Antimicrobial Effect of Lotus-Type Porous Copper

Abstract

Copper is a superior antibacterial metal, which is used for various antibacterial products. It is known that the antimicrobial property is generated by direct contact of bacterial cell to the copper surface. Since porous copper has a benefit to increase the surface area contacted to atmospheric medium, it is expected that antibacterial effect can be enhanced. Two kinds of lotus-type porous copper with different directional open pores were used as samples. In order to elucidate such enhancement, four kinds of culture tests on porous copper plates were carried out using bacteria of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella enteritidis. While the counts of viable bacteria of Staphylococcus aureus and Escherichia coli cultured on non-porous copper do not change significantly, the counts of Pseudomonas aeruginosa and Salmonella enteritidis decreases. The counts of the viable bacteria of Staphylococcus aureus and Escherichia coli cultured on porous copper drastically decrease, while the counts of Salmonella enteritidis decreases to some degree. However, the porosity does not affect the decrease of counts of Pseudomonas aeruginosa. Thus, apparent antibacterial property of porous copper is attributed to increase of contact area of the bacteria to porous copper for Staphylococcus aureus, Escherichia coli and Salmonella enteritidis.