Department of Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Buesgenweg 4, D-37077, Goettingen, Germany.
Norwegian Institute of Bioeconomy Research (NIBIO), Division of Forest and Forest Resources, Wood Technology, Høgskoleveien 8, 1433, Ås, Norway.
Appl Microbiol Biotechnol. 2020 May;104(9):3781-3795. doi: 10.1007/s00253-020-10479-1. Epub 2020 Mar 6.
Wood in service is sequestering carbon, but it is principally prone to deterioration where different fungi metabolize wood, and carbon dioxide is released back to the atmosphere. A key prerequisite for fungal degradation of wood is the presence of moisture. Conversely, keeping wood dry is the most effective way to protect wood from wood degradation and for long-term binding of carbon. Wood is porous and hygroscopic; it can take up water in liquid and gaseous form, and water is released from wood through evaporation following a given water vapour pressure gradient. During the last decades, the perception of wood-water relationships changed significantly and so did the view on moisture-affected properties of wood. Among the latter is its susceptibility to fungal decay. This paper reviews findings related to wood-water relationships and their role for fungal wood decomposition. These are complex interrelationships not yet fully understood, and current knowledge gaps are therefore identified. Studies with chemically and thermally modified wood are included as examples of fungal wood substrates with altered moisture properties. Quantification and localization of capillary and cell wall water - especially in the over-hygroscopic range - is considered crucial for determining minimum moisture thresholds (MMThr) of wood-decay fungi. The limitations of the various methods and experimental set-ups to investigate wood-water relationships and their role for fungal decay are manifold. Hence, combining techniques from wood science, mycology, biotechnology and advanced analytics is expected to provide new insights and eventually a breakthrough in understanding the intricate balance between fungal decay and wood-water relations. KEY POINTS: • Susceptibility to wood-decay fungi is closely linked to their physiological needs. • Content, state and distribution of moisture in wood are keys for fungal activity. • Quantification and localization of capillary and cell wall water in wood is needed. • New methodological approaches are expected to provide new insights.
木材在使用过程中会固定碳，但主要容易受到不同真菌代谢木材的影响，二氧化碳会被释放回大气中。真菌降解木材的一个关键前提条件是存在水分。相反，保持木材干燥是防止木材降解和长期固定碳的最有效方法。木材具有多孔性和吸湿性；它可以吸收液态和气态的水分，并且水分会在一定的水蒸气压力梯度下通过蒸发从木材中释放出来。在过去的几十年中，人们对木材-水分关系的认识发生了重大变化，对受水分影响的木材性质的看法也发生了变化。其中包括木材对真菌腐烂的易感性。本文综述了与木材-水分关系及其在真菌木材分解中的作用相关的研究结果。这些是复杂的相互关系，尚未完全理解，因此确定了当前的知识差距。化学和热改性木材的研究被包括在内，作为具有改变的水分特性的真菌木材基质的例子。特别是在过湿范围，对细胞壁和细胞壁水分的定量和定位被认为是确定木材腐朽真菌最小水分阈值（MMThr）的关键。调查木材-水分关系及其对真菌腐烂作用的各种方法和实验装置存在多种局限性。因此，结合木材科学、真菌学、生物技术和先进分析技术有望提供新的见解，并最终在理解真菌腐烂和木材-水分关系之间的复杂平衡方面取得突破。 关键点： • 对腐朽真菌的易感性与它们的生理需求密切相关。 • 木材中水分的含量、状态和分布是真菌活动的关键。 • 需要对木材中的毛细管和细胞壁水分进行定量和定位。 • 预计新的方法方法将提供新的见解。
