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木质生物资源的水解 总被引：17，自引：3，他引：14
水解是利用木质生物资源以生物转化法制取乙醇的重要步骤,水解技术主要包括稀酸水解、浓酸水解和酶水解。酶水解的特点是具有选择性,降解产物少,葡萄糖得率高,能耗较低,不要求反应器具有高耐腐蚀性,被视为最有潜力降低乙醇生产成本的突破口。目前,利用木质生物资源制取乙醇还没有进入工业化生产。其原因在于成本高于利用淀粉和糖料,原料的预处理成本高、纤维素酶的生产成本高、酶活力低、纤维素的酶水解效率低、酶用量大、对半纤维素的有效利用不够。因此,需要研发有效的预处理工艺,提高纤维素底物的生物酶可及度;筛选高效纤维素酶、优化酶水解工艺,提高纤维素的水解率;利用基因重组的发酵性微生物,把戊糖发酵成乙醇,提高乙醇的产量,降低生产成本。 相似文献
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The alkaline extraction – glucoamylase hydrolysis (AG) method, which extracts sugars and starch by using sodium hydroxide
and hydrolyzes starch by using glucoamylase and α-amylase, was compared with the established ethanol extraction – perchloric acid hydrolysis (EPA) method to analyze the sugar
and starch contents of moso bamboo (Phyllostachys pubescens Mazel). The results suggested that the two methods had comparable abilities to extract free sugars from moso bamboo. However,
the AG method analyzed starch in moso bamboo more accurately than the EPA method under the proper conditions. When we take
into account the better time performance of the AG method versus the EPA method, we can conclude that the AG method is superior
to EPA for analyzing the sugar and starch contents of moso bamboo. 相似文献
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毛竹竹材由于富含淀粉和糖,在适宜的条件下极易受到以此为食的各种霉菌的侵害,给竹材加工业造成重大的损失,因此必须进行竹材的防霉保护。传统的化学药剂浸渍竹材,虽然防霉效果优异,但因其含有对人体有害的化学物质或重金属成分,长期使用会影响人类的身体健康。而利用生物酶进行竹材的防霉处理,不但简便高效,而且绿色无毒。在研究过程中采用7种不同酶量的淀粉酶溶液来处理竹材样品,同时对比了最适加酶量下3种不同处理时间和3种不同处理温度对竹材样品防霉的效果。试验结果表明:随着淀粉酶处理液中酶量的增加,竹材样品的淀粉和还原糖含量下降明显;淀粉酶处理液的处理时间对降低竹材淀粉和还原糖含量起到关键作用,适当延长竹材的酶处理时间有益于降低竹材的淀粉和还原糖含量;适合的淀粉酶处理温度能提高淀粉酶水解效率,降低竹材淀粉和还原糖含量。在竹材的防霉试验中,经淀粉酶溶液处理过的竹材,对3种霉菌(黑曲霉、桔青霉和绿色木霉)均有很好的抗霉效果;随着淀粉酶处理液酶量和处理时间的增加,竹材的防霉性能有了明显的提高。结果表明,最佳淀粉酶处理工艺为:酶量120 U/mL,酶处理时间36 h,酶处理温度95℃。研究结果可为竹材的防霉研究提供参考。 相似文献
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生物质制乙醇是解决当前世界能源短缺的重要途径。当前生物质制乙醇在国内外无法大规模投入生产的主要原因是成本过高。选取优质的生物质材料和高效的预处理方法可以有效解决这一问题。以6个泡桐品种为试验材料,采用稀硫酸、氢氧化钠、微波-氢氧化钠3种方法进行预处理,对泡桐纤维素含量和酶解后还原糖产量进行测定,探讨不同预处理方法对纤维素含量和还原糖产量的影响。结果表明:以微波-氢氧化钠法预处理毛泡桐品种效果良好,处理后纤维素含量达84.82%,较预处理前提升了38.01%;半纤维素和木质素分别降低了21.23%和6.65%;还原糖产量较高,为471.38 mg/g。该研究可为生物质制乙醇高效预处理方法和优质生物质材料的选择提供参考。 相似文献
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Aging of the donor tree decreased adventitious root formation in shoot cuttings of Tectona grandis Linn. f. (teak). Exogenous application of auxins, i.e., α-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) has
a significant positive effect on the percentage of rooting. The maximum percent rooting was obtained with 4,000 ppm IBA as
compared to other treatment. Significant increase in root number was recorded in shoot cuttings treated with 4,000 ppm NAA.
The overall rooting response was better in the treatment with IBA rather than with NAA. Further periodic samples (0, 10, 20,
and 30 days) were taken to assess the total soluble sugar, starch, protein, and peroxidase (PER) activity in the rooting zone
of shoot cuttings of teak during adventitious root formation. Application NAA and IBA to shoot cuttings resulted in an increase
in the level of total soluble sugar, starch, protein, and PER-activity in the rooting zone. The stored carbohydrates were
utilized during adventitious root formation. Hence, total soluble sugar and starch contents of cuttings, irrespective of age
of donor plants, decreased with the passage of time in cuttings planted for rooting. Significant fluctuations were observed
in the protein content of cuttings during the time of root induction. There was an increase in the protein content with the
passage of time from the day of planting up to its 20th day, followed by a sharp decline in the protein content of cuttings
at the 30th day of planting, irrespective of the age of donor plants or the treatment of cuttings with auxins. Irrespective
of donor plant age, PER-activity in the cuttings increased from the day of their planting for rooting up to the 20th day,
and then declined at its 30th day of planting. It was interesting to note that PER-activity remained higher at all stages
in the cuttings of 2-month-old seedlings which rooted profusely as compared to the cuttings of 15- and 30-year-old donor plants
those rooted poorly. This study suggested that the exogenously applied NAA and IBA at different concentration seems to activate
sugar metabolism for release of energy, protein and PER-activity which are necessary for cellular division and differentiation
during adventitious root primordium initiation or development in the rooting zone of shoot cuttings. 相似文献
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为延长蓝莓贮藏时间,以‘灿烂’蓝莓为试材,将果实放入不同的缓释保鲜纸后在PE袋中低温冷藏,对贮藏期间鲜果的质量损失率、硬度、还原糖含量、可滴定酸含量、总酚含量、花色苷含量等理化指标进行测定分析,研究1-MCP和SO_2缓释保鲜纸对蓝莓采后冷藏品质的影响。结果表明:1-MCP缓释保鲜纸可有效减少蓝莓的质量损失,维持蓝莓硬度,减少坏果率,提高和保持还原糖和花色苷含量,降低可滴定酸和总酚含量,延缓可溶性固形物含量高峰的出现,使蓝莓保持良好的风味和耐贮藏性。SO_2缓释保鲜纸及1-MCP缓释保鲜纸和SO_2缓释保鲜纸一起使用,虽能够减少蓝莓质量损失,增加硬度,但对还原糖、花色苷、可滴定酸、总酚含量等指标无积极作用,且SO_2药害的存在,使得蓝莓外观受到严重影响,风味大幅下降,因此不适合用于蓝莓保鲜。 相似文献
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为了全面掌握胡颓子属植物果实的营养状况,从而为其优良种质资源的筛选与综合开发及利用提供参考依据,利用色谱分离、凯氏定氮及原子吸收光谱等检测技术,对南方地区不同产地的胡颓子属植物40份果实样品的可食率、可溶性固形物、总酸、总糖、VC、VB1、蛋白质、全磷、钙元素等营养成分进行了测定与分析。测定结果表明:40份果实样品的可食率为60.1%～73.1%,总酸为0.51%～0.69%,总糖为3.22%～4.82%,糖酸比为6.1～7.1,蛋白质为1.75%～2.28%,每100 g样品中含有的可溶性固形物、VC、VB1、全磷、钙分别为5.60～16.85 g、4.20～5.79 mg、2.79～4.26 mg、12.7～29.30 mg、19.3～61.6 mg。分析结果表明:胡颓子属植物果实具有很高的营养价值和较好的开发利用前景。 相似文献
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澄江引进的4种兔眼蓝莓品种果实的外观性状及物质含量分析 总被引：1，自引：0，他引：1
对云南省澄江县引种的杰兔、粉蓝、园蓝、灿烂4个兔眼蓝莓品种果实的外观性状及物质含量进行了测定,进而对其果实的综合营养品质进行了评价。结果表明:4个兔眼蓝莓品种扁球形为小果型,单果重小于1 g。果实中蛋白质、总糖、总酸、Vc、可溶性固形物、水分、纤维素的含量变幅依次为251.89~531.18 mg/100g、5.76~8.03 g/100g、0.08%~0.13%、3.75~5.40 mg/100g、14.8%~16.6%、81.38%~82.75%、7.91%~15.30%,矿质元素P、K、Ca、Mg、S、Fe、Zn、Cu、Mn含量较丰富。不同品种间,果实中营养成分含量差异明显。果实综合营养品质最好的品种是杰兔,最差的是园蓝。 相似文献
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以东北地区常见野生芹菜为研究对象,对其水分、灰分、粗纤维、粗蛋白、粗脂肪、糖(总糖、还原糖)、维生素(C、胡萝卜素)、氨基酸种类及含量(总氨基酸含量、8种必需氨基酸含量)、总黄酮含量(提取时间、乙醇浓度对其影响)、硝酸盐含量等营养成分进行分析的结果表明:①四种野生芹菜与家芹相比而言,灰分、粗纤维、粗蛋白、维生素C等含量均明显高于家芹;②四种野生芹菜矿质元素含量明显高于家芹中矿质元素含量;③拐芹、大叶芹、棱子芹中氨基酸含量和家芹中氨基酸含量无明显差异,碎叶山芹中各种氨基酸含量明显高于其他几种芹菜。 相似文献
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Stage-specific analyses of starch and 18 sugars, including pentoses, hexoses, disaccharides, trisaccharides, oligosaccharides and sugar alcohols, were made throughout seed development for zygotic embryo and female gametophyte (FG) tissues of loblolly pine (Pinus taeda L.). Tissue was most often analyzed in triplicate from two open-pollinated families grown in different locations and sampled in different years. Carbohydrates were analyzed by enzymatic assay, high performance liquid chromatography or gas chromatography/mass spectrometry. For all carbohydrates quantified, peak concentrations were higher in embryo tissue than in FG tissue. Significant changes in starch and sugar concentrations occurred over time, with both seed collections showing similar trends in temporal changes. Although concentrations were not always similar, embryo and FG tissues generally showed similar patterns of change in starch and sugar concentrations over time. Total starch concentration was highest during early seed development and decreased as development progressed. The major sugars contributing to osmotic potential during early seed development were D-pinitol, sucrose, fructose and glucose. During mid-seed development, D-pinitol, sucrose, fructose, glucose, melibiose and raffinose provided major contributions to the osmotic environment. During late seed development, sucrose, raffinose, melibiose, stachyose and fructose were the major contributors to osmotic potential. These data suggest stage-specific media composition for each step in the somatic embryogenesis protocol. 相似文献
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以北美香柏嫩枝插穗为材料,用ABT2和GGR6处理插穗,以清水处理为对照,研究扦插生根过程中营养物质的变化。结果表明:各处理的插穗,在其生根过程中可溶性总糖含量变化趋势较为相似,在根诱导期和伸长期出现峰值。ABT2处理的插穗可溶性总糖含量较高,对照的含量相对较低,推测可溶性总糖对生根起促进作用。插穗氮含量在生根过程中整体呈下降趋势,对照的氮含量高于其他处理,可能是低氮的条件更有利于生根。C/N值的变化趋势与可溶性总糖一致。可溶性总糖、C/N值与生根率的灰色关联度分析表明,可溶性总糖和C/N值可能是调控插穗生根的主要因子,且在根诱导期和伸长期作用明显。 相似文献
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Yasuyuki Matsushita Hitomi Sano Masanori Imai Takanori Imai Kazuhiko Fukushima 《Journal of Wood Science》2007,53(1):67-70
To study the behavior of hardwood sulfuric acid lignin (SAL) during phenolization, we compared the product yield, average
molecular weight, methoxy content, and reactions of simple model compounds with those of softwood SAL, focusing on the difference
between syringyl and guaiacyl units. The beech SAL reacted with phenol more readily than red pine SAL and yielded a larger
soluble fraction of phenolized SAL. To investigate the difference in the phenolization activity of the syringyl and guaiacyl
units in beech lignin, we prepared syringyl-nucleus-rich sulfuric acid lignin (S-rich-SAL) and guaiacyl-nucleus-rich sulfuric
acid lignin (G-rich-SAL) from beech, which were subjected to phenolization. The results suggest that the syringyl unit in
SAL had greater phenolization activity and its phenolized products were more soluble in acidic aqueous medium and introduced
less phenol than the guaiacyl unit. Using model compounds, the study also showed that the syringyl unit had higher phenolization
reactivity than the guaiacyl unit. 相似文献
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In order to obtain the effects of acid catalysts on wood liquefaction in phenol, we investigated the liquefaction of wood
powder from Chinese fir (Cunninghamia lanceolata) and poplar (Triploid Populus tomentosa Carr) in the presence of phenol with the following weak inorganic acids as catalysts: phosphoric acid (85%), sulfuric acid
(36%), hydrochloric acid (37%) and oxalic acid (99.5%). Results show that phosphoric acid (85%) and sulfuric acid (36%) are
better than the other catalysts. It was found that lower residue ratios can be obtained under defined reaction conditions:
phenol/wood ratio is 4, a 10% catalyst based on the weight of phenol, a temperature of 150°C for 2 h and phosphoric or sulfuric
acid. The residue ratios are 3.2% and 4.0%, respectively.
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Translated from Journal of Beijing Forestry University, 2004, 26(5) [译自: 北京林业大学学报, 2004, 26(5)] 相似文献
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11 种城市木本植物叶片生理物质对遮荫的响应 总被引：2，自引：0，他引：2
通过遮光率45%、75%和全光照3种光生境的植物栽培试验,测定了11种城市木本植物叶片叶绿素、花青素、可溶性糖、淀粉和蛋白质的变化,分析了遮荫对不同木本植物生理物质变化的影响,结果表明,遮荫能增加多数植物的叶绿素含量,明显降低花青素含量,特别是色叶植物,从而影响色叶植物的叶色效果,遮荫可减少色叶植物可溶性糖的含量,而增加非色叶植物可溶性糖含量,但对不同类型植物可溶性糖含量的影响幅度不一;遮荫能减少大多数植物的淀粉含量,但使部分色叶植物的淀粉含量增加,而不同遮荫程度对植物叶片淀粉含量的影响没有明显的规律性;光生境变化对植物叶片蛋白质影响缺乏明显的规律性,影响幅度也不一。 相似文献
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研究了硫酸催化条件下,将恩茅松在苯酚中液化用于制备酚醛树脂的技术工艺,分析了各工艺参数对思茅松液化效率的影响,测定了由液化产物制备的液化木基酚醛树脂的物理化学性质和胶合强度。结论如下：1）．液比、反应温度、时间和木粉目数是影响液化反应效率的重要因素,液化产物的残渣率均随上述工艺参数值的升高而降低。2）．残渣含量对树脂物化性质和胶合强度均有影响,残渣含量降低,树脂粘度减小,聚合时间缩短,游离酚含量降低,胶合强度升高。3）．甲醛／苯酚摩尔比对树脂的物化性质和胶合强度也有影响,甲醛／苯酚摩尔比增加,树脂粘度增加,聚合时间减少,游离酚含量减低,胶合强度升高。 相似文献