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1.
N~+注入诱变黑曲霉选育单宁酶生产菌株 总被引:1,自引:0,他引:1
以黑曲霉为出发菌株,经多次N+注入诱变,得到突变高产单宁酶菌株黑曲霉ANO2。该突变菌株其产单宁酶酶活为670.2 U/mL,较出发菌株的单宁酶酶活442.3 U/mL提高51.4%以上,突变菌株经传10代培养,产酶特性稳定,是一株比较理想的单宁酶生产菌株。 相似文献
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通过平板涂布、划线分离、菌落观察等方法,从土耳其倍子提取液自然生长的菌落中分离纯化出11株菌,从中初筛出1#、2#、4#这3株降解没食子单宁的菌株,复筛出1株没食子单宁优良降解菌株1#菌,其没食子单宁降解率达65%以上,发酵液中没食子酸质量浓度为0.052 3 g/L,单宁酶活为0.920 U/mL;对1#菌株的发酵条件进行了响应面法优化,结果表明:1#菌最佳产酶条件为培养温度31℃,初始培养基pH值5.0,最适培养时间50 h,在该条件下1#菌单宁酶酶活可达1.170 U/mL,与优化前的最大酶活0.920 U/mL相比,提高了27.2%。 相似文献
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单宁胶刨花板制造工艺 总被引:2,自引:0,他引:2
从制造人造板的单宁胶基本结构与基本性质入手,分析单宁胶刨花板制造工艺特点与工艺参数。介绍了4种刨花板用单宁胶配方与其条件下的刨花板性能。喷胶与直接拌胶方式的比较,热压工艺条件等的变化均建立在单宁胶的基本性质上。 相似文献
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为了解植物中绿原酸合成代谢途径关键酶的理化性质和进化关系,收集了NCBI数据库中绿原酸代谢途径3个关键酶(Hqt、Hct、C3h)的序列信息,利用在线软件ExPASy-ProtParam分析了它们的理化性质,利用MEGA-7软件比较了它们的序列相似性并建立进化树。理化性质分析结果表明:合成绿原酸的3种关键酶多为亲水性蛋白质,各类基础性质相近,但金银花C3h分子的等电点与其他植物不同。序列相似性分析结果表明:金银花绿原酸代谢途径中的Hqt与桔梗Hqt相似度较高,金银花Hct与烟草Hct的相似度较高。通过研究进一步了解了绿原酸合成代谢途径关键酶的情况。 相似文献
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植物纤维原料酶法水解的研究 总被引:7,自引:1,他引:6
研究了底物性质、底物浓度、纤维素酶的用量及酶系组成等因子对植物纤维原料酶解效率的影响作用,从而为进一步优化可再生纤维素资源的酶法糖化工艺提供了理论和实验依据。 相似文献
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从连作中土壤微生物、土壤营养状况、土壤理化性质及土壤酚酸类物质与土壤酶的关系这四个方面分别进行了综述,旨在为改善连作中土壤理化性质,提高土壤营养水平,减轻连作障碍提供一定的理论依据。 相似文献
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微乳凝胶固定化单宁酶催化没食子酸酯的合成 总被引:1,自引:0,他引:1
没食子酸酯是一类优良的抗氧化剂,为了避免化学合成方法带来的弊端,建立了微乳凝胶(MBGs)固定化单宁酶催化系统,催化没食子酸(GA)与不同的脂肪醇进行酯化.Na2SO4-Na2SO4·10H2O盐水合对可有效调控有机相固定化酶催化系统中水的活度,其调控能力与盐水合对的总量有关.在反应系统中加入盐-盐水舍对(Na2SO4-Na2S04·10H2O)可以明显提高GA的转化率.当pH值6、温度28℃、振摇速度150 r/min时,在生产没食子酸丙酯(PG)、没食子酸丁酯(BG)的MBGs反应系统中,加入总量1.8 g,比例为1:1的Na2SO4-Na2SO4·10H2O,GA的转化率可分别达到78.2%和85%,比对照样分别提高93.0%、129.7%;在生产没食子酸戊酯(AG)的MBGs反应系统中,加入总量2.4 g,比例为1:1的Na2SO4-Na2SO4·10H2O,GA的转化率为72.4%.比对照样提高103.7%. 相似文献
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Kayoko Imai Tohru Mitsunaga Hiroyuki Takemoto Toshihiro Yamada Shin-ichiro Ito Hideo Ohashi 《Journal of Wood Science》2009,55(2):126-132
The extracts of Quercus crispula infected by the ambrosia fungus, Raffaelea quercivora, were investigated. Phenol and tannin analyses indicated that normal sapwood (NS) contained a considerable amount of hydrolysable
tannins, while infected colored sapwood (IS) contained less hydrolysable tannins and more phenols than NS. In treating pentagalloyl
glucose (PGG), which is a model compound of hydrolysable tannins, with a culture medium of R. quercivora, PGG was rapidly hydrolyzed to produce gallic acid. The resulting gallic acid decreased in concentration over the subsequent
cultivation period eventually disappeared. Measuring tannase and laccase activities of the culture medium of R. quercivora, tannase activity increased gradually from the beginning, while laccase activity increased rapidly at 5 days of incubation
and disappeared at 8 days. An oxidative product from gallic acid treated with laccase was isolated by preparative high performance
liquid chromatography, and was identified as purprogallincarboxylic acid (PGCA) by nuclear magnetic resonance spectroscopy
and electron-impact mass spectrometry. PGCA was present in a 70% aqueous acetone extract of IS, and showed slight growth inhibition
against R. quercivora.
Part of this study was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, Japan, 2007 相似文献
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以不同前角刨刀切制两种杨木和柞木刨片,根据参数分离法,对其流变性能进行了测定和研究。结果表明:刀具前角不同可导致刨片的流变性能变化;刀具前角增大,刨片流变性能的变化对提高刨花板的性能有利;刀具前角对刨片流变性能的影响在不同树种中基本趋势一致,但对刨花板性能的影响可能因树种而有所不同。 相似文献
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T. Ona T. Sonoda K. Ito M. Shibata Y. Tamai Y. Kojima J. Ohshima S. Yokota N. Yoshizawa 《Wood Science and Technology》2001,35(3):229-243
Relationships between cell and pulp properties were investigated by examining the within-tree property variations in Eucalyptus camaldulensis and Eucalyptus globulus. Properties investigated included proportions of ray and axial parenchyma, thickness of cell walls and cell wall percentages.
The characteristics of the ray and axial parenchyma (their proportions and wall thickness) were found to have a significant
influence on all measured pulp properties, including paper strength properties. Multiple regression of pulp properties in
relation to cell properties revealed that nearly all measured pulp properties were explained by cell properties at the 1%
significance level. It was concluded, therefore, that all cell types are important for predicting pulp properties, and it
is strongly recommended that tree breeding programs for Eucalyptus include the measurement of all cell types.
Received 6 July 1999 相似文献
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为了进一步优化木材资源,需要对木材的性质进行检测。本文阐述传统木材的解剖性质、物理及化学性质的检测方法,在物理性质树干气密度的测试中,例举了近红外光谱检测方法,以期为其他木材性质检测做参考。 相似文献
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通过对27个3年生不同桉树无性系的几个主要性状进行调查,运用比较、方差分析、相关分析等方法,分析不同无性系主要性状的种间差异以及各性状间的相互关系。结果表明:不同地点立地条件、不同桉树无性系的年均蓄积量差异极显著,两者之间存在极显著的交互作用。干形指标与其产量存在极显著的负相关;树高、胸径之间存在显著的表型和遗传相关;通过干形指标和无约束指数选择法,综合评定了各无性系的生长表现,选出ECl、CH3、CH1等18个表现优良的无性系。 相似文献
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Erik Larn y Sebastian Dantz Morten Eikenes Holger Militz 《Wood material science & engineering》2006,1(2):59-68
Chitosan is a biopolymer derived from chitin in crustacean shells. Over the past decade it has been studied as an environmentally benign wood-protecting agent. It is assumed to act as a fungi-stat against a wide range of fungi and even as a fungicide at higher concentrations. This study investigated the properties of wood treated with modified chitosan of different molecular weights. Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) samples were impregnated with two chitosan solutions differing in their average molecular weights. The chitosan solutions were depolymerized by nitrous acid to one solution of high molecular weight and one solution of low molecular weight with a concentration of 5% (w/v). The results show changes in sorption properties, antifungal properties, fire-retardant properties and mechanical properties of modified chitosan-treated wood. Heat-modified, chitosan-treated wood showed similar properties to chitosan-treated wood, except for brownish coloration, enhanced hydrophobation, and slightly reduced antifungal and fire-retardant properties. The modulus of rupture and hardness showed little or no change. The modulus of elasticity of the heat-modified, chitosan-treated wood increased by 27% compared with untreated wood. 相似文献