Background： A series of modified montmorillonites（Mt） including zinc-loaded Mt（Zn-Mt）, copper-loaded Mt（Cu-Mt）, copper/zinc-loaded Mt with different Cu/Zn ratio（Cu/Zn-Mt-1, Cu/Zn-Mt-2, Cu/Zn-Mt-3） were prepar...Background： A series of modified montmorillonites（Mt） including zinc-loaded Mt（Zn-Mt）, copper-loaded Mt（Cu-Mt）, copper/zinc-loaded Mt with different Cu/Zn ratio（Cu/Zn-Mt-1, Cu/Zn-Mt-2, Cu/Zn-Mt-3） were prepared by an ion-exchange reaction, and characterized using X-ray diffraction（XRD）, fourier transformed infrared spectroscopy（FTIR） and transmission electron microscopy（TEM）. The specific surface areas, antimicrobial activity and cytotoxicity of the modified Mt were investigated.Results： In the modified Mt, hydrated Cu ions and Zn ions were exchanged in the interlayer space of Mt and the particles were irregular shapes. The results showed that Cu/Zn-Mt enhanced antibacterial and antifungal activity compared with Zn-Mt and Cu-Mt possibly due to the synergistic effect between Cu and Zn. Among the Cu/Zn-Mt with different Cu/Zn raitos, Cu/Zn-Mt with a Cu/Zn ratio of 0.98 or 0.51 showed higher antimicrobial activity against gram-negative bacteria（Escherichia coli）, gram-positive bacteria（Staphylococcus aureus）, fungi（Candida albicans）.Moreover, the antimicrobial activity of Cu/Zn-Mt was correlated with its specific surface area. Cytotoxicity studies on IPEC-J2 cell showed a slight cytotoxicity of Cu/Zn-Mt.Conclusions： The current data provide clear evidence that in terms of its antimicrobial activity and relatively low toxicity, the Cu/Zn-Mt holds great promise for applications in animal husbandry.展开更多
Zn-montmorillonites（Zn-MMTs） as antibacterial compounds were prepared by an ion-exchange reaction. The reaction time, initial pH value and molar ratios of CEC influencing zinc content in Zn-MMTs were investigated, a...Zn-montmorillonites（Zn-MMTs） as antibacterial compounds were prepared by an ion-exchange reaction. The reaction time, initial pH value and molar ratios of CEC influencing zinc content in Zn-MMTs were investigated, and Zn-MMTs were characterized by means of EDX, XRD, XPS, and SEM. The results of bacterial growth tests were confirmed by determination of the minimum inhibition concentrations （MICs） and minimum bactericidal concentrations （MBCs）. The experimental results show that the zinc is confirmed as bivalent zinc state, the d001 basal spacing of Zn-MMTs is enlarged with the enhancement of the zinc content, and the particles of Zn-MMTs are formed with irregular shape. Moreover, the antibacterial activity of Zn-MMTs increases with increasing the zinc content, and Zn-MMT-3 containing 6.76 mass% of zinc exhibits optimum antibacterial activity against Escherichia coli and Staphylococcus aureus.展开更多
基金supported by the Special Fund for Agro-scientific Research in the Public Interest(No.201403047)Science Technology Department of Zhejiang Province(2015C02022)
文摘Background： A series of modified montmorillonites（Mt） including zinc-loaded Mt（Zn-Mt）, copper-loaded Mt（Cu-Mt）, copper/zinc-loaded Mt with different Cu/Zn ratio（Cu/Zn-Mt-1, Cu/Zn-Mt-2, Cu/Zn-Mt-3） were prepared by an ion-exchange reaction, and characterized using X-ray diffraction（XRD）, fourier transformed infrared spectroscopy（FTIR） and transmission electron microscopy（TEM）. The specific surface areas, antimicrobial activity and cytotoxicity of the modified Mt were investigated.Results： In the modified Mt, hydrated Cu ions and Zn ions were exchanged in the interlayer space of Mt and the particles were irregular shapes. The results showed that Cu/Zn-Mt enhanced antibacterial and antifungal activity compared with Zn-Mt and Cu-Mt possibly due to the synergistic effect between Cu and Zn. Among the Cu/Zn-Mt with different Cu/Zn raitos, Cu/Zn-Mt with a Cu/Zn ratio of 0.98 or 0.51 showed higher antimicrobial activity against gram-negative bacteria（Escherichia coli）, gram-positive bacteria（Staphylococcus aureus）, fungi（Candida albicans）.Moreover, the antimicrobial activity of Cu/Zn-Mt was correlated with its specific surface area. Cytotoxicity studies on IPEC-J2 cell showed a slight cytotoxicity of Cu/Zn-Mt.Conclusions： The current data provide clear evidence that in terms of its antimicrobial activity and relatively low toxicity, the Cu/Zn-Mt holds great promise for applications in animal husbandry.
基金Funded by the National Natural Science Foundation of China (Nos. 20676049, 20871058 and 20971028)the Foundation of Enter-prise-University-Research Institute Cooperation from Guangdong Province and Ministry of Education of China (Nos. 2007B090400105 and2008A010500005)the Open Fundation of Guangdong Provincial Key Laboratory of Applied Microbiology (No. SWKF200704)
文摘Zn-montmorillonites（Zn-MMTs） as antibacterial compounds were prepared by an ion-exchange reaction. The reaction time, initial pH value and molar ratios of CEC influencing zinc content in Zn-MMTs were investigated, and Zn-MMTs were characterized by means of EDX, XRD, XPS, and SEM. The results of bacterial growth tests were confirmed by determination of the minimum inhibition concentrations （MICs） and minimum bactericidal concentrations （MBCs）. The experimental results show that the zinc is confirmed as bivalent zinc state, the d001 basal spacing of Zn-MMTs is enlarged with the enhancement of the zinc content, and the particles of Zn-MMTs are formed with irregular shape. Moreover, the antibacterial activity of Zn-MMTs increases with increasing the zinc content, and Zn-MMT-3 containing 6.76 mass% of zinc exhibits optimum antibacterial activity against Escherichia coli and Staphylococcus aureus.
