title: Biocidal and inhibitory activity screening of de novo synthesized surfactants against two eukaryotic and two prokaryotic microbial species.
abstract: Thirty-six quaternary ammonium salts, of which 28 structurally different non-commercially available surfactants, were tested to screen their biocidal and inhibitory antimicrobial activity. Their activity was compared to commercially available amphiphiles as well as to non-amphiphilic quaternary ammonium salts. As target of these compounds four microbial species were employed of which two (Saccharomyces cerevisiae and Candida albicans) were important yeast in the food and clinical environment and the other two (Escherichia coli and Listeria innocua) represented the Gram negative and positive bacteria, respectively. The surfactants showed the ability to kill the microbial cells in water solution and to variably hamper their growth onto agar medium. The non-amphiphilic compounds (which represent analogues of some surfactants used in this study, since they have the same head group but no hydrophobic portion) had little effect in solution and no effect against the microbial growth on plate. Amphoteric and non-amphoteric zwitterionic surfactants showed reduced biocidal activity. The most active antimicrobial agent was N-tetradecyltropinium bromide (23S) surfactant. The presence of cells did not significantly affect the ability to form micelles, as demonstrated by comparative conductometric measurements.
authors.affiliation: CEMIN, Centre of Excellence on Nanostructured Innovative Materials, Department of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 8, I-06123 Perugia, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Tiecco
authors.affiliation: Department of Applied Biology - Microbiology, University of Perugia, Borgo XX Giugno 74, I-06121 Perugia, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Cardinali
authors.affiliation: Department of Applied Biology - Microbiology, University of Perugia, Borgo XX Giugno 74, I-06121 Perugia, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Roscini
authors.affiliation: CEMIN, Centre of Excellence on Nanostructured Innovative Materials, Department of Chemistry, Biology and Biotechnology, University of Perugia, via Elce di Sotto 8, I-06123 Perugia, Italy.
authors.forename: Raimondo
authors.initials: R
authors.lastname: Germani
authors.affiliation: Department of Applied Biology - Microbiology, University of Perugia, Borgo XX Giugno 74, I-06121 Perugia, Italy. Electronic address: laura.corte@unipg.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Corte
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects; D004553:Electric Conductivity; D004926:Escherichia coli / Q000187:drug effects*; D005658:Fungi / Q000187:drug effects; D008087:Listeria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D013501:Surface-Active Agents
keywords: Bacteria; Biocides; Cationic surfactants; Surfactant head group; Toxicity; Yeasts