title: Microbial growth inhibition caused by Zn/Ag-Y zeolite materials with different amounts of silver.
abstract: Different loadings of silver exchanged on bimetallic Zn/Ag-NaY zeolite materials were studied for antimicrobial properties against four reference microorganisms. The sensitive indicator strains used were two bacteria (Escherichia coli and Bacillus subtilis) and two yeast species (Saccharomyces cerevisiae and Candida albicans). The bimetallic materials were compared with the monometallic materials prepared with the same concentrations of silver. A synergistic effect between the two metals, zinc and silver, was evidenced on the antimicrobial activity of the materials. All mono and bimetallic materials showed strong efficacy against bacteria and yeasts, although the later overall displayed lower MIC values. The results of X-ray photoelectron spectroscopy (XPS) confirm the presence of silver and zinc as ions, not homogeneously distributed throughout the zeolite framework, which implies that the metal ions are located in different sites of the faujasite structure.
authors.affiliation: Center of Chemistry, Chemistry Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Liliana
authors.initials: L
authors.lastname: Ferreira
authors.affiliation: Center of Chemistry, Chemistry Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal; CITAB (Center for the Research and Technology of Agro-Environmental and Biological Sciences), Biology Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Joana F
authors.initials: JF
authors.lastname: Guedes
authors.affiliation: CITAB (Center for the Research and Technology of Agro-Environmental and Biological Sciences), Biology Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Almeida-Aguiar
authors.affiliation: Center of Chemistry, Chemistry Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: António M
authors.initials: AM
authors.lastname: Fonseca
authors.affiliation: Center of Chemistry, Chemistry Department, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal. Electronic address: ineves@quimica.uminho.pt.
authors.forename: Isabel C
authors.initials: IC
authors.lastname: Neves
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D017641:Zeolites / Q000737:chemistry / Q000494:pharmacology*; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D017641:Zeolites; D012834:Silver; D015032:Zinc
keywords: Ag content; Antimicrobial activity; Ion-exchange; NaY zeolite; Zn/Ag