Wood decay under the microscope

Many aspects of the interactions between host wood structure and fungal activity can be revealed by high resolution light microscopy, and this technique has provided much of the information discussed here. A wide range of different types of decay can result from permutations of host species, fungal species and conditions within wood. Within this spectrum, three main types are commonly recognised: brown rot, white rot and soft rot. The present review explores parts of the range of variation that each of these encompasses and emphasizes that degradation modes appear to reflect a co-evolutionary adaptation of decay fungi to different wood species or the lignin composition within more primitive and advanced wood cell types. One objective of this review is to provide evidence that the terms brown rot, white rot and soft rot may not be obsolete, but rigid definitions for fungi that are placed into these categories may be less appropriate than thought previously. Detailed knowledge of decomposition processes does not only aid prognosis of decay development in living trees for hazard assessment but also allows the identification of wood decay fungi that can be used for biotechnology processes in the wood industry. In contrast to bacteria or commercial enzymes, hyphae can completely ramify through solid wood. In this review evidence is provided that wood decay fungi can effectively induce permeability changes in gymnospermous heartwood or can be applied to facilitate the identification of tree rings in diffuse porous wood of angiosperms. The specificity of their enzymes and the mild conditions under which degradation proceeds is partly detrimental for trees, but also make wood decay fungi potentially efficient biotechnological tools.     

威海地区547例甲真菌病真菌培养结果分析

目的了解山东省威海地区甲真菌病的临床分类、菌种构成等流行情况。方法对547例镜检阳性的甲真菌病患者进行真菌培养、鉴定和临床分析。结果547例患者中真菌培养阳性423例,阳性率77.3%,远端侧位甲下型甲真菌病(DLSO)295例(53.9%),白色浅表型甲真菌病(SWO)36例(6.5%),近端侧位甲下型甲真菌病(PSO)78例(14.2%),全甲营养不良型甲真菌病(TDO)138例(25.2%)。共分离出429株真菌,其中皮肤癣菌354株(82.5%),酵母菌61株(14.2%),非皮肤癣菌霉菌14株(3.3%)。结论山东省威海地区甲真菌病病原体的分布以皮肤癣菌为主,其次为酵母菌和非皮肤癣菌霉菌,红色毛癣菌是最常见的皮肤癣菌,临床类型以DLSO型居多,其他依次是TDO、PSO、SWO。就诊人群中以20～50岁年龄段为最多见。     

Lithocarols A-F,six tenellone derivatives from the deep-sea derived fungus Phomopsis lithocarpus FS508

Lithocarols A-F (1–6) possessing novel highly-oxygenated isobenzofuran core, together with a related known compound isoprenylisobenzofuran A (7) were isolated from the marine-derived fungus Phomopsis lithocarpus FS508. Among them, lithocarols A-E (1–5) represent the first examples of poly-ketal derivatives in tenellone family. The structures for all these compounds were fully elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculations. Their cytotoxic assay disclosed that compounds 1–4 displayed moderate growth inhibitory effect against four human tumor cell lines with the IC₅₀ values ranging from 10.5 to 38.7 μM.     

中国疱衣属地衣的初步研究

报道了中国疱衣科疱衣属一新记录种：类喜马拉雅疱衣(Phlyctis subhimalayensis S. Joshi&Upreti),提供了该种的形态特征描述和DNA数据支撑。还对中国已知的疱衣属物种进行了简要描述。同时讨论了近似种,编制了分种检索表,为疱衣属的进一步研究提供了基础资料。     

Studies of Aquatic Fungi. XIII. Mycoflora of the River Czarna Hańcza and its Tributary,the River Marycha

The authors investigated the mycoflora and the environmental factors in the River Czarna Hańcza (10 stations) and its tributary River Marycha (1 station) as well as Lakes Hańcza (2 stations) and Wigry (2 stations) on the occurrence of various aquatic fungi. At the stations investigated the presence of 45 aquatic fungi species was noted. The following fungi, up to now unknown in Poland, were found: Monoblepharis hypogyna, Rozellopsis inflata, Cladolegnia eccentrica, Apostemidium guernisaci, Anguillospora gigantea, Geniculospora grandis, Clavariopsis aquatica, Lemonniera aquatica and Lemonniera terrestris.     

Purification and characteristics of cytosolic chitinase from Piromyces communis OTS1

Abstract A chitinase was purified from the cytosolic fraction of the anaerobic rumen fungus Piromyces communis OTS1 by affinity chromatography using regenerated chitin, gel filtration and chromatofocusing. The chitinase was most active at pH 6.2 and at 60 °C in a 20-min assay. The molecular mass of the purified protein was estimated by SDS-PAGE to be 42 kDa and its pI was 4.9. The enzyme activity, which was of the 'endo' type, was inhibited by A⁺, Hg²⁺ and allosamidin. N -Acetyl- β -glucosaminidase and 'exo' type chitinase activity were absent from the purified preparation.     

Purification and characterization of an extracellular polygalacturonase from the thermophilic fungus,Thermomyces lanuginosus

A polygalacturonase was purified from the thermophilic fungus, Thermomyces lanuginosus to apparent homogeneity by ultrafiltration, acetone precipitation and ion-exchange chromatography. The enzyme was maximally active at pH 5.5 and 60 °C. The apparent K_M with potassium pectate was 0.67 mg/ml and the V_max was 7.2 × 10⁵ mol/min/mg protein. The apparent molecular weight of the enzyme was 59 kDa and it contained approximately 10% carbohydrate. The enzyme was completely stable at room temperature (32 ± 3 °C) and retained about 50% activity at 50 °C for 6 h. The zymogram of the purified enzyme revealed two activity bands, one of which was a major one. Polyclonal antibodies raised against the enzyme did not show any immunological relatedness with other mesophilic polygalacturonases.