Antimicrobial Characteristics of Untreated Wood: Towards a Hygienic Environment

Abstract

Wood, as a contact surface, has been used for centuries but is usually questioned because of its porosity and organic composition. It has natural antimicrobial properties and, hygienically, can stand the comparison with other materials such as plastic, glass and steel. In this review, we focused on potential microbe-inhibiting properties of wooden surfaces being used in hygienically important places like health institutes and food industries. This article addresses the questionable properties of untreated wood like hygroscopicity, porosity, roughness and chemical composition, and their relation to the hygienic and antimicrobial nature of this material. The other factors linked to the hygienic properties of wood, such as age, species and type of wood, have also been discussed. Our analysis of literature will create better understanding for acceptance of wood as a safety renewable resource. It also provides an outline for future research considering wood material in critical healthcare or food industries.

Experimental Parameters Influence the Observed Antimicrobial Response of Oak Wood (Quercus petraea)

“…This difference could be attributed to the difference in cell wall types of S. aureus (Gram-positive) and A. baumannii (Gram-negative) bacteria. This reason is more likely because the mechanism of action of most of the wood antimicrobial compounds, including flavonoids, tannins, aldehydes, phenolic acids, terpenoids, alkaloids, and terpenes, is to damage the cell wall of bacteria [ 9 ].…”

“…Therefore, they can be considered for applications in hygienically important places, such as in the food industry as food preparation, fermentation, and packaging material, in the livestock sector for animal bedding, and for the indoor construction of residential buildings including healthcare institutes [ 4 , 5 , 6 , 7 , 8 ]. The antimicrobial characteristics of wood material are attributed to its physical structure and chemical composition, which can create unsuitable survival conditions for different microbes [ 9 ]. As this physiochemical profile differs between wood species, the antimicrobial activity also varies accordingly [ 10 , 11 ].…”

“…For example, some wood extractives contain active antimicrobial compounds, such as tannins and phenolics; however, their presence and distribution vary in different wood species, and even in different parts of the same tree [ 1 , 12 ]. Similarly, the anatomy of the wood species and the way it is cut will alter the characteristics of the exposed surfaces, which in turn, can have an impact on the survival conditions for microbes [ 9 ].…”

“…A range of variables linked to wood could influence its physical and chemical composition, and subsequently, the antimicrobial potential of wood material [ 9 ]. The first factor is the anatomy of a tree which causes the wood within it to have three distinct faces depending on how it is cut: transverse (where the open ends of cells can be seen, known as transversal (radial-tangential, RT); longitudinal tangential (LT) and longitudinal radial (LR).…”

“…The third factor is the condition of wood which, in terms of aging, erosion, tearing, and weathering, can influence the physical structure and chemical composition and, likewise, the antimicrobial potential of this material. The condition of wood can be affected by cleaning and sterilization methods [ 17 ], such as when food preparation boards are sterilized using hot water washing and ultraviolet rays [ 9 , 11 ], even gamma radiations at a dose of 25–50 kGy are used to sterilize the wooden samples in experimental studies [ 3 , 18 ]. The final factor to consider is the cutting of wood using high energy laser beams, which burn the material on contact areas.…”