticles. (A) Size distribution of nanoparticles measured by dynamic light scattering; (B) Zeta potential of nanoparticles; (C) Transmission electron microscopy image of nanoparticles; (D) Fourier transform infrared spectroscopy spectra of chitosan and chitosan-tea polyphenol nanoparticles.Figure 2 Cytotoxicity evaluation of chitosan-tea polyphenol nanoparticles. (A) MTT assay of SGC-7901 cells treated with different concentrations of nanoparticles (n = 3, *p < 0.05 compared with control); (B) Morphological observation of SGC-7901 cells treated with chitosan-tea polyphenol nanoparticles (50 μg/ml) and control group.AcknowledgmentsThis work was supported by the National Natural Science Foundation of China (No. 81673508).References1. Qi L, Xu Z, Jiang X, Hu C, Zou X, Preparation and antibacterial activity of chitosan nanoparticles. Carbohydr Res. 2004;339:2693-2700.2. Chen M-C, Mi F-L, Liao Z-X, Hsiao C-W, Sonaje K, Chung M-F, et al., Recent advances in chitosan-based nanoparticles for oral delivery of macromolecules.Adv Drug Deliv Rev. 2013;65:865-879.3. Wang D, Wang H, Guo Y, Ning W, Katirai F, Zhou Q, et al., Antioxidant properties and neuroprotective capacity of naturally occurring polyphenols in Parkinson's disease.Antioxidants (Basel). 2019;8:420.4. Siddiqui IA, Adhami VM, Ahmad N, Mukhtar H, Nanochemoprevention: sustained release of bioactive food components for cancer prevention.Nutr Cancer. 2010;62:883-890.5. Floegel A, Kim D-O, Chung S-J, Koo SI, Chun O-K, Comparison ofABTS/DPPH assays to measure antioxidant capacity in popular antioxidant-rich US foods.J Food Compos Anal. 2011;24:1043-1048.6. Zhang L, Yang X, Lv Y, Wang P, Gao Y, Hu K, et al., Optimizing the ultrasonic-assisted extraction of tea polyphenols from green tea using response surface methodology.J Food Sci. 2012;77:C1205-C1210.。
第32卷第6期2012年12月 上饶师范学院学报J OURNAL O F SHANGR AO NOR MAL UNIVERSITY Vol 32,No 6Dec 2012收稿日期:2012-03-30基金项目:上饶师范学院2011年教学改革研究项目(201105)。
作者简介:叶利民(1975-),男,江西进贤人,硕士,讲师,主要从事微生物学教学与研究。
壳聚糖的抑菌效果研究叶利民,刘 翔(上饶师范学院,江西上饶334001)摘要:比较了苯甲酸和不同浓度壳聚糖对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、黑曲霉菌、苏云金芽孢杆菌等的抑菌效果。
研究结果表明,壳聚糖对以上五种菌均具有一定的抑菌效果,且抑菌效果好于苯甲酸。
壳聚糖对金黄色葡萄球菌和苏云金杆菌的最低抑菌浓度为0.125%,对大肠杆菌的最低抑菌浓度为0.25%,对枯草芽孢杆菌的最低抑菌浓度为0.5%,对黑曲霉的最低抑菌浓度为1.0%。
说明,金黄色葡萄球菌和苏云金杆菌对壳聚糖较敏感,黑曲霉对壳聚糖不太敏感。
关键词:壳聚糖;最低抑菌浓度;抑菌活性中图分类号:Q93.334 文献标识码:A 文章编号:1004-2237(2012)06-0085-04DOI:10.3969/j.issn.1004-2237.2012.06.018目前,由于价格低廉的优势,国内食品工业中使用最多的防腐剂仍然是苯甲酸钠和苯甲酸,但是苯甲酸类存在叠加中毒现象,在使用上有争议,而且在一些国家的进口食品中受到限制[1]。
随着人们生活水平的提高,广谱、高效、安全抗菌剂的开发应用受到了人们的广泛关注[2]。
壳聚糖(chitosan)是甲壳素(chitin)的一种重要衍生物[3],壳聚糖具有生物相容性、抗菌、环境友好和提取方便等优点,已在许多领域得到了广泛应用,包括废水处理、层析、抗菌材料、生物降解膜、药剂载体[4]。
目前,有关壳聚糖抗菌的研究较多,但大多局限在对植物病原菌[5-8]、金黄色葡萄球菌[9-11]和大肠杆菌[12]的研究。
壳聚糖对几种植物病原真菌的作用
于汉寿;张益明
【期刊名称】《天然产物研究与开发》
【年(卷),期】1999(011)005
【摘要】在马铃薯区区糖琼脂（ＰＤＡ）上测定了酸溶性壳聚糖（Ｓ－１）和２种水溶性壳聚糖（Ｓ－Ⅱ和Ｓ－Ⅲ）对１５种植物病原真菌的作用，结果表明，三种壳聚糖对供试的１５种植物病原真菌均有一定程度的抑制作用，抑制强度因壳聚糖的理化性质以及不同的病原真菌而较大差异。
水溶性壳聚糖Ｓ－Ⅱ可明显抑制水稻恶苗病菌分生孢子的萌发。
壳聚糖的抑菌作用机制与其增加菌丝细胞膜的透性有关。
【总页数】1页(P33)
【作者】于汉寿;张益明
【作者单位】江苏丘陵地区镇江农科所;南京农业大学
【正文语种】中文
【中图分类】S143.8
【相关文献】
1.不同分子量壳聚糖对几种植物病原真菌的拮抗作用 [J], 廖春燕;马国瑞;陈美慈;洪文英
2.哈茨木霉Thga1基因敲除突变株对几种植物病原真菌的离体拮抗作用 [J], 刘增亮;李梅;张玉杰;张林;杨晓燕;蒋细良;
3.1株柑橘炭疽病生防放线菌对几种植物病原真菌的抑制作用 [J], 吴思梦;王文君;
刘冰;蒋军喜;
4.1株柑橘炭疽病生防放线菌对几种植物病原真菌的抑制作用 [J], 吴思梦;王文君;刘冰;蒋军喜
5.薄荷精油对几种植物病原真菌的抑制作用研究 [J], 刘琳玉;牛之函;任艳利
因版权原因，仅展示原文概要，查看原文内容请购买。
不同分子量壳聚糖对几种植物病原真菌的拮抗作用廖春燕;马国瑞;陈美慈;洪文英【期刊名称】《浙江农业学报》【年(卷),期】2001(013)003【摘要】@@壳聚糖是甲壳素脱去乙酰基后得到的一种高分子阳离子多聚糖，广泛存在于真菌的细胞壁及虾、蟹等甲壳动物外壳中。
壳聚糖及其衍生物被广泛地应用于医药、农业、食品、化工等领域。
在农业中，它不仅具有果蔬保鲜、种子包衣等用途，而且还可以作为一种安全有效的生物农药被开发应用。
壳聚糖能诱导植物的多种抗病性反应［1～4］，对许多病原菌有较为明显的抑制作用［5～8］。
此外，壳聚糖具有无毒、施用后可被土壤微生物完全降解，不会对土壤微环境造成不利影响等优点［9］。
近年来，关于壳聚糖诱导植物抗病反应的研究得到各国科学家的关注，但有关壳聚糖不同分子量及不同浓度对植物病原真菌抑制作用的影响则未见系统报道。
本文以3种不同分子量的壳聚糖为材料，研究了不同分子量、不同浓度的壳聚糖对几种植物病原真菌的拮抗作用，获得了一些新资料，现整理如下。
【总页数】4页(P172-175)【作者】廖春燕;马国瑞;陈美慈;洪文英【作者单位】浙江大学环境与资源学院,;浙江大学环境与资源学院,;浙江大学生命科学学院,;杭州市蔬菜研究所,【正文语种】中文【中图分类】S481+.1【相关文献】1.白黄笋顶孢霉对几种植物病原真菌的拮抗作用 [J], 何苏琴;金秀琳;王生荣2.哈茨木霉Thga1基因敲除突变株对几种植物病原真菌的离体拮抗作用 [J], 刘增亮;李梅;张玉杰;张林;杨晓燕;蒋细良;3.哈茨木霉Thga1基因敲除突变株对几种植物病原真菌的离体拮抗作用 [J], 刘增亮;李梅;张玉杰;张林;杨晓燕;蒋细良4.细菌P-FS08的鉴定及其对几种植物病原真菌的拮抗作用 [J], 石志琦;胡梁斌;于淑池;徐朗莱;范永坚5.生防菌株NJ-18的鉴定及其对几种植物病原真菌的拮抗作用研究 [J], 章四平;匡静;王建新;陈长军;周明国因版权原因，仅展示原文概要，查看原文内容请购买。
壳聚糖对红掌离体叶片渗透胁迫的缓解效应
从心黎;黄绵佳;杨意伯
【期刊名称】《云南农业科技》
【年(卷),期】2008(000)001
【摘要】研究不同浓度壳聚糖溶液对红掌离体叶片在15%聚乙二醇-6000(PEG-6 000)渗透胁迫条件下生理生化的影响.结果表明,在渗透胁迫下,壳聚糖(CTS)预处理有效地降低了渗透胁迫条件下红掌叶片的电导率和MDA含量,显著增加了脯氨酸含量和SOD活性,0.4%的CTS处理效果最好.
【总页数】2页(P29-30)
【作者】从心黎;黄绵佳;杨意伯
【作者单位】华南热带农业大学园艺学院,海南,儋州,571737;华南热带农业大学园艺学院,海南,儋州,571737;华南热带农业大学园艺学院,海南,儋州,571737
【正文语种】中文
【中图分类】S5
【相关文献】
1.壳聚糖对芒果离体叶片渗透胁迫的缓解效应 [J], 刘晚苟;黄小明;杨秀坚
2.干旱胁迫对红掌离体叶片生理指标的影响 [J], 从心黎;黄绵佳;杨意伯
3.壳聚糖对沿阶草叶片抗渗透胁迫的影响 [J], 刘晚苟;廖锡佳
4.土壤水分胁迫对红富士苹果叶片渗透调节特性的影响 [J], 杨素苗;杜纪壮;李保国;齐国辉;徐国良;秦立者
5.不同品种红掌叶片细胞膜稳定性和渗透调节物质对高温胁迫的响应 [J], 王宏辉;顾俊杰;房伟民;陈发棣;张栋梁
因版权原因，仅展示原文概要，查看原文内容请购买。
壳聚糖对6株植物枯萎病菌的室内抑菌活性测定刘昌燕;金铃;刘颖颖;汪军;黄俊生【期刊名称】《热带生物学报》【年(卷),期】2010(001)002【摘要】以6株植物枯萎病菌为实验材料,测定了不同含量壳聚糖对植物枯萎病菌抑菌活性的影响.结果表明:壳聚糖对6种植物枯萎病菌都有抑制作用,经壳聚糖处理后,植物枯萎病菌的形态出现畸变.在一定含量范围内,随着壳聚糖含量的增加,抑制作用增强,且在壳聚糖的φ=0.4%时,对6种植物枯萎病菌的菌丝生长、产孢量以及孢子萌发的抑制作用均达到最大;但是随着壳聚糖含量的继续增加,其抑制作用反而下降,这可能与高含量时壳聚糖分子之间通过氢键自相聚集造成有效含量的下降有关.【总页数】5页(P125-129)【作者】刘昌燕;金铃;刘颖颖;汪军;黄俊生【作者单位】中国热带农业科学院,环境与植物保护研究所,海南,儋州,571737;海南大学(儋州校区)农学院,海南,儋州,571737;海南大学(儋州校区)农学院,海南,儋州,571737;海南大学(儋州校区)农学院,海南,儋州,571737;中国热带农业科学院,环境与植物保护研究所,海南,儋州,571737;中国热带农业科学院,环境与植物保护研究所,海南,儋州,571737【正文语种】中文【中图分类】S432.4+4【相关文献】1.8种生物杀菌剂对草莓枯萎病菌室内抑菌活性的测定 [J], 吉沐祥;陈宏州;吴祥;姚克兵;王莉莉;陈源;李国平2.三种植物提取物对黄瓜枯萎病菌的离体抑菌活性测定 [J], 赵飞龙;董海龙;仲嘉伟;张勇智;曹挥;刘素琪3.3种分子量的壳聚糖对香蕉枯萎病病原菌室内抑菌活性测定 [J], 占魏;张欣;吕延超;张贺;王芳;邱晓聪;谢艺贤4.生物杀菌剂对草莓枯萎病菌室内抑菌活性的测定 [J], 魏嘉怡;史芳芳;周明冬5.植物提取物对瓜类枯萎病菌的抑菌活性 [J], 曹冬煦;薛广厚;啜文婷;李颖;张宇;傅雷;于生成;范海延因版权原因，仅展示原文概要，查看原文内容请购买。
实验室落菌种类摘要：归纳了组织培养中污染原因及不同污染原因所造成的表观现象,并概括了解决外植体引发污染的方法。
发现棒杆菌属( Corynebac2terium) 、肠杆菌属( Enterobacter) 、葡萄球菌属( S taphylococus) 、地霉属( Geot richum) 、曲霉属( Aspergillus) 、毛霉属( Mucor) 、根霉属( Rhizopus) 等常见的细菌和真菌是引起组培苗严重污染的主要菌类。
取样测试鉴定表明,大部分的微生物来源于无菌接种室内的空气、超净工作台鼓风机排出的气体。
研究了壳聚糖对该菌的抑制作用，探索了3 种分子量及其6 种浓度的壳聚糖对该菌的抑制效果。
壳聚糖对该污染菌有抑制作用，5 万和25 万分子量的抑菌效果高于3000 分子量，浓度越高，抑菌效果越好。
初步证实了壳聚糖对组培污染菌类有很好的抑制作用，在花卉组织培养污染防治方面具有应用价值。
关键词植物组织培养;污染;外植体;灭菌组织培养；污染；壳聚糖；抑制作用从德国植物生理学家Haberlandt1902 年提出设想到现在,植物组织培养的研究已有100 多年的历史,近几十年来植物组织培养技术发展最为迅速。
然而植物组织培养一些技术环节仍然存在不少问题,其中污染、褐化、玻璃化被认为是组织培养的三大杀手。
与褐化、玻璃化相比污染更易发生,给科研和生产实践带来巨大的危害。
因此采取有效的防控措施,降低污染发生的机率,是组织培养成功的重要保障。
在众多污染途径中,外植体携带微生物污染组织培养是最常见且不易解决的问题。
笔者通过对相关文献的分析,并结合实践,归纳了组织培养过程中引起污染的原因及各种污染的表观现象,提出解决外植体引发污染的措施。
1 污染的原因及其表观现象污染就是在组织培养过程中微生物进入培养体系,在外植体上、外植体周围的培养基以及培养基的其他部位生长。
由于植物组织培养过程中的温度、湿度、营养、pH 值等适宜微生物的生长,因此一旦微生物进入培养容器中就将快速繁殖,通过营养竞争、侵蚀植物材料、分泌有毒代谢产物等途径使植物材料发生病害或死亡,造成组织培养的失败。
壳寡糖抑制植物病原菌生长的研究
胡健;姜涌明;殷士学
【期刊名称】《扬州大学学报：自然科学版》
【年(卷),期】2000(3)2
【摘要】研究了平均分子量 50 0～ 2 0 0 0的壳寡糖对棉花炭疽病菌
( Macrophomina phaseolina)和小麦赤霉病菌 ( Fusarium graminearum)等植物病原真菌和水稻白叶枯病菌 ( Xanthomonas oryzae)、马铃薯环腐病菌
( Clavibacter michiganensis)、棉花角斑病 ( Xanthomonas campestris)等植物病原细菌生长的影响 .结果表明 :不同分子量的壳寡糖对各种植物病原细菌的生长及植物病原真菌孢子萌发形成菌丝体均有明显的抑制作用 ,抑制作用的大小因壳寡糖分子量、浓度、植物病原菌的不同而有差异 .
【总页数】3页(P42-44)
【关键词】壳寡糖;植物病原菌;抑制作用;生长;棉花炭疽病菌
【作者】胡健;姜涌明;殷士学
【作者单位】扬州大学农学院农学系;扬州大学生物科学与技术学院生物技术系【正文语种】中文
【中图分类】S432.4
【相关文献】
1.低聚壳寡糖植物生长调节剂对丹参生长及次生代谢产物的影响 [J], 张元;林强
2.壳寡糖对植物病原真菌抑制效果的影响因素研究 [J], 陶凤云;林强;赵伟
3.壳寡糖对植物病原真菌的抑制作用 [J], 刘晓宇;刘志恒;吕淑霞
4.壳寡糖对烟草赤星病病原菌的抑制作用 [J], 胡国元;胡坚;李超影;杨春雷;袁军;余君;杨锦鹏
5.新型植物生长调节剂壳聚寡糖在果蔬作物上的应用研究 [J],
因版权原因，仅展示原文概要，查看原文内容请购买。
壳聚糖中胺基对其抑菌性能的影响及与DNA的作用李小芳;冯小强;伏国庆;杨声;苏中兴【摘要】采用抑菌圈法研究了壳聚糖对大肠杆菌(E.coli)和金黄色葡萄球菌(St.aureus)的抑菌活性.利用壳聚糖的席夫碱反应,对壳聚糖的胺基进行保护后,研究了壳聚糖中胺基对其抑菌性能的影响.同时,运用紫外吸收光谱和电化学的方法,研究了壳聚糖与DNA的相互作用,提出了壳聚糖对E.coli和St.atueus的抑菌机理.研究结果表明,壳聚糖对E.coli和St.aureus具有很好的抑制作用,且抑菌活性与其胺基有关;壳聚糖能与细胞内带负电的核酸结合,使细胞正常DNA复制生理功能受到影响,抑制细菌的繁殖,从而达到抑菌的目的.【期刊名称】《天然产物研究与开发》【年(卷),期】2010(022)003【总页数】6页(P373-377,470)【关键词】壳聚糖;抑菌活性;希夫碱;胺基;DNA【作者】李小芳;冯小强;伏国庆;杨声;苏中兴【作者单位】天水师范学院,生命科学与化学学院;天水师范学院,生命科学与化学学院;天水市中医医院化验科,天水,741001;天水师范学院,生命科学与化学学院;兰州大学化学化工学院,兰州,730000【正文语种】中文【中图分类】Q946.91;R285壳聚糖(Chitosan,简称 CTS)是甲壳素脱乙酰的产物,来源丰富、无毒,是可吸收降解的直链状高分子化合物。
壳聚糖及其衍生物具有广谱的抗菌性能,可抑制多种细菌和真菌的生长[1-5]。
但是,就其确切的抑菌机理目前尚不清楚。
Young等认为壳聚糖可吸附于细菌表面,与细菌细胞膜作用而改变其通透性[6];Helander等提出,壳聚糖对革兰氏阴性菌的抑菌作用是由于细胞外膜被破坏,最终造成菌体死亡[7];Hadwiger提出以细菌分子中DNA为作用靶向的抗菌机理[8];Tokura等认为壳聚糖吸附细菌后,壳聚糖分子包埋了整个细胞,抑制了细菌的呼吸和营养物质的进入而导致细菌死亡[9];Papineu等研究认为壳聚糖的抑菌作用可能是由于它导致了细胞内物质的泄漏而引起的[10]。
外文资料翻译CHITOSAN ON ANDRAEANUM TISSUE INHIBITIONOF BACTERIACONTAMINATIONAbstract: The fungi was isolated and purified from polluted anthurium subculture medium, identified to be DeuteromycotinaHyphpmycetesHyphomycetalesDematiaceae and trichoderma. The inhibition effect of the three kinds of chitosan on the fungi wasconducted.The results showed that the chitosan had inhibition effect on the fungi. The higher concentrations of chitosan had a betteinhibition effect than the lower ones.The inhibition effect of 50000 and 250000 molecular weight chitosan is better than that of the3000 molecular weight. It is preliminarily proved that chitosan had good inhibition effect on the fungi from polluted tissue culture ,andwill have good application value in the fields of pollution prevention in flowers tissue culture.Key words: tissue culture; contamination; Chitosan; inhibition effectPlant tissue culture, not only in plant breeding, rapid propagation of seedlings and the production of useful secondary metabolites, such as the use of a wide range of plant genetic engineering is and Plant Molecular Biology, one of the important foundation for the study [1]. Pollution, browning, glass and tissue culture are the main problems, including pollution of the most common[2]. Therefore take effective prevention and control measures to reduce the chance of contamination occurred, tissue culture is an important guarantee for success. Chitosan (chitosan) is the chitin in strong alkaline conditions from BAfter the formation of acyl an important derivative is determined by a number of N-acetyl glucosamine through β-(1-4) glycosidic bond linking the nature of it more lively. Has natural antibacterial properties of chitosan, and a broad spectrum antimicrobial, in recent years, chitosan in various fields such as agriculture，medicine [3], manufacture [4], food [5], etc. The use of great importance. Tissue culture of the chitosan in the application of inhibition has not been reported. This experiment to be from the contaminated medium subculture andraeanum extraction, purification and identification of bacteria contamination, with different molecular weight chitosan and different concentrations of their inhibition, and explore the best inhibitory effect of chitosan molecular weight and the best inhibitory concentration, in order to explore the chitosan as a new type of antimicrobial agent to provide specific information.1 Materials and Methods1.1 Test materials1.1.1 IsolatesStreptomyces bacteria pollution (code-named WCHPA), separated from the laboratory contamination andraeanum subculture medium.1.1.2 Test for DrugsChitosan, a Zhejiang Xing Biotechnology Australia Limited, a molecular weight of 3kd (degree of deacetylation> 80%), 50kd (degree of deacetylation> 90%), 25kd (degree of deacetylation> 90%)[6].1.1.3 Medium PDA mediumPotatoes 200g, glucose 20g, agar 20g, distilled water 1000ml, pH value of the natural.1.2 Test Method1.2.1 Isolation and purificationClean out the work in Taichung andraeanum subculture medium pollution fungi, from PDA medium. Repeat several times until the colony characteristics and morphology changes are no longer, we can identify bacteria have been purified.1.2.2 Identification of bacteria contaminationContinuous observation of colony morphology after purification. Film production equipment to further observe the shape strain, mycelium, spores, spore cell spore cell morphology and conidiation of the ways and forms and so on, taking pictures with a digital microscope.1.2.3 Bacteriostatic TestThat the different molecular weight chitosan with 1M solution of acetic acid dissolved mixed with PDA medium to produce a final concentration of chitosan (0.5,1.0,1.5,2.0,2.5,3.0)mg/ml of culture medium, 1M solution of sodium hydroxide by adjusting pH value of 6.0, in addition to the control without chitosan, the other with the addition of chitosan in the same medium[7]. To eliminate all high-pressure cooker sterilization 30min under 121 ℃and pour plate. Mycelium white to green after 24h and then into a brown, hyphae developed, velvet-like, 3d training around the middle of the brown and white flocculent mycelium of fimbriae produced. Hyphae are separated from a long stalk conidia to produce lateral branches whorled branches meristematicconidiation short bottles. Single-cell conidia oval, smooth.2 Results and Analysis2.1 Andraeanum symptoms subculture medium pollutionAndraeanum subculture in growth medium brown Fimbriae, medium surface was black, brown and white mycelium on the flocculation between the hyphae.2.2 fungal pure culture and identification of the resultsPDA medium in the upper colony diameter, edge neatly, spore germination of the PDA medium by adding chitosan, 4d clearly observed after the colony is surrounded by a black halo, black halo and colony growth as to the relocation of . The better the general inhibitory effect of the more obvious black halo[8]. Colony has no control this phenomenon. Chitosan molecular weight and concentration of the bacteriostatic effect.2.3. The same three concentrations of the bacteriostatic effect of chitosan molecularweight comparedConcentration of 0.5mg/ml 3 species of molecular weight chitosan WCHPA colony inhibitory effect of six concentrations of three kinds of molecular weight of chitosan on the inhibition rate of colony WCHPA results 0.5mg/ml concentration of three kinds of molecular weight chitosan there is no clear law, the maximum inhibitory rate of 50,000 in molecular weight of chitosan for the culture medium for 20.45%. Inhibitory rate and the time and no close ties. The results show that the concentration of 0.5mg/ml of the three kinds of molecular weight of the antibacterial effect of chitosan has not been satisfactory[9]. 5d prior to the first three kinds of chitosan molecular weight the greater the inhibitory rate of the higher molecular weight, and are extended over time to reduce the rate of inhibition. In paragraph 5d, 3000 molecular weight inhibitory rate of more than two other inhibitory rate of molecular weight, molecular weight and inhibition rate of 3000 also reached the highest value. At its bacteriostatic effect after 7d and 5d is similar to before, the greater the inhibitory rate of the higher molecular weight.3 Discussion and conclusions3.1 Chitosan as a potential new antibacterial agentsPollution plant tissue can be broadly divided into two types of operations may produce air pollution mainly mold contamination; explants is itself brought about by bacteria primarily by fungal and bacterial contamination[10]. High inhibitory rate was as high as 79.55%. Antibiotics in tissue culture is now the most common molecular weight of chitosan and 3.2 have an important impact on antimicrobial properties of the experimental results from the 50,000 and 250,000 the bacteriostatic effect of chitosan molecular weight than that of 3000; the highest inhibitory rate in the 250,000 molecular weight concentration of 3.0mg/ml and 2.0mg/ml of the two. But on the whole, taking into account the factors of price and its operation to the conclusion that the experimental molecular weight of 50,000 as the best concentration of 1.5mg/ml. 3.2 Concentration on the antimicrobial properties of chitosan have a significant impactQiu-ping [11], The results show that the antimicrobial effect of chitosan with its concentration increases, the experimental results support the results of the study. A wide range of applications of chitin, chitosan in the medical, food, environmental protection, in areas such as chemical products have wide-ranging and important applications. Chitosan flowers will be used for tissue culture would be very good prospects.References[1]MK.Razdan. Zun-Xiao-an, ZHU Yang translation.Introduction to Plant Tissue Culture [M]. Beijing: Chemical Industry Press ,2006:1-2.[2]Hu, ZHANG Li-jun,baixuemei, et al. Plant Tissue Culture Pollution Analysis and the disinfection of explants [J]. Anhui Agricultural Science, 2007,35 (3) :680-681.[3]Yi-Ting Wang,wanglianping , Mou Hero, et al. Industrial production of tissue culture studies of pollution and its control [J]. Anhui Agricultural Science, 2005, 33 (12): 2357 - 2358.[4]Chiang big.Chitin [M]. Beijing: China Environmental Science Press, 1996.[5]Fu Tian Xia, LIU Xiao-yu, Liu Zhiheng.Chitosan's antibacterial properties of the progress of applied research [J]. Liaoning Chemical, 2005,1234 (12) :541-544. [6]Yu Hanshou, Wu Zhang, Yang Bing. Chitosan inhibit research progress of plant diseases[J].Natural products research and development,1999,12 (3) :94-97.[7]Li Fang,shishaowei. Chitosan Preparation and application in the food industry Mechanism [J]. Food and Drug, 2006 (03A) :19-22.[8]Wu, Xia water.Non-biological factors on the antibacterial activity of chitosan [J]. Food Science, 2004,25 (7) :53-55.[9]wuxiaoyong, Qing-Xiao Zeng, MOshaofang. Several of the antibacterial properties of chitosan [J]. Food and Fermentation Industry, 2005,206 (2) :18-21. [10]Hu, ZHANG Li-jun,baixuemei, et al. Plant Tissue Culture PollutionAnalysis and the disinfection of explants [J]. Anhui Agricultural Science, 2007,35(3) :680-681.[11]Qiu-ping, Chitosan on mango Colletotrichumgloeosporioides, Diplodiaantagonism bacteria [J]. Food and machinery, 2005,21, (1) :25-27.壳聚糖对红掌组培污染菌的抑制作用摘要：在污染的红掌继代培养基中提取污染菌并进行了分离及纯化，初步鉴定为为半知菌亚门（Deuteromycotina),丝孢纲（Hyphpmycetes),丝孢目（Hyphomycetales）,淡色孢科（Dematiaceae）,木霉属（trichoderma）。
