氧等离子体改性酶解木质素/杨木纤维复合材料热压工艺研究

采用响应面法优化了氧等离子体改性酶解木质素/杨木纤维复合材料的热压工艺参数。结果表明,纤维含水率和热压温度对复合材料的物理力学性能有显著影响。优化后的热压工艺参数范围为:热压温度205～210℃,纤维含水率17%～20%,热压时间63～68 s/mm。     

Genetic parameters of growth and wood quality traits in Picea abies

Genetic parameters were estimated for wood and growth traits in two 19-yr-old clonal trials and a 40-yr-old full-sib progeny trial of Norway spruce [Picea abies (L.) Karst.]. In the clonal trials high (>0.4) broad-sense heritabilities were found for wood density traits, lignin content, number of internal cracks, growth traits, spiral grain and number of resin canals. Moderate (0.2–0.4) heritabilities were found for tracheid lumen diameter and cell wall thickness, microfibril angle and tracheid length, while low heritabilities (<0.2) were found for pulp yield, fibre strength, wood stiffness and wood colour. Lignin content and pulp yield showed low genetic variation, whereas the genotypic coefficient of variation for most other traits ranged between 5 and 15%. Most traits showed low levels of genotype by environment interaction. Among the wood properties, latewood proportion, earlywood density and ring density showed significant, adverse correlations with volume in both clonal trials.     

‘砀山酥梨’褐皮芽变木质素含量及相关酶活性与CCoAOMT 表达量分析

 为了探讨‘砀山酥梨’芽变品系‘锈酥’果皮褐色形成机理,采用分光光度法测定盛花后25、50、75、100、125、150和175 d果皮中木质素含量和相关酶活性变化;从构建的‘锈酥’正向SSH-cDNA文库中筛选出与木质素生物合成密切相关的CCoAOMT-EST,通过实时荧光定量PCR测定了‘砀山酥梨’和‘锈酥’果皮中CCoAOMT的相对表达量。结果表明：‘锈酥’果皮发育前期木质素增量较大,且木质素增量累计比‘砀山酥梨’高12.2%;‘砀山酥梨’和‘锈酥’果皮中PAL、4CL、CAD酶活性均在花后75 d达到最大值,而POD酶活性则在花后125 d出现高峰;二者果皮中4种酶活性变化趋势基本一致,但‘锈酥’果皮中均相对较高;‘锈酥’果皮中的PAL和4CL酶活性与木质素增量变化均呈显著正相关,而‘砀山酥梨’则未呈现出此规律;在果实生长发育各个时期,‘锈酥’果皮中CCoAOMT相对表达量均高于‘砀山酥梨’。因此推测,‘锈酥’果皮褐色形成与果皮中木质素积累及相关酶活性提高有关,果皮中CCoAOMT的增量表达是‘锈酥’果实褐皮形成的重要原因之一。     

Main Anatomy Characteristics in Cell Wall and Lignin Distribution of Bamboo Culms(Pseudosasa amabilis)

The anatomy characteristics of cell wall and lignin distribution in different anatomical regions for 12-month-old bamboo species Pseudosasa amabilis was investigated.The lignin distribution was studied by means of optical microscope and confocal laser scanning microscope and the color reaction. In addition,the distribution of lignin in different tissues(fiber,parenchyma and vessel) was investigated by visible-light microspectrophotometry coupled with the Wiesner and Maule reaction.The cell walls of different tissues were all lignified and the lignin was widely distributed in different tissues, in which there was a difference between tissues and anatomical regions in lignin content.Guaiacyl lignin and syringyl lignin unit could be found in cell wall of fiber,parenchyma and vessel through Wiesner and Maule reaction and the absorbance peak of spectrum. There was no regular variation in lignin content with different radial location of culms and different location in fiber strands.The lamellation of the fiber cell wall was generally had as alternating broad and narrow layers with alternating low and high concentration of lignin.     

木质纤维素乙醇专利分析研究

对世界范围内的木质素乙醇相关专利技术进行了深入分析,包括技术发展趋势分析、技术生命周期分析、申请人分析、国家技术实力分析、关键技术分类分析、同族分析,旨在通过专利分析洞悉木质素乙醇技术的整体发展态势,为本领域的技术创新和决策提供参考。     

Chemical composition of wood and its connection with wood anatomy in Betula pubescens

ABSTRACT

The connection between chemical composition and anatomy of wood is poorly studied. Abiotic and biotic growth conditions affect the synthesis of structural compounds and the anatomy of wood at the same time as they affect growth. In this study, the wood chemical composition, and connections between wood chemistry and anatomy were studied in downy birch (Betula pubescens Ehrh.) grown on four growth sites possessing mineral and peat soils. Lignin, holocellulose, extractive and ash contents, and effective heating value were analysed and compared with libriform fibre double wall thickness and lumen diameter, vessel size and number, and ray and axial parenchyma numbers. Measured lignin and extractive contents were exceptionally high and holocellulose content low. Correlations between wood anatomy and effective heating value were partly different on different soils. Correlations between holocellulose and anatomy were the opposite of the correlations between other chemical compounds and anatomy. The significant correlations between chemical composition and anatomy were commonly opposite in trees grown on peat than in trees grown on mineral soil. Particularly, vessel characteristics and fibre wall thickness correlated significantly with wood chemistry in trees grown on mineral soil. The connections between wood anatomy and chemistry proved to be soil-dependent.     

FDA‐active fungal mycelium and lignin concentrations in some needle and leaf litter types

The concentration of live fungal biomass (FDA mycelium) was investigated in seven chemically very different litter types, i.e. grey alder leaves, green and brown leaves of white birch, green and brown needles of both Scots pine and lodgepole pine. Concentration of FDA mycelium in the litters changed with the season, being low during the dry late summer and relatively higher during the more rainy, wet autumn. During autumns, when moisture was not limiting, lignin concentration and live fungal biomass were negatively related. It was concluded that the concentration of live fungal biomass in litter decreased linearly as the lignin concentration increased and thus also decreased linearly to decomposition level of the litter.     

Decomposition of tree root litter in a climatic transect of coniferous forests in northern Europe: A synthesis

The purpose of this study was to understand the variation in root litter mass‐loss rates in a climatic transect across a large region ranging from the Arctic Circle (66°N) in Scandinavia to Berlin (52°N) in north‐east Germany, dominated by coniferous monocultural forests. To investigate the combined influence of litter quality and climate, data were used from 37 sites and plots at which root litters of three coniferous species (Pinus sylvestris, Pinus contorta and Picea abies) had been incubated. In spite of the considerable climatic differences among sites, there were no strong relationships between any climatic variable and the lst‐yr mass loss (range 17.0–40.9%). For the lst‐yr mass loss, the average annual temperature was the most rate‐regulating factor for all litter combined, with a value for R ² _adj of 0.186. Substrate quality also had an influence. Thus, for the whole region lignin concentration was significant, with a value for R ² _adj of 0.142. For the separated groups of pine and spruce stands the value for r ² increased but the factor average temperature still dominated and for pine the R ² _adj reached a value of 0.346. Over the region N concentration in the fresh pine root litter was significant (R² _adj = 0.232). For the root litter of P. abies the average temperature in July was the strongest rate‐regulating climatic factor, with a value for R ² _adj of 0.381. A combination of temperature in July and the initial P concentration in the litter gave an R ² _adj value of 0.713 for P. abies litter, thus explaining about 71% of the variation.     

施加内生真菌拟茎点霉（Phomopsis sp.）对茅苍术凋落物降解及土壤降解酶活性的影响

通过向盆栽土壤中分别添加茅苍术(Atractylodes lancea (thunb) DC.)凋落物（CK）、内生真菌拟茎点霉（Phomopsis sp. 编号B3）和灭菌凋落物(MB)、内生真菌和凋落物(WB)、内生真菌和凋落物及菌体发酵液(WBF)、凋落物和灭菌发酵液 (WMF) 后,定期检测凋落物纤维素、木质素降解率,测定土壤纤维素酶和木质素酶活性,并利用巢式PCR方法跟踪土壤中活体内生真菌B3动态变化,研究了土壤施加内生真菌对掉落的茅苍术残体的分解及土壤降解酶活性影响。结果表明,植物内生真菌离开宿主进入土壤仍具有生理活性,能适应非宿主环境,存活30d之久。在此期间,内生真菌在富含凋落物的土壤中明显加快纤维素、木质素的降解,在10d、30d、60d取样测定,处理组中WBF和MB的土壤纤维素酶活性显著高于其他处理组,处理组MB和WB的土壤木质素酶活性显著高于其他处理组。     

碳氮源对复合木质素降解菌木质素降解能力及相关酶活的影响

白腐真菌所具有的降解木质素能力源于其所产生的酶系统,碳源和氮源是其降解木质素和产酶的一个极为重要的影响因素。通过室内小麦秸秆固态发酵试验,研究了不同的碳、氮源对两株侧耳属真菌Tf1（P.pulmonarius）和JG1（P.cornucopiae）产酶活力、木质素降解和粗蛋白含量的影响。结果表明,Lip和MnP是参与复合木质素降解菌Tf1＋JG1降解小麦秸秆重要的木质素降解酶。以葡萄糖为碳源,酒石酸铵为氮源能显著提高复合木质素降解菌对木质素的降解能力,发酵9 d后小麦秸秆的失重率为14.87%,木质素含量为8.68%,木质素降解率为22.95%;粗蛋白含量为7.28%,比未发酵麦秸提高了36.84%（P〈0.05）;Lip和MnP活力分别为629.11 U.g-1和622.22 U.g-1。