6种白腐菌腐朽前后的山杨木材酚酸种类和含量变化的高效液相色谱分析

研究阔叶树上的6种木材白腐菌火木层孔菌、粗毛盖菌、偏肿拟栓菌、三色革裥菌、冬拟多孔菌和血红密孔菌对山杨材腐朽前后木材中游离酚酸种类和含量的变化情况.结果表明:受6种白腐菌腐朽后的山杨木材中酚酸的种类和含量各不相同,在山杨材被分解120 d后,偏肿拟栓菌、三色革裥菌、血红密孔菌和冬拟多孔菌的9种游离酚酸总含量远大于粗毛盖菌和火木层孔菌的9种游离酚酸总含量,表明前4种对木质素分解能力较强的菌种获得了较高含量的酚酸;但从9种游离酚酸总的含量上看,与各菌种对木材和木质素的分解百分率不尽相同,初步分析的原因表明在木质素被分解的过程中除了有这9种游离酚酸产生以外,可能还会产生其他的游离酚酸以及苯环二聚体、三聚体和各种寡聚体以及杂环的形式,所有这些苯环结构总体造成了对木质素分解百分率的差异. 对9种酚酸进行分析测试,只构成对木质素分解的一部分,不足以用来解释对木质素的全部分解能力,其他的酚酸和游离酚酸以外的苯环结构还有待进一步研究分析测试;从各种游离酚酸单个含量上看,各种白腐菌的种类和含量都各不相同,表明不同白腐菌对同一木质纤维基质的分解途径、中间降解产物各不相同.另外,未腐朽的木材中本身就含有一些微量的酚酸成分,这些酚酸在生物分解过程中会降解和转化成其他成分, 是否有可能转化成其他种类的酚酸还有待进一步证明.     

木材真菌染色研究现状及发展趋势

木材真菌染色是由于真菌侵染而导致材色改变,包括菌纹线、白腐和染色。木材真菌染色可形成特殊肌理和色泽,改善木材的装饰特性,为木质产品的设计带来多样化的塑造空间。作为一种全新、天然的染色方式,真菌染色技术对于木材的美学价值和综合利用率都有较大提高。目前,分析木材真菌染色机理及染色工艺改进是开发真菌染色木材的关键。菌纹线是由于真菌的种间或种内的对抗形成,染色是由于真菌在细胞外部分泌色素或是伴随真菌自身在木材内部的生长形成。笔者从木材真菌染色机理、染色方法、染色条件、真菌染色木材性能等方面综述了木材真菌染色的研究进展。重点介绍了针对不同表现形式的不同染色方法,并对存在的问题进行了分析,提出了后续研究的方向为采用多种真菌的组合运用、环保色素溶剂的筛选、探寻更多的真菌色相用于色素提取方法染色、结合染料渗透机理改进染色工艺等。     

木材白腐菌对木质素生物降解机制的初步研究

通过测定6种白腐菌火木层孔菌Phellinus igniarius及粗毛盖菌Funalia gallica、三色革裥菌Lenzites tricolor、冬拟多孔菌Polyporellus brumalis、偏肿拟栓菌Pseudotrametes gibbosa和血红密孔菌Pycnoporus sanguineus分解山杨材一定时间后的木质素含量，研究木材白腐菌对山杨材木质素生物降解机制。测定结果表明，按照木质素的减少百分率，这6种白腐菌对山杨材木质素的分解能力依次为血红密孔菌、偏肿拟栓菌、三色革裥菌、冬拟多孔菌、冬拟多孔菌、火木层孔菌；6种白腐菌对山杨材木质素及综纤维素的分解量X1、X2及分解时间Y这3个量之间存在多元回归关系；冬拟多孔菌是较多分解木质素、较少分解纤维素的木材白腐菌。     

Automated quantification of the impact of the wood-decay fungus Physisporinus vitreus on the cell wall structure of Norway spruce by tomographic microscopy

The visualization and the quantification of microscopic decay patterns are important for the study of the impact of wood-decay fungi in general, as well as for wood-decay fungi and microorganisms with possible applications in biotechnology. In the present work, a method was developed for the automated localization and quantification of microscopic cell wall elements (CWE) of Norway spruce wood such as bordered pits, intrinsic defects, hyphae or alterations induced by white-rot fungus Physisporinus vitreus using high-resolution X-ray computed tomographic microscopy. In addition to classical destructive wood anatomical methods such as light or laser scanning microscopy, this method allows for the first time to compute the properties (e.g., area, orientation and size distribution) of CWE of the tracheids in a sample. This is essential for modeling the influence of microscopic CWE on macroscopic properties such as wood strength and permeability.     

Mycologg: a new accelerated test method for wood durability above ground

If not properly handled, selected and protected, wood will be degraded by bacteria, fungi and also insects. In order to ensure service life, durability tests are needed. Most accelerated laboratory tests on wood durability are focused either on fungi attacks or the uptake of moisture. Accelerated field tests in ground contact are of limited use since they could be difficult to reproduce and are sensitive to the characteristics of the soil in which the wood is placed. In addition, the results cannot be directly transferred to wood in use above ground because such wood is subjected to different set of conditions. The Mycologg is a new accelerated test method for estimating the durability of wood in above ground applications. The Mycologg allows the test panels to be subjected to the discolouring fungi and different RH (relative humidity) cycles simultaneously. Every 30 min, the temperature, the RH, and the moisture content in each test panel are measured and saved in special software. This allows for a constant update of the moisture patterns during a fungi attack. A trial was made with Scots pine (Pinus sylvestris) heartwood samples, where fungal growth after 6, 8 and 10 weeks in the Mycologg were compared to weather exposure of duplicate samples after 12, 16, and 26 months. The results showed that 10 weeks into the Mycologg accelerated test method corresponds well to real-time weather exposure with respect to fungal discolouration.     

Erfahrungen über die Auswirkungen längerer Wasserlagerung auf die Qualität von Nadelstammholz

Summary Unbarked windthrown softwood timber was stored in water for about two years and during that time the protection effect against storage decay has been tested at certain intervals. The moisture content of the seperately swimming logs did not change remarkably in the interior of the stems, only from their ends some water has diffused into the wood. Apart from a small light red-brown discolouration in consequence of the penetration of tannin from the bark into the wood, which has no economical effect, in all these logs not any injuries caused by fungi, insects or cracks could be observed. When the logs are piled in more layers, the stems of the upper layers dried faster and showed all the wellknown storage damages. Provided that timber is sawn soon after the landing, water storage can be considered as an effective mean to prevent degradation during storage, but if sawing is retarded, the wood will be attacked by insects and fungi as well as the stems stored in forests after felling.      

Acetic acid fermentability with <Emphasis Type="Italic">Clostridium thermoaceticum</Emphasis> and <Emphasis Type="Italic">Clostridium thermocellum</Emphasis> of standard compounds found in beech wood as produced in hot-compressed water

Acetic acid fermentability of various compounds from beech wood as produced in a two-step hot-compressed water treatment was evaluated by fermentation tests using standard compounds with Clostridium thermoaceticum and Clostridium thermocellum. For cellulose- and hemicellulose-derived products, the former microorganism was found to ferment compounds with low molecular weights such as monosaccharides, decomposed products, and organic acids to acetic acid, while the latter was found to ferment compounds with high molecular weights such as polysaccharides and oligosaccharides to acetic acid. Lignin-derived products were, on the other hand, fermented by both microorganisms to acetic acid. Based on these lines of evidence, co-culture with C. thermoaceticum and C. thermocellum was evaluated and proven to increase acetic acid fermentability. Consequently, almost all compounds produced from beech wood in hot-compressed water were found to be converted to acetic acid when using these microorganisms in combination. Thus, hot-compressed water treatment coupled with acetic acid fermentation would likely be a powerful method to produce acetic acid from lignocellulosics.     

Factors affecting the fungal colonization of pine lumber

This study investigated whether the physiological condition of wood influenced patterns of colonization by mould and sapstain fungi. The extent of fungal defacement on sawn pine lumber Pinus nigra var. maritima that had been killed by gamma‐irradiation was compared with the defacement on untreated, still living timber that had been aged for up to 16 weeks prior to being sawn. All the sawn lumber was exposed to the natural inoculum of sapstain and mould fungi in a working sawmill environment over a 4‐week period. The results indicated that the pattern of fungal defacement differed markedly in dead or aged wood compared with untreated wood. Mould fungi were most prevalent on the dead irradiated wood, whereas sapstain fungi dominated the freshly sawn lumber which was still living. The differences appear to be independent of wood moisture content and may be related to the production of inhibitory compounds by living cells in wood as it becomes senescent and dies.     

食用菌原料林的营造及其利用的探讨

采取人工营造速生的木生食用菌适生树种,定向培育食用菌原料林,短期轮伐利用,使林菌生产有机地结合起来,实现以林养菌、以菌促林的良性循环,从根本上解决林菌之间的矛盾。     

杉木林地土壤微生物研究进展

杉木是我国主要造林树种之一,具有生长快、产量高、材质好的优点。土壤微生物与杉木林地土壤理化性质、土壤肥力以及植物根系之间有密切的关联。文中概述了不同林分条件下杉木林地土壤微生物的群落特征及其与土壤质量之间的响应机制,尤其是与植物根系共生关系方面的研究进展,以期为实现杉木林质量的精准提升提供理论参考。天然林和阔叶林较杉木人工林有更丰富的微生物群落,在杉木林生长发育过程中,中龄阶段各微生物指标最低。杉木林土壤微生物群落组成、生物量和活性等均与土壤酸碱性、通气状况、养分含量等存在密切的响应关系。杉木林菌根真菌主要属于球囊霉属,国内对杉木林下菌根真菌的研究仍处于初级阶段。未来土壤微生物的研究热点包括土壤微生物的时空演变规律、土壤微生物在提升土壤肥力上的机理和途径、菌根真菌在土壤养分高效利用中的机制等。     

6种木材白腐菌对山杨材木质素分解能力的研究

由于不同的木材腐朽菌的生理特性不同 ,所分泌的酶及酶的活性各不相同 ,因此 ,不同的腐朽菌分解木材的各种成分及相对速度就各不相同 ,而且对于木质纤维基质会有不同的中间代谢产物。本项研究选择了火木层孔菌 (Phelliusigniarius)及另外 5种木材分解能力较强的阔叶树上的白腐菌 :粗毛盖菌 (Funaliagallica)、三色革裥菌 (Lenzitestricolor)、冬拟多孔菌 (Polyporellusbrumalis)、偏肿拟栓菌 (Pseudotrametesgibbosa)和血红密孔菌 (Pyc noporussanguineus) ,研究了它们对山杨木材木质素的分解能力 ,测定了经 6种白腐菌分解一定时期的山杨木材木质素的含量 ,作为木材白腐菌对山杨木材木质素生物降解机制的初步研究 ,旨在为山杨木材生物制浆造纸提供应用基础理论研究 ,同时也可为木质素合理的生物转化为有用的化学品、生物漂白、酶处理防止机械浆的返黄、废水治理、纤维素酶解糖化的微生物前处理等提供相关的借鉴研究 ,以期在生产实践中减轻环境污染并充分利用木质素资源。在无菌的条件下 ,将山杨木片样品分别放入以上 6种白腐菌的平板培养基中受菌侵染 ,一定时间后取出 ,去除木片表面的菌丝体 ,然后分别测定未腐朽材和受菌侵染 4 0d、6 0d、80d和 12 0d时木片样品中木质素的含量 ,分析 6种白腐菌对山杨木     

6种白腐菌腐朽后的山杨木材和木质素官能团变化的红外光谱分析

选择火木层孔菌及 5种木材降解能力较强的阔叶树上的白腐菌 :粗毛盖菌、偏肿拟栓菌、三色革裥菌、冬拟多孔菌和血红密孔菌 ,采用国内外红外光谱分析的标准方法 ,用傅里叶红外光谱仪测定未腐朽材木粉和受 6种白腐菌腐朽 12 0d后的腐朽材木粉试样的红外光谱图。刮取未腐朽的山杨木材样品和受 6种白腐菌腐朽 12 0d时的山杨木材样品表层少许 ,在干燥条件下 ,分别放入KBr中 ,磨细 ,压片 ,然后在FTIR光谱仪上进行测定 ,得到经 6种白腐菌降解 12 0d后的木材木粉和未腐朽材木粉其木材和木质素官能团谱峰位置和谱峰相对吸收强度的振动变化状况 ,进而分析腐朽后的山杨木材和木质素官能团的变化情况 ,以作为木材白腐菌对山杨材生物降解机制的进一步研究。结果表明 ,受 6种白腐菌腐朽后的山杨木材和木质素官能团都受到一定程度的降解 ,但各自的变化情况有所不同。对木质素的降解主要是存在于侧链上 ,虽然苯环骨架变化不明显 ,但木质素苯环间的羰基、CH2 结构、紫丁香基和愈疮木基等侧链已部分被降解。从各吸收峰相对吸收强度的变化大小来看 ,血红密孔菌、冬拟多孔菌、三色革裥菌和偏肿拟栓菌对木质素降解的程度大于粗毛盖菌和火木层孔菌对木质素降解的程度     

Fungal–copper interactions in wood examined with large field of view synchrotron-based X-ray fluorescence microscopy

ABSTRACT

The goal of this study was to demonstrate how synchrotron-based X-ray fluorescence microscopy (XFM) can be used to better understand the mechanisms of copper tolerance in wood decay fungi. Copper is a major component in commercial wood preservatives as it is toxic to many wood decay fungi. However, certain fungi are copper tolerant and can attack preservative-treated wood, resulting in structural damage to treated wood members. Here we used large-field XFM to visualize six different elements (K, Ca, Mn, Fe, Cu, and Zn) in the mycelia and wood inoculated with four different species of brown rot wood decay fungi. Wood blocks were partially dipped into a solution of copper sulfate, exposed to fungi in malt extract agar petri dish assays for nine weeks, and then imaged and compared to blocks that were partially dipped in water. The blocks were imaged immediately adjacent to an end-matched control that was placed in malt extract agar petri dish assays for 9 weeks, but not exposed to the fungi so that the differences in the elemental distributions could be directly compared. The colonized wood and mycelia were rich in K, Ca, Mn, and Fe; however, the elements and the spatial distribution in the mycelia and wood differed across fungal species. The most interesting results were the maps showing the copper distribution. While three of the four fungi grew on the copper-rich region of the wood, only one species, Fibroporia radiculosa, dramatically reduced the copper concentration in the region of fungal growth.     

Biodegradation of new quaternary ammonium compounds in treated wood by mould fungi

The degradation of seven potential wood preservatives based on imidazolium compounds (ICs) and quaternary ammonium compounds (QACs) with a modified anion structure by mould fungi was determined using soil-block method. Experiments were carried out on Scots pine (Pinus sylvestris L.) wood. Two-phase titration and high-performance liquid chromatography (HPLC) method were used to detect and quantify the degradation products. The performed soil-block tests showed that the ICs and QACs with alkoxymethyl substituents were leached from the experimental wood when in contact with moist soil and revealed their fungal detoxification by mould fungi, especially by Gliocladium roseum. The degree of biological decomposition of new compounds was higher than didecyldimethylammonium chloride and didecylmethylpoli(oxyethyl)ammonium propionate. The observations of the colonization by mould fungi were made using the scanning electron microscope (SEM). Decay of treated wood by mould fungi showed its tolerance to QACs.     

Effect of heat treatment intensity on some conferred properties of different European softwood and hardwood species

Effect of heat treatment intensity on some conferred properties like elemental composition, durability, anti-swelling efficiency (ASE) and equilibrium moisture content (EMC) of different European softwood and hardwood species subjected to mild pyrolysis at 230 °C under nitrogen for different durations has been investigated. Independently of the wood species studied, elemental composition is strongly correlated with the mass losses due to thermal degradations which are directly connected to treatment intensity (duration). In all cases, an important increase in the carbon content associated with a decrease in the oxygen content was observed. Heat-treated specimens were exposed to several brown rot fungi, and the weight losses due to fungal degradation were determined after 16 weeks, while effect of wood extractives before and after thermal treatment was investigated on mycelium growth. ASE and EMC were also evaluated. Results indicated important correlations between treatment intensity and all of the wood conferred properties like its elemental composition, durability, ASE or EMC. These results clearly indicated that chemical modifications of wood cell wall polymers are directly responsible for wood decay durability improvement, but also for its improved dimensional stability as well as its reduced capability for water adsorption. All these modifications of wood properties appeared simultaneously and progressively with the increase in treatment intensity depending on treatment duration. At the same time, effect of extractives generated during thermal treatment on Poria placenta growth indicated that these latter ones have no beneficial effect on wood durability.     

Molecular identification of decay fungi in the wood of urban trees

Trees are valuable for urban areas, however, are also susceptible to wood rot fungi. For accurate and fast assessment of the severity and evolution of decay in standing trees, a molecular technique was used to identify the causal agents of wood rot. Fruit bodies of wood decay fungi were collected from infected trees in various stands in Germany. Thirty-six species were identified by traditional methods. The DNA of fruit bodies was extracted, ITS-rDNA amplified by PCR, and ITS regions sequenced. Wood samples from infected urban trees were collected, the entire DNA extracted from affected wood parts, and fungal ITS amplified and sequenced. Fungal species were identified by comparing sequence data with the fruit body data. The technique enables an accurate and rapid identification of causal rot fungi in urban trees.     

Diversity and community structure of wood-inhabiting fungi found in Japanese wooden houses analyzed by the next-generation sequencing

The diversity and community structures of wood-inhabiting fungi in 16 decayed wood samples from ten wooden houses in Japan were analyzed using a next-generation sequencing (NGS) to determine the fungi responsible for wood decay. DNA of fungi in decayed wood was extracted directly, the internal transcribed spacer (ITS) region in ribosomal DNA (rDNA) was amplified by polymerase chain reaction (PCR), and then, sequences of tagged ITS fragments were analyzed by NGS. Results of sequencing indicated that 68 species of ascomycetes, 37 species of basidiomycetes, and one fungus each from Mortierellales and Mucoromycetes were detected. The fungal community structures showed diversity and included various species of ascomycetes. A microscopic examination of cell wall structure in decayed wood samples suggested that some ascomycetes were soft-rot fungi. Heat map analysis indicated that the similarity in the structures of fungal communities was influenced to a greater extent by the wood species of samples than where they were used as a component.     

我国南方食用菌原料林培育研究进展

香菇等食用菌在我国具有近千年的栽培历史，是山区经济发展的重要产业，食用菌原料林的培育对于以阔叶权赤原食用菌产业持续发展意义重大。本文重点对食用菌原料林树种的优选、人促更新定向培育、主要原料林树种的丰产栽培以及其采种基地建设等进行述评。根据食用菌原料林培育研究现状和存在问题，提出进一步发展的技术对策和今后的研究重点，包括主要原料树树的种的良种选育和扩繁技术、育苗技术、松杉林冠下造林技术和多种食用菌原料林树种混植技术、二代食用菌原料林的萌芽更新技术等。     

The formation of dry zones in the sapwood of conifers II. The role of living cells in the release of water

Dry zones in conifer wood, characterised by gas filled tracheids, were induced by the injection of dilute solutions of various toxic chemicals followed by incubation at 10 or 20°C. The development of dry zones did not occur at lower temperatures nor with concentrated solutions and was prevented or retarded in an atmosphere of nitrogen. These results are discussed in relation to the development of dry zones in infections by Fomes annosus and other fungi and in the formation of heartwood. It is postulated that the gradual death of ray cells alters their metabolism in such a way that gas emboli are evolved in adjacent tracheids; this can occur at sites of infection or at a distance under the influence of transportable or diffusible toxins.