50种植物提取物对梨褐斑病菌抑菌活性

采用生长速率法测定了50种植物提取物对梨褐斑病菌的抑菌活性。结果表明,广西地不容块根、龙葵枝叶、狭叶十大功劳根茎和广西蜘蛛抱蛋全株的抑菌活性较高。用质量浓度为10g／L的药液处理,72h的抑菌率分别为100％、80．98％、76．19％和73．65％;南蛇勒嫩茎、射干全株、银杏外种皮、黄柏树皮和黄堇全株的抑菌率在50．63％～60．05％之间;其余植物提取物的抑菌率在50％以下。进一步测定了广西地不容块根、龙葵枝叶、狭叶十大功劳根茎和广西蜘蛛抱蛋全株4种提取物对梨褐斑病菌的毒力,它们的有效中浓度（EC50）分别为1．2525、3～973、1．7980和3．4131g／L。     

藜芦乙醇提取物对植物病原真菌的抑菌活性研究

通过测定藜芦的乙醇提取物以及各萃取部分对植物病原真菌的抑菌活性,寻找藜芦中的农用活性物质,为其综合开发利用提供科学依据。采用菌丝生长速率法测定了藜芦球茎和根乙醇提取物对6种植物病原菌的抑制作用。试验结果表明,当供试浓度为5.0 mg/mL时,对苹果腐烂病菌(Valsa mali)、棉花枯萎病菌(Fusarium oxysporum f.sp.vasinfectum)和苹果轮纹病菌(Physalospora piricola nose)的抑菌率比较高,分别为96.4%、78.1%和74.3%。藜芦乙醇提取物的不同极性溶剂萃取物的抑菌活性较高,乙酸乙酯萃取物对苹果腐烂病菌和苹果轮纹病菌的EC50分别为0.161 mg/mL和0.551 mg/mL;正丁醇萃取物对苹果腐烂病菌和苹果轮纹病菌的EC50分别为0.190 mg/mL和0.451 mg/mL。乙酸乙酯萃取物是进一步研究的重点。     

4种壬菌铜细菌专用配方的抑菌活性筛选

采用抑菌圈法测定4种壬菌铜细菌专用制剂对白菜软腐病菌和水稻向叶枯病菌室内毒力,结果表明：壬菌铜细菌专用1号、2号、3号均对白菜软腐病菌有不同程度的抑制作用;1号和2号均对水稻白叶枯病菌有抑制活性。其巾壬菌铜细菌专用1号对供试的2种病菌的抑制作用最显著,EC50分别为30．66mg／L和46．25mg／L。     

6种植物提取物对非洲菊疫病病菌的抑菌活性筛选

选用田间常见的6种植物,用蒸馏水对其进行浸提,经旋转蒸发仪浓缩得到植物提取物.大多数提取物对非洲菊疫病病菌菌丝生长都有不同程度的抑制作用,其中白蒿提取物对菌丝生长抑制效果最好,抑制率达91.46%,桉树、青蒿次之,抑制率分别为70.00%、62.20%,紫茎泽兰、芹菜抑制效果较差,分别为31.77%、3.43%,而蛇床子无抑制效果.根据菌丝生长抑制试验和离体抑菌试验结果,选取抑制效果较好的3种植物提取物用于非洲菊疫病的田间防治试验.结果表明青蒿、桉树的植物提取物对非洲菊疫病的田间相对防治效果分别为86.58%、65.92%,可用于新型植物农药的开发利用.     

20种植物提取物对植物病原细菌的抑制活性

[方法]以水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae)、桃树细菌性穿孔病菌[Xanthomonus campestrispv.pruni(Smith) Dye.]为供试菌,对20种植物提取液进行抑菌活性筛选;采用液-液萃取法初步分离石榴皮、五倍子的抑菌活性成分.[结果]石榴皮、五倍子对2种病原细菌抑制效果最好;石榴皮的抑菌活性成分主要存在于正丁醇萃取层,五倍子乙酸乙酯萃取物的抑菌活性成分较好.[结论]石榴皮对2种病原细菌的抑制活性最好,其正丁醇萃取物是下一步研究的重点.     

荆条乙醇提取物对植物病原真菌的抑菌活性初步研究

探索荆条的抑菌活性,为综合开发利用提供科学依据。采用生长速率法测定了荆条花和叶的乙醇提取物以及各萃取物对植物病原真菌的抑制作用。结果表明:荆条花乙醇提取物的抑菌活性好于叶。当供试质量浓度为5.0 g/L时,花的乙醇提取物对苹果腐烂病菌、白菜黑斑病菌、番茄早疫病菌和棉花枯萎病菌的抑菌率分别为87.72%、77.32%、72.69%和71.37%。荆条花乙醇提取物不同溶剂萃取物中,石油醚和乙酸乙酯的抑菌活性较高。石油醚萃取物和乙酸乙酯萃取物对苹果腐烂病菌的EC50值分别为0.32 g/L和0.23 g/L;石油醚萃取物和乙酸乙酯萃取物对白菜黑斑病菌的EC50值分别为0.45 g/L和0.20 g/L。石油醚萃取物是进一步研究的重点。     

牡丹皮乙醇提取物对黄瓜枯萎病菌的活性抑制及作用机制

为探究牡丹皮对黄瓜枯萎病菌(Fusarium oxysporum f.sp.cucumerinum)的抑菌活性,通过用不同浓度的牡丹皮乙醇提取物处理黄瓜枯萎病菌,测定其对枯萎病菌的菌丝生长抑制率、胞外电导率、A_{260 nm}与A_{280 nm}的变化,使用光学显微镜观察处理后的菌丝形态变化。结果表明：牡丹皮乙醇提取物处理后的黄瓜枯萎病菌胞外电导率、A_{260 nm}和A_{280 nm}显著上升,菌丝出现膨胀畸变等现象;其中质量浓度为25.0 mg/mL的牡丹皮乙醇提取物可显著降低黄瓜枯萎病菌的生长速度,处理48 h后抑菌率可达到92.08%;进一步研究认为,牡丹皮通过破坏黄瓜枯萎病菌的细胞膜结构,使胞内物质渗出,造成菌丝形态结构畸变,进而抑制了菌体细胞的生长与繁殖。     

紫茉莉提取物的抑菌活性

紫茉莉是紫菜莉科的一种多年生草本植物.通过对其根、茎与叶提取物抑菌活性的室内测试结果表明:紫茉莉根甲醇提取物与茎甲醇提取物对梨黑斑病菌和西瓜炭疽病菌菌丝生长具有较好的抑制作用.其巾根甲醇提取物对以上2种病原真菌菌丝生长的抑菌率分别为85.49%和84.78%、茎甲醇提取物为98.36%和75.38%;此外,该2种提取物对梨黑斑病菌、西瓜炭疽病菌与草莓灰霉病菌孢子的萌发也具有较好的抑制效果.前者对以上3种病原真菌孢子萌发的抑制率依次为90,50%、73.39%、77.94%;后者分别为89.91%、84.03%和75.90%.     

洋葱提取物抑菌活性研究

采用70%乙醇提取洋葱,将其提取液经过三种不同溶剂萃取,萃取物对土壤中的放线菌、细菌及真菌的抑菌活性进行实验研究,测定并比较不同萃取物对土壤放线菌、细菌、真菌的抑菌活性。对土壤放线菌、细菌、真菌抑制效果最好的溶剂萃取物分别为石油醚、乙酸乙酯、正丁醇,其抑菌率依次为51.1%,75.1%,77.3%。洋葱的不同溶剂萃取物抑菌效果不同,且同一萃取物对土壤不同种类微生物的抑制效率亦不同。     

大蓟提取物对植物病原真菌的抑菌活性成分研究

[目的]大蓟有广泛的生物活性,具有生物农药的开发潜力。确定其中抗植物病原菌的主要活性成分,以期为其在农药领域的开发利用提供依据。[方法]通过溶剂提取法提取,用生长速率法测定提取物对5种植物病原真菌的抑菌活性,并用柱层析法分离活性物质。[结果]在质量浓度50 g/L时石油醚提取物对石榴枯萎病菌的抑菌活性最高,抑制率达100%,EC50值为5.1 g/L;从中分离出一个三萜类单体化合物,经鉴定为3β,21β-dihydroxyl-20(30)-en-taraxastane。[结论]大蓟对植物病原真菌有良好的抑菌活性,所分离到的单体化合物为大蓟中的主要抑菌活性成分。     

大白菜软腐病菌16S rDNA序列比对鉴定及杀菌剂对其生物活性测定试验

[目的]大白菜软腐病是影响白菜正常生长的重要病害,严重影响白菜的产量和品质.化学防治是控制大白菜软腐病的重要措施.为了进一步明确甲氧基丙烯酸酯类和抗生素类药剂对大白菜软腐病的防治效果,开展试验研究.[方法]从腐烂大白菜叶片分离得到大白菜软腐病菌(Erwinia carotovora subsp.carotovora),采用16S rDNA序列比对的方法对其进行鉴定.将其作为防治对象,测试杀菌剂的生物活性.[结果]不同药剂对大白菜软腐病菌的生物活性差异很大,同一药剂在离体试验和活体试验中的结果也并不相同.[结论]由于药剂的生物活性测试结果在离体和活体试验中表现出差异性,需要将2种试验方法相结合,才能对药剂生物活性进行准确评价.     

Efficacy of Ozonated Water Against Erwinia carotovora subsp. carotovora in Brassica campestris ssp. chinensis

Erwinia carotovora subsp. carotovora (Ecc) is a bacterial pathogen that causes decay of vegetables and is found in a wide range of Brassica crops in the Shanghai area, particularly in non-heading Chinese cabbage (NHCC). In this study, aqueous ozone was used as an antimicrobial agent to prevent the growth of Ecc bacterial colonies. Ecc that were treated with aqueous ozone were completely inactivated after the bacteria had been exposed to 0.5 mg/L ozone at 28 °C. Furthermore, a susceptible NHCC cultivar was directly sprayed with different concentrations of dissolved ozonated water as a pesticide substitute. The effects of the treatments on morphology were analyzed, and some treatments were characterized by induction of visible symptoms of senescence. No negative effects were observed after treatment by spraying ozonated water compared with the control at concentrations below 8 mg/L. However, visible damage to leaves was observed after the plants were exposed to 10 mg/L ozonated water via spraying for 15 days during the plant reproductive stage. Additionally, enzyme activities and antioxidant responses gradually increased to a certain degree and then decreased in the untreated and ozonated water-treated plants. These results showed that ozonated water was effective in restraining pathogens and potentially defending against disease in growing NHCC plants within a certain concentration range. These results provide a theoretical basis for preventing disease by applying ozonated water to vegetables as an alternative to pesticides.     

Antibacterial activity and mechanism of piperazine polymer

Piperazine polymers poly(ethylenediaminetetraacetic dianhydride-co-piperazine) (PE) and MGF-Ct24E-modified poly(ethylenediaminetetraacetic dianhydride-co-piperazine) (PEM) showed good antibacterial activity. Considering their different applications, the effects of time, pH, and inoculation concentration of these antibacterials against Escherichia coli (E. coli) in unique environments were evaluated in this study. The results indicated that the MIC and MBC values of the polymers increased after the introduction of MGF-Ct24E into PE, but the two types of polymers still exhibited good antibacterial activity in a short time period under acidic conditions. In addition, we investigated the effect of the piperazine polymers on bacterial cell structure. It was clear that PE and PEM could destroy the bacterial cell wall, cell membrane and DNA, and their specific mechanism may be different. For PE, its carboxyl group could react with peptidoglycans on the E.coli cell wall to form holes on the bacterial surface, allowing PE to penetrate into the bacterial cell to damage DNA. For PEM, the alkaline MGF-Ct24E could adsorb E.coli and make it shrink, meanwhile, the PE component created small holes on the bacterial walls and membranes, and inserted into the bacteria to result in bactericidal effect. These findings reveal the potential usefulness of PE and PEM in biomedical applications.     

Antibacterial activity of modified polyamide fibers

Polyamide fibers were modified for the attainment of antibacterial activity using a graft copolymerization method. The fibers were grafted with monomers containing quaternary ammonium groups using sodium persulfate as initiator. Two monomers were used as vinyl monomers. The first monomer, called METAC, is methacryloyloxyethyl trimethylammonium chloride [H₂C = C(CH₃)‐ CO₂CH₂CH₂N(CH₃)₃Cl]. The second monomer, denoted CATAL, is a methacryloyloxyethyl dimethyldodecylammonium bromide [H₂C = C(CH₃)CONHCH₂CH₂CH₂N‐ (CH₃)₂(C₁₂H₂₅)Br], kindly supplied by Catalyze (France). The graft copolymerization was confirmed by several methods such as elemental analysis and FTIR spectroscopy. The antibacterial activity of modified samples was investigated against Staphylococcus aureus using the antibacterial standard AFNOR test method XP G39–100. Polyamide fibers grafted with the second monomer exhibit high antibacterial activity against S. aureus, but the fibers grafted with the methacryloyloxyethyl trimethylammonium chloride did not. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 997–1000, 2005     

壳聚糖抗菌活性研究进展

壳聚糖具有无毒、良好的生物相容性、生物可降解性、广谱抗菌性等优良性能,作为新型抗菌剂越来越受学者的青睐。本文主要综述了21世纪以来影响壳聚糖抗菌性能的因素、壳聚糖的抗菌机理以及壳聚糖衍生物抗菌性能等方面的内容。     

新型具备抑菌活性阴离子型表面活性剂的抑菌性与表面活性的关系研究

本论文利用一种新型具备抑菌活性的阴离子型表面活性剂为实验材料,选取大肠杆菌及金黄色葡萄球菌作为目标菌种,通过纸片扩散法对其抑菌活性进行了研究,利用吊片法对其水溶液的表面张力进行了测定,并研究了其抑菌活性与表面活性的关系,讨论了其抑菌机理。     

Antibacterial activity of cationically modified cotton fabric with carboxymethyl chitosan

A water‐soluble carboxymethyl chitosan was prepared with a view to develop a multifunctional finish on cotton. Carboxymethyl chitosan (CMCTS) was synthesized by chemical reaction of chitosan with monochloroacetic acid under alkaline condition. The water soluble CMCTS was applied to cationized cotton with different concentrations. The treated fabrics were characterized through monitoring the textile physical properties and for the antibacterial activity against Escherichia coli DSMZ 498 and Micrococcus luteus ATCC 9341. The results obtained show that the physical properties of the treated fabrics are improved by increasing the CMCTS concentration, as well as the antibacterial activity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

公、母丁香乙醇提取物离体抑菌活性比较

采用生长速率法和孢子萌发法测定了公丁香和母丁香的乙醇提取物对5种病原菌（番茄灰霉病菌、水稻稻瘟病菌、黄瓜炭疽病菌、苹果轮纹病菌和玉米小斑病菌）的菌丝生长和3种病原菌（番茄灰霉病菌、稻瘟病菌和玉米小斑病菌）孢子萌发的影响。结果表明,提取物对两者均有一定的抑制作用：对于同一种病原菌来说,丁香的乙醇提取物对其孢子萌发的抑制效果好于对其菌丝生长的抑制效果;在相同的供试浓度下,公丁香的抑菌效果优于母丁香。     

Antibacterial activity of silver‐doped manganese dioxide nanoparticles on multidrug‐resistant bacteria

BACKGROUND: As a result of evolution of multiple drug resistance in human pathogens (bacteria) there is increasing demand for novel antibacterial agents, and recently, due to their high antibacterial and catalytic activities, metal nanoparticles have attracted the attention of researchers and medical microbiologists worldwide. RESULTS: Ni‐, Ce‐ and Ag‐doped MnO₂ nanoparticles were synthesized by a co‐precipitation method. Antibacterial activity of these synthesized nanoparticles on methicillin‐resistant Staphylococcus aureus and lead‐resistant Pseudomonas aeruginosa strain 4EA was investigated using a disc diffusion method. Only Ag‐doped MnO₂ nanoparticles showed an antibacterial property against methicillin‐resistant Staphylococcus aureus and lead‐resistant Pseudomonas aeruginosa strain 4EA at low levels of 60 µg/disc and 85 µg/disc, respectively. Scanning electron microscopy and transmission electron microscopy (SEM‐TEM) coupled with energy dispersive X‐ray (EDX) analysis revealed the nano‐size and composition of these synthesized nanoparticles. CONCLUSION: It was confirmed through a disc diffusion method that chemically synthesized silver doped MnO₂ nanoparticles have antibacterial activity against multidrug‐resistant Staphylococcus aureus and lead‐resistant Pseudomonas aeruginosa strain 4EA at low levels therefore these nanoparticles can be employed to fight and prevent infections caused by multidrug‐resistant bacterial pathogens. © 2012 Society of Chemical Industry     

紫花地丁不同方式提取物抑菌效果研究

采用索式提取和微波2种方式分别对紫花地丁进行提取,并运用生长速率法测定了各提取物对植物病原真菌的抑制作用。实验结果表明:在4.0 g/L时,微波提取物的抑菌活性(最高86.9%)明显高于索式提取物的活性(最高64.7%)。丙酮提取物对棉花枯萎病菌、柑橘炭疽病菌和小麦全蚀病菌的EC50分别是3.04,2.90,2.78 g/L。