Determination of the distribution and reaction of polysaccharides in wood cell walls by the isotope tracer technique VII: Double radiolabeling of xylan and pectin in magnolia (Magnolia kobus DC) and comparison of their behaviors during kraft pulping by radiotracer technique

myo-Inositol-[2-³H] and d-glucuronic acid-[6-¹⁴C] were administered simultaneously to a growing stem of magnolia (Magnolia kobus DC) to label xylan and pectin, respectively, in the cell wall. Determination of the radioactivity of nitrobenzene oxidation products and sulfuric acid hydrolysates of the newly formed xylem indicated that xylan and pectin were labeled with ³H and ¹⁴C, respectively. The doubly labeled wood tissue was treated to kraft pulping, and the radioactivity of the pulping black liquor and treated wood tissue were determined at various stages of the pulping to compare the dissolving behavior between pectin and xylan during the pulping. The results showed that pectin was not dissolved as easily as xylan and was not redeposited on pulp fiber at the late stage of the pulping.Part of this report was presented at the 40th Lignin Symposium at Tsukuba, October 1995     

Populations of bacteria in poplar stems

Wetwood taken from euramerican hybrid poplars (Populus×euramericana) generally contained large and diverse populations of bacteria. The distribution of bacteria within tissues was discontinuous in both radial and axial directions. Most of the common bacterial strains were capable of altering wood components. The bacteria most consistently associated with wetwood were identified as Enterobacter and Clostridium species. The Enterobacter was hemicllulolytic and one Clostridium strain could degrade pectin in anaerobic conditions. These bacteria may play an important rote in the development of wetwood in poplar.     

不同沉淀方法提取柚皮果胶的研究

柚皮经盐酸溶液提取而得果胶提取液,分别以醇沉法和盐析法从提取液中沉淀果胶.研究并获得了两种沉淀方法的最佳沉淀条件,比较了不同沉淀方法的乙醇消耗量,探索了不同沉淀方法对果胶沉淀得率和品质的影响.结果表明:醇沉法所消耗的乙醇量几乎为盐析法乙醇消耗量的两倍.盐析法能大大降低乙醇使用量,省去稀酸提取液浓缩工序和减少乙醇回收量,节省能耗,降低生产成本,并能保证较高的沉淀得率和果胶品质.     

Occurrence and significance of bacteria in living trees of Populus nigra L.

On the occurrence and significance of bacteria in living trees of Populus nigra L. Eleven strains of bacteria were isolated from sapwood and heartwood of living poplar trees (Populus nigra L.) and identified mostly as Erwinia, Xanthomonas, Agrobacterium and Acinetobacter. Most of them were able to attack milled wood and the wood components pectin, hemicelluloses and holocellulose; α-cellulose and lignin were not consumed. The capillary liquid in the xylem of poplar served as a nutrient for the isolated bacteria. The significance of these bacteria for wetwood formation is discussed.     

向日葵盘及其果胶主要组成的研究

研究结果表明，向日葵盘组成复杂，初步测定出１０多种天然化合物，其果胶含量以海绵状肉质部位最高，锯齿形苞片部位最低。用气相色谱法分别测定了向日葵盘及其果胶中各种糖基的相对含量，发现它们都含有木糖、阿拉伯糖、甘露糖、半乳糖和葡萄糖等，向日葵盘中葡萄糖含量最高果胶中含半乳糖最多。向日葵盘用水预洗得到的水溶性果胶，其酯化度大于５０％，属于高酯果胶，其表观分子量为１７３４００，向日葵盘经一分别用稀无机酸及多     

野果果胶提取及发展前景研究进展

本文综述了国内外提取果胶的方法和存在的问题以及果胶在食品和医药领域中的应用及发展前景。     

冰糖脐橙皮中果胶提取方法研究

实验分别采用混合盐析和乙醇沉淀的方法对从冰糖脐橙皮中提取果胶的条件进行研究与探讨,通过实验分别得出最佳提取条件,并比较2种工艺方法的优缺点。     

Boron influences pollen germination and pollen tube growth in Picea meyeri

To study the role of boron in pollen germination and pollen tube growth of Picea meyeri Rehd. et Wils., pollen grains were cultured in standard medium or boron-deficient medium. Effects of boron on the localization of pectins and callose in the walls of pollen tubes were observed by laser scanning confocal microscopy after staining with aniline blue or immunolabeling with antibodies JIM5 and JIM7. Changes in the structures of pectins and phenolics were investigated by fourier transform infrared (FTIR) microspectroscopy. Pollen germination in boron-deficient medium ranged from 18 to 24%, whereas pollen germination in standard medium reached 61%. Callose accumulated in the tip-regions of pollen tubes cultured in boron-deficient medium, but not in standard medium. Immunolabeling with antibody JIM5 revealed that acidic pectin preferentially accumulated in the tip regions of pollen tubes cultured in boron-deficient medium, whereas acidic pectin was weakly distributed along the entire lengths of pollen tubes cultured in standard medium. Esterified pectin, detected by immunolabeling with antibody JIM7, showed a similar distribution pattern in pollen tubes in both the boron-deficient and standard treatments. The FTIR spectra indicated slight increases in contents of phenolics and carboxylic acids and a substantial decrease in the content of saturated esters in boron-deficient pollen tubes compared with normal pollen tubes. The FTIR spectra confirmed that boron deficiency enhanced acidic pectin accumulation in pollen tubes, which may be associated with the increased content of carboxylic acid. We conclude that boron has a regulatory role in pollen germination and pollen tube growth.     

Capability of the European and North American race of Gremmeniella abietina to hydrolyse polygalacturonic acid in vitro

Polygalacturonase was found to be one of the first enzymes secreted by a pathogen during infection. The polygalacturonic-acid hydrolysing activity was compared between the North American and the European race of Gremmeniella abietina in vitro. Isolates were grown in pure pectin media from which the enzyme activity was analysed. Altogether, 29 isolates were tested in five experiments (experimental runs in a growing chamber). The data were analysed using variance-component models that included fixed-race effects and random-experiment, isolate, flask and measurement effects. The European race secreted more polygalacturonic-acid hydrolysing enzyme than the North American race and the mycelial dry weight produced was smaller for the European race. The differences between races were of the same order of magnitude as the variation between isolates within races; variance components relating to experimental errors were quite large. No correlation was found between the activity and mycelial dry-matter production within the races. Logarithmic transformation removed the apparent racial differences in the variability of the activity and mycelial dry weight. Results from the additionally tested A- and B-type of Finnish isolates indicated differences in dry-matter production.     

香蕉假茎纤维成分的分析

以香牙蕉（Musa cavendisihii,Me）的假茎纤维为原料,对它的水分、灰分、水溶物、脂肪和蜡质、果胶、木质素、半纤维素、含胶率和纤维素成分进行了分析。结果表明：纤维素是构成香蕉假茎纤维的主要成分,占总量的55．591％;胶质总含量41．948％,其中脂蜡质含量1．438,果胶含量6．975％,木质素含量8．742％,半纤维素含量17．378％。与其它植物纤维相比,虽然香蕉假茎纤维含纤维素量中等,含木质素较高,但仍然有开发价值。     

Identification of European Armillaria species by analysis of isozyme profiles

Studies were carried out to test the possibility of identifying European Armillaria species by using isozyme patterns. Twenty-two different enzymes were used to analyse the haploid and diploid mycelium extract of Armillaria borealis, Armillaria cepistipes, Armillaria gallica, Armillaria mellea, Armillaria ostoyae and Armillaria tahescens. Tests for fumarase (E.C. 4.2.1.1.), aconitase (E.C. 4.2.1.3.), leucine-amino peptidase (E.C. 3.4.11.1.), isocitrate dehydrogenase (E.C. 1.1.1.42.), shikimic dehydrogenase (E.C. 1.1.1.25), glucose-6-P-dehydrogenase (E.C. 1.1.1.49.), malic enzyme (E.C. 1.1.1.40.), 6-P-gluconic dehydrogenase (E.C. 1.1.4.4.), pectin esterase (E.C. 3.1.1.11.), and pectic lyase (E.C. 4.2.99.3.) did not reveal enzyme activity. Isozyme profiles of acid phosphatase (E.C. 3.1.3.2.), phospho-gluco-isomerase (E.C. 5.3.1.9.), peroxidase (E.C. 1.11.1.7.), polyphenoloxidase (E.C. 1.14.18.), malic dehydrogenase (E.C. 1.1.1.37.), glutamic dehydrogenase (E.C. 1.4.1.3.) and superoxide dismutase (E.C. 1.15.1.1.) were ineffective for species identification. In contrast, esterase (E.C. 3.1.1.1.), glutamic-oxalacetic transaminase (2.6.1.1.), phospho-gluco-mutase (E.C. 2.7.5.1.), alcohol dehydrogenase (E.C. 1.1.1.1.), and polygalacturonase (E.C. 3.2.1.15.) isoenzyme patterns showed enough polymorphism to allow the identification of the different Armillaria species. However, it is necessary to compare several enzyme profiles for a conclusive identification. Intraspecific crosses of A tabescens were confirmed by the presence of a heteromeric isozyme pattern of alcohol dehydrogenase and phospho-gluco-mutase.     

毛竹伐桩快速腐烂技术试验研究

竹伐桩在自然状态下腐烂速度极度级慢，为加快其腐烂速度，增加土地有利用空间，试用尿素、碳酸氢铵、食盐、草甘磷等肥料或农药，木霉、果胶霉等生物菌类单种或组合施于竹桩内腔。结果表明：这些物质都能有效提高竹桩糜烂速度，但提高速率有差别。使用草甘磷与碳酸氢铵、食盐的混合处理是本试验中农药和化肥组合中的最佳组合，它在处理后2年可达到自然状态的6年，腐烂速度提高了3倍。单用果胶霉、木霉处理腐烂速度也可以提高3倍；毛竹桩先加入碳酸氢铵后覆土，再加入一定量的果胶霉、木霉，其处理后23个月竹桩的腐烂程度相当于自然状态下的6年程度，糜烂速度可提高3倍以上。     

白骨壤果实的营养成分及含量

白骨壤果实作为民间食物原料具有较高的粗淀粉、可溶性总糖、粗纤维含量,而粗蛋白、粗脂肪、果胶含量较低,同时具有一定含量的单宁成分。     

Distribution of methyl-esterified galacturonan in chemical and mechanical pulp fibers

The effects of chemithermomechanical pulping (CTMP), high-temperature (HT)-CTMP pulping, and kraft pulping on the distribution of the pectin polymer, methyl-esterified polygalacturonan have been qualitatively evaluated using immunocytochemistry. Pectin was immunolocalized using an antibody (JIM7) specific for partly methyl-esterified polygalacturonan. A fluorescent antibody was linked to JIM7 and analyzed by epifluorescence microscopy. Pectin was found in both chemithermomechanical pulps in similar uneven patterns: Some fibers showed no labeling, whereas others showed extensive labeling in patches restricted to the fiber surfaces. Pectin labeling of bleached and unbleached kraft pulps did not show any presence of pectin. Labeling was correlated to the presence of compound middle lamella tissue left on the CTMP-treated surfaces. Pectin on pulp-fiber surfaces may affect the interfiber bonds and thereby the pulp properties.     

果胶对山楂加工的影响

果胶是一种天然高分子化合物，广泛存在于各种水果中，具有凝胶、粘韧、增稠乳化等作用。山楂中果胶含量达6．4％，居所有水果之首。丰富的果胶物质决定着山楂特有的加工性能和特有的加工产品，从而使其加工产品丰富多彩。     

Protein phosphatases 1 and 2A and the regulation of calcium uptake and pollen tube development in Picea wilsonii

To investigate the roles of protein phosphatases 1 and 2A in the development of pollen tubes of Picea wilsonii Mast., pollen grains were cultured in standard medium in the presence and absence of the protein phosphatase inhibitors okadaic acid and calyculin A. At nanomolar concentrations, these compounds blocked pollen tube growth, causing abnormal morphologies of the pollen tubes. Studies with Fluo-3 revealed that the inhibitors reduced the pollen-tube tip-to-base cytoplasmic calcium (Ca(2+)) gradient and arrested extracellular Ca(2+) uptake. The transmission electron microscope observations indicated that the fusion of paramural bodies with plasma membranes occurred frequently in the tip and sub-tip regions of control pollen tubes, but fusion rarely occurred in inhibitor-treated pollen tubes. Staining with aniline blue showed that callose accumulated in the tip regions of inhibitor-treated pollen tubes. Immunolabeling of pollen tubes revealed that acidic pectin epitopes recognized by the monoclonal antibody JIM5 were present in the tip region and on the flanks of the sub-tip in normal pollen tubes. In inhibitor-treated pollen tubes, these epitopes existed only in the extreme tip region and at higher concentrations than in control pollen tubes. The esterified pectin recognized by JIM7 was located preferentially at the extreme tip region in normal pollen tubes, but at basal sites in inhibitor-treated tubes. Fourier transform infrared (FTIR) analysis further confirmed the changes in acidic and esterified pectin distributions and their relative contents. These results suggest that protein phosphatase 1 or 2A, or both, are involved in the regulation of Ca(2+) uptake across the plasma membrane, in exocytotic activity and in the biosynthesis of cell wall components, all processes that occur in the tip region of pollen tubes and that control pollen tube development.     

沙棘果胶提取工艺研究

以沙棘果实为原料，利用酒精沉析法系统研究了萃取时间、萃取温度、萃取pH值、果胶酶活性和水质等对果胶产量的影响，探讨了酒精沉析法提取沙棘果实中果胶的工艺条件。为工业化生产提供了理论依据。     

Pit membrane chemistry influences the magnitude of ion-mediated enhancement of xylem hydraulic conductance in four Lauraceae species

The ion-mediated enhancement of xylem hydraulic conductivity in angiosperms is thought to be controlled by the pectin chemistry of intervessel pit membranes. However, there is little or no direct evidence on the ultrastructure and chemical nature of pit membranes in species that show an 'ionic effect'. The potential link between the magnitude of the ionic effect and pectin composition in intervessel pit membranes of four Lauraceae species (Laurus nobilis, Lindera megaphylla, Litsea sericea and Umbellularia californica) that show rather similar vessel and pit dimensions was studied using transmission electron microscopy (TEM). The TEM observations confirmed the presence of a pectic matrix associated with intervessel pit membranes, indicating that the relative abundance of acidic versus methylesterified pectins was closely related to the ionic effect. The two species examined with a high ionic effect ~20%, i.e. Laurus nobilis and Umbellularia californica) showed relatively high levels of acidic pectins, whereas methylesterified pectins were abundant in Lindera megaphylla and Litsea sericea, which showed a low ionic effect (~10%). Variation in the ionic effect is strongly associated with the chemical nature of pit membrane pectins in the species studied. Our findings support the current interpretation of the ionic effect due to dynamic swelling and shrinking behaviour of pit membrane pectins.     

竹笋壳的化学脱胶初探

将人们废弃的竹笋壳进行化学脱胶,去除其中的木质素、果胶、蜡质、灰分等,然后对脱胶后纤维的物理机械性能进行测试,结果显示,脱胶后竹笋壳纤维的长度、细度、强力、初始模量等都类似于苎麻,是一种可用的纺织新纤维。     

Isolation, purification and some structural features of the mucilaginous exudate from Musa paradisiaca

The water-soluble polysaccharides isolated from the vascular gel of Musa paradisiaca, were fractionated via anion exchange chromatography into four fractions. Fractionated polymers contained arabinose, xylose and galacturonic acid as major sugars, together with traces of galactose, rhamnose, mannose and glucose residues. Methylation analysis revealed the presence of a highly branched arabinoxylan with a significant amount of terminal arabinopyranosyl units and an arabinogalactan type I pectin. Periodate oxidation studies supported the results of methylation analysis.