Wood as an ecological niche for microorganisms: Wood formation, structure, and cell wall composition

Abstract Besides traditional applications wood is being increasingly used as replacement for fossil-based products. Due to its storage capacity for CO2, wood will also greatly contribute to a reduction of greenhouse gases in the atmosphere. Therefore wood experiences new attractiveness as a highly valuable and environmentally friendly natural resource. Apart from these outlined beneficials, wood tissues also serve as crucial niches for inhabitation by diverse microbiomes, i.e., fungi and bacteria. The current paper deals with the description of wood formation through the cambium as the meristematic tissue responsible for producing new wood cells. Formation and subsequent differentiation of wood cells are the basic processes leading to the development of wood tissues, which are generally divided into soft- and hardwoods. The principles of wood anatomy are laid down based on features revealed by light and electron microscopy. Additionally, characteristics of wood cell walls as the structures determining wood properties are presented on the ultrastructural level. Information is also presented on cell wall composition and interactions between the chemical constituents occurring during the establishment of cell wall architecture. These structural and chemical features of wood ultimately have an impact on the nature and types of microbes that colonize it.