铜离子-氧化锌/十六烷基铵基吡啶-蒙脱石复合材料的抗菌活性研究

以大肠杆菌和鼠伤寒沙门氏菌为试验菌株,比较研究了铜离子-氧化锌/十六烷基铵基吡啶-蒙脱石复合材料(Cu2+-ZnO/CP-MMT)的抗菌活性。结果表明,Cu2+-ZnO/CP-MMT具有较高的抗菌活性,对大肠杆菌的最小抑菌质量浓度和杀菌质量浓度分别为80μg/mL和160μg/mL,对鼠伤寒沙门氏菌的最小抑菌质量浓度和杀菌质量浓度分别为40μg/mL和160μg/mL。Cu2+-ZnO/CP-MMT对所试菌均产生抗菌剂后效应和持续抑菌效应。320μg/mL的Cu2+-ZnO/CP-MMT能在12h内杀灭大肠杆菌和鼠伤寒沙门氏菌,而640μg/mL的Cu2+-ZnO/CP-MMT能在6h内杀灭大肠杆菌,4h内杀灭鼠伤寒沙门氏菌。

磁场处理对壳聚糖金属配合物抑制大肠杆菌作用的影响(英文)

壳聚糖(CS)是有丰富自然资源的甲壳素的脱乙酰基产物,壳聚糖及其衍生物具有优良的生物活性.文中报道了壳聚糖与铅、铜、铬等过渡金属离子所形成的壳聚糖金属配合物(CS-Cu、CS-Pb、CS-Cr)对大肠杆菌的抑制作用以及外加磁场处理对其抑菌作用的影响.采用琼脂扩散纸片法测定了各壳聚糖金属配合物对大肠杆菌的最低抑菌浓度,以此评了价壳聚糖金属配合物的抑菌能力.实验结果表明,各种壳聚糖金属配合物对大肠杆菌的抑制作用存在程度上的差异,以CS-Cr的抑菌效果最显著;外加磁场处理,能加强壳聚糖金属配合物对大肠杆菌的抑制作用,在场强为400 kA/m的磁场作用下,各种壳聚糖金属衍生物对大肠杆菌的最低抑菌浓度分别为CS-Cu:12.5 mg/mL,CS-Pb:6.25 mg/mL,CS-Cr:3.125 mg/mL.研究显示壳聚糖金属配合物在食品加工中有一定的应用前景.

Analysis of the Antimicrobial Activity of Antimicrobial Peptides Extracted from Immunized Tenebrio molitor Induced by Different Microbial Treatments Against 26 Pathogens

[Objective] The study was to explore whether antimicrobial activity of the antimicrobial peptides extracted from immunized Tenebrio molitor varied with different pathogens as inducers.[Method]By inducing T.molitor hungry larvaes to generate immune response via feeding with bacteria and with fungi or actinomycete post to pricking,the antimicrobial peptides extracts were obtained by grinding and centrifuging the cultures.Its antimicrobial activity against 26 pathogens was measured by bacteriostatic ring,and evaluated by trisection to four types and inhibitory spectrum.[Result]Both the antimicrobial activity and antimicrobial spectrum of the antimicrobial peptides extracts varied remarkably among different pathogens as inducers.[Conclusion]Bio-control used strains have obvious advantage in inducing the insect to express body fluid immunity material-antimicrobial peptides.

Isolation and Antifungal Evaluation of Rumex cyprius Murb Extracts

Ethanolic extract of dried Rumex cyprius Murb （polygonaceae） was tested against four pathogenic fungi： three dermatophytes, Microsporum canis, Trichophyton mentagrophytes and T. rubrum, and the causative agent of chalkbrood disease of bees, Ascophaera apis. The extract showed considerable activity against all these fungi. One of the main constituents ofRumex cyprius was isolated and tested for its antimycotic activity. It showed a significant activity against the test fungi and was identified as 1,3,8-trihydroxy-6-methylanthracene-9,10-dione based on its IR, UV-V and 1^H NMR spectra.

Scoping Antifungal Activities of Various Forms of Chitosan Oligomers and Their Potential Fixation in Wood

Chitosan oligomers （average Dp-4） are known for their antifungal activity and wood decay resistance. These oligomers are susceptible to moisture, and promote yeast growth upon air exposure after a sufficient length of time. Chitosan oligomers of three different states viz. completely dried, freshly prepared and highly viscous form, were prepared to compare their in-vitro antifungal activities against three brown-rot fungi, two sapstain and one mould fungus using agar nutrient medium. Additionally, a mixture of chitosan oligomers and boric acid was used for wood treatment. The nutrient medium bioassay results show that all states of chitosan oligomers inhibited the growth of tested basidiomycetes fungi, but not sapstain and mould fungi. Subsequently, wood decay results confirm antifungal activity of chitosan oligomers plus boron against basidiomycetes, but highlighted their leachability upon water exposure.

Determination of Antimicrobial Activity of Methyl Cellulose Films Enriched with Some Essential Oils on Listeria innocua

Essential oils are effective antimicrobials on important some pathogenic bacteria and can be added packaging materials due to absorb various surfaces. In this study, the aim is to determinate of antimicrobial effects of methyl cellulose films with containing various proportions thyme, rosemary, coriander, basil and pimento berry oils （1%, 2%, 3% and 4% g/cc） against important bacteria as a surface contaminant Listeria innocua by in vitro. For this purpose, 1 cm diameter discs were cut from methyl cellulose films containing essential oils and inhibition zone diameter which were measured by the agar diffusion method. As the results of these analyses, all prepared active edible methyl cellulose films were antimicrobial effects on Listeria innocua. The most powerful antimicrobial effect achieved with methyl cellulose film including coriander oil on Listeria innocua. And also the weakest antimicrobial effect achieved with methyl cellulose film including rosemary oil on Listeria. All results were significant by statistically （p 〈 0.01） and all analyses were replicated in three times.

Antioxidant and antibacterial activities of the ethyl acetate extracts of endophytic fungi isolated from Ageratum conyzoides L.

Accumulating evidence has demonstrated that endophytic fungi metabolites possess important biological activities.Ageratum conyzoides L.(Asteraceae)is an invasive aromatic herb with immense therapeutic importance.In the present study,we aimed to isolate and identify endophytic fungi in the roots,stems,leaves and flowers of Ageratum conyzoides L.and evaluate its antioxidant activity(DPPH,ABTS^(+) and FRAP assays),the contents of flavonoids and phenolic and antibacterial activity of their ethyl acetate extracts.Accordingly,a total of 25 endophytic fungi were isolated from Ageratum conyzoides L.and classified into 14 genera based on the Internal transcribed spacer sequence,among which Fusarium sp.(20%)were found to be the dominant groups.All fungal extracts exhibited antioxidant activity,and the extracts of fungi WZ07 exhibited antioxidant activities as well as higher flavonoids and phenolic content in all tests.Moreover,the extracts of fungi WL01 had good antibacterial activity against both Gram-positive and Gram-negative bacteria.We,for the first time,reported the antioxidant and antibacterial activity of endophytic fungi from Ageratum conyzoides L.,which may help lay the foundation for developing other medicinal components.

Anti-infectious efficacy of essential oil from Caoguo(Fructus Tsaoko)

OBJECTIVE: To evaluate the anti-infectious efficacy of essential oil extracted from Caoguo(Fructus Tsaoko).METHODS: Minimum inhibitory concentrations(MICs) against clinical isolates of three extracts andthe essential oil from Caoguo(Fructus Tsaoko) were determined by the agar dilution method. The anti-infectious efficacy of the essential oil was evaluated using a mouse peritonitis model which was infected with Staphylococcus aureus or Escherichia coli. The chemical components of the essential oil were identified.RESULTS: The results showed that the essential oil exhibited strong antibacterial activity in vitro, with MICs ranging from 22.49 to 1438.91 μg/m L. The results of in vivo anti-infectious efficacy showed that the Caoguo(Fructus Tsaoko) essential oil can protect the mice from Staphylococcus aureus or Escherichia coli infection. The compositions of the essential oil and relative component percentages were examined. A total of 32 compounds, were identified. The major compounds of essential oil were 1,8-cineole(25.92%) and geraniol(13.69%).CONCLUSION: Our findings suggest that Caoguo(Fructus Tsaoko) essential oil has broad-spectrum antibacterial properties. It warrants further investigation as an antibacterial agent targeting some bacterium with multi-drug resistance.