Evaluation of antimicrobial properties of cork

• Published in: FEMS microbiology letters Vol. 363; no. 3; p. fnv231
• Main Authors: Gonçalves, Filipa, Correia, Patrícia, Silva, Susana P., Almeida-Aguiar, Cristina
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-02-2016
• Subjects: Acetic acid; Anti-Infective Agents - isolation & purification; Anti-Infective Agents - pharmacology; Antibacterial activity; Antimicrobial assay; Ciências Biológicas; Ciências Naturais; Copolymers; Cork; cork sterilization; cork water extract; E coli; Escherichia coli - drug effects; Escherichia coli - physiology; Ethylene vinyl acetates; Evaluation; Industrial applications; Microbial Sensitivity Tests; Microbial Viability - drug effects; Microbiology; Minimum inhibitory concentration; natural material; Optimization; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Properties (attributes); Quercus - chemistry; Reduction; Science & Technology; Staphylococcus aureus - drug effects; Staphylococcus aureus - physiology; Time Factors; Vinyl acetate; antibacterial activity; cork sterilization; cork; antimicrobial assay; cork water extract; natural material
• ISSN: 1574-6968; 0378-1097; 1574-6968
• DOI: 10.1093/femsle/fnv231

Cork presents a range of diverse and versatile properties making this material suitable for several and extremely diverse industrial applications. Despite the wide uses of cork, its antimicrobial properties and potential applications have deserved little attention from industry and the scientific community. Thus, the main purpose of this work was the evaluation of the antibacterial properties of cork, by comparison with commercially available antimicrobial materials (Ethylene-Vinyl Acetate copolymer and a currently used antimicrobial commercial additive (ACA)), following the previous development and optimization of a method for such antimicrobial assay. The AATCC 100-2004 standard method, a quantitative procedure developed for the assessment of antimicrobial properties in textile materials, was used as reference and optimized to assess cork antibacterial activity. Cork displayed high antibacterial activity against Staphylococcus aureus, with a bacterial reduction of almost 100% (96.93%) after 90 minutes of incubation, similar to the one obtained with ACA. A more reduced but time-constant antibacterial action was observed against Escherichia coli (36% reduction of the initial number of bacterial colonies). To complement this study, antibacterial activity was further evaluated for a water extract of cork and an MIC of 6 mg mL−1 was obtained against the reference strain S. aureus.
Portuguese cork display antibacterial activity against Gram-positive and Gram-negative bacteria, making this material suitable for several and extremely diverse industrial applications.