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

耐紫外线真菌对木材染色的解释、开发与控制 在许多户外用途中，木材正在被大规模取代，因为它会被紫外线辐射迅速降解，然后被深色染色真菌滋生，这给木材带来了一种不吸引人的斑点灰色外观。限制这种真菌染色变得更加困难，因为许多能够控制染色真菌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。一种很有希望的方法是通过对真菌染色来干扰黑色素的合成。染色真菌使用黑色素来保护自己免受紫外线辐射的影响，紫外线辐射照射到户外使用的木材表面。我们已经证明，用于控制水稻真菌病害的极低浓度(Ppm)的农用化学品可以通过两种寄生在木材上的有色真菌来抑制黑色素的合成。在纯培养中以这种方式定位的真菌降低了黑色素水平，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一有前景的方法，并构建适用于木材处理的健壮系统。我们还将探索其他控制木材表面真菌染色的新方法，包括：(A)使用红色或浅黄色真菌菌株作为生物控制剂；(B)使用钛或氧化锌纳米颗粒(量子点)作为光催化控制剂。这两种控制木材表面染色的新方法都将在基础研究之前进行，这些基础研究将使用最先进的CFI仪器细致地探索表面真菌和光催化纳米颗粒对木材表面微结构和物理和化学性质的影响。我们的研究专门针对木材，但它也更广泛地与掠夺其他建筑材料的生物膜的控制有关。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，即仅在美国，微生物引起的混凝土腐蚀造成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 fungi Wood 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.