Explaining, exploiting and controlling the staining of wood by UV tolerant fungi

解释、利用和控制耐紫外线真菌对木材的染色木材在许多户外用途中被大规模取代，因为木材在紫外线辐射下会迅速降解，然后被深色染色真菌占据，这使得木材呈现出不吸引人的斑驳灰色外观。限制这种真菌染色变得更加困难，因为许多能够控制真菌染色的杀菌剂已经不再可用，它们的替代品也不那么有效。因此，需要通过真菌染色来控制木材变色的新方法。一种显示出希望的方法是通过染色真菌来破坏黑色素的合成。染色真菌使用黑色素来保护自己免受户外使用的木材表面的紫外线辐射。我们已经证明，用于控制水稻真菌病的非常低浓度（ppm）的农业化学品可以抑制寄生在木材上的两种染色真菌的黑色素合成。在纯培养中，以这种方式定位的真菌黑色素水平降低，并且在阳光的紫外线成分存在下无法生长。该项目将进一步探索这种有前途的方法，并构建适用于木材处理的强大系统。我们还将探索控制木材表面真菌染色的其他新方法，包括：(a)使用红色或浅黄色真菌菌株作为生物防治剂；(b)使用钛或氧化锌纳米粒子（量子点）作为光催化控制剂。在这两种控制木材表面染色的新方法之前，将进行基础研究，这些研究将使用最先进的CFI仪器详细探测表面真菌和光催化纳米颗粒对木材表面微观结构和物理化学性质的影响。我们的研究专门针对木材，但它也更广泛地与控制破坏其他建筑材料的生物膜有关。这个问题的规模是巨大的，可以参考最近的一项估计来衡量，仅在美国，微生物引起的混凝土腐蚀的经济影响每年就超过1000亿美元。

Explaining, exploiting and controlling the staining of wood by UV tolerant fungiWood is being replaced on a large scale for many outdoor uses because it is rapidly degraded by UV radiation and then colonized by dark-coloured staining fungi, which give the wood an unattractive blotchy-grey appearance. Restricting such fungal staining is becoming far more difficult because many of the fungicides that were able to control staining fungi are no longer available, and their replacements are less effective. Hence, new approaches to controlling the discolouration of wood by staining fungi are needed. One approach that is showing promise is to disrupt the synthesis of melanin by staining fungi. Staining fungi use melanin to protect themselves from the UV radiation that is incident at the surface of wood used outdoors. We have shown that very low concentrations (ppm) of agricultural chemicals that are used to control a fungal disease of rice can inhibit the synthesis of melanin by two staining fungi that colonise wood. Fungi targeted in this way in pure culture had reduced levels of melanin and failed to grow in the presence of the UV component of sunlight. This project will explore this promising approach further and construct robust systems suitable as wood treatments. We will also explore other novel approaches for controlling fungal staining of wood surfaces including: (a) Use of red or buff coloured strains of fungi as biocontrol agents and; (b) Use of titanium or zinc oxide nanoparticles (quantum dots) as photocatalytic control agents. Both these new approaches to controlling the staining of wood surfaces will be preceded by fundamental research that will probe in exquisite detail using state-of-the-art CFI instrumentation the effects of surface fungi and photo-catalytic nanoparticles on the micro-structure and physical and chemical properties of wood surfaces. Our research specifically targets wood, but it is also more broadly relevant to the control of biofilms that despoil other building materials. The scale of this problem is immense and can be gauged with reference to a recent estimate that the economic impact of microbial-induced corrosion of concrete in the USA alone exceeds $100 billion per annum.