基于生物质精炼的杜仲全组分结构解析及其解离机制研究

发布时间：2018-01-13 03:10

  本文关键词：基于生物质精炼的杜仲全组分结构解析及其解离机制研究　出处：《西北农林科技大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 生物质精炼 杜仲 结构解析 解离机制

【摘要】：杜仲(Eucommia ulmoides Oliver,EU)单科单属单种,为中国特有的经济树种,在中国的种植面积占世界资源总量的95%以上。杜仲从杆、叶、皮到果实,浑身都是宝,尤其是可以提取作为国家战略资源的杜仲橡胶,其研究和生产实际意义重大。由于杜仲产业的特殊性,目前依然有一些难题亟需攻克,首先是如何低成本的获取杜仲资源作为产业化发展的基础;再者是如何基于生物质精炼的杜仲全组分高效提取分离和产品开发;最后是如何阐明杜仲全组分在高值化提取分离过程中的解离机制成为杜仲产业化方面的难题之一。上述问题的解决不仅对于杜仲资源配置方面的研究具有重要的推动作用,而且涉及到健康食品、保健品以及其他相关产品的大规模开发和利用提供重要的理论基础。本文从杜仲资源培育模式的生理特征和次级代谢产物积累规律的关系出发,分析了杜仲叶林栽培模式和乔林栽培模式初级代谢和次级代谢之间规律,阐明的两种栽培模式的物质积累差异性原因。此外,针对杜仲资源方面的不同器官,提出了几种基于生物精炼的杜仲资源高效清洁提取分离及利用的方法,并对这些处理过程中解离机制进行了深入的探讨。系统的研究杜仲叶林栽培模式和传统乔林栽培模式下形态特征与生理生态特性的差异,对促进我国杜仲高效栽培模式与技术创新及可持续利用具有重要意义。以叶林栽培模式和乔林栽培模式的杜仲树为材料,检测了杜仲树生长期内形态特征、光合生理、化学成分和生物量动态变化规律,系统探讨了栽培模式对其生长与生理特征的影响。结果表明:不同测定时期,乔林栽培模式下杜仲叶片的最大净光合速率(Pnmax)和水分利用效率(WUE)显著低于叶林栽培模式;除10月中旬外,杜仲乔林栽培模式的叶片光响应曲线的表观量子效率(AQE)均显著低于叶林栽培模式;两种栽培模式的杜仲叶片暗呼吸速率(Rd)和光补偿点(LCP)均随生育期的延续呈降低的变化趋势;杜仲乔林栽培模式的株高、地径和胸径均显著高于叶林模式,但其叶片面积呈相反趋势;10月中旬时,乔林栽培模式的茎、皮和叶生物量干重均显著低于叶林栽培模式。综合所述,在杜仲叶林栽培模式下除株高、地径和胸径等形态特征外,叶面积、光合能力、生物量累积等生理生态特性方面较传统乔林栽培模式均具有明显的优势。利用杜仲树皮(乔林和叶林)以及杜仲树叶为原料,将杜仲叶和树皮先后用热水提取、碱处理、酶水解的多步集成处理,获得杜仲浸膏、杜仲水溶性多糖、碱提多糖和杜仲胶。研究结果表明,杜仲叶中提取出浸膏的生物活性成分主要由绿原酸、槲皮素、京尼平甙、桃叶珊瑚甙组成,而杜仲树皮中提取出浸膏的生物活性成分主要由京尼平苷酸、京尼平苷、桃叶珊瑚苷组成。此外,从树皮和树叶提取出的水溶性多糖主要由葡萄糖组成,而碱提多糖主要由阿拉伯糖组成。另外,从树皮中分离得到的杜仲胶比树叶中的杜仲胶具有较高的分子量和较窄的分子量分布。通过分析可知集成的多步处理是一种环境友好型的方法,有利于杜仲资源在产业化过程中产品的升级和产值的增大,有效的降低了成本,提高了杜仲产品的市场竞争力。杜仲木材生物量比树皮和树叶高,对于杜仲木材的基础研究意义重大。本研究利用杜仲木材为原料,主要探索了杜仲木材经过自水解和有机溶剂脱木素协同处理的过程中木质素的结构变化对于木材酶水解效率的影响。通过自水解预处理可以降解半纤维素,从而分离出低聚木糖,随后的有机溶剂脱木素过程,可以获得高纯度的木质素和富含纤维素的基质。研究结果表明,与磨木素相比,经过协同预处理后的木质素具有较低的分子量、窄的分散度、较高的酚羟基含量和高的S/G值。利用核磁共振对于所得的木质素的结构进行了表征发现,经过协同预处理后,所得的木质素的β-O-4键断裂的比较严重,形成了对苯基乙烯的结果单元,同时也发现在有机溶剂脱木素过程中,木质素的β-β结构单元降解不是非常严重。此外,对于富含纤维素的基质经过酶水解处理。结果发现,经过协同预处理的基质经过酶水解其葡萄糖得率达到了89.3%,该结果分别是有机溶剂预处理基质的1.0倍,自水解基质的1.3倍,杜仲木材的3.8倍。该协同过程,不但获得了高纯度的木质素,同时也为杜仲木材生物乙醇的高值化利用提供了新的途径。利用杜仲叶林枝木为原料,探索蒸汽爆破和碱性过氧化氢预协同处理的过程中,木质素结构的变化对于木材酶水解效率的影响。蒸汽爆破预处理破坏了木质纤维素的结构,随后的碱性过氧化氢预处理过程分离得到了高纯度的木质素和富含纤维素的基质。研究结果表明,与蒸汽爆破磨木素相比,经过协同预处理后的木质素具有低的分子量、窄的分散度、低含量的酚羟基值和低的S/G值。利用核磁共振对于所得的木质素的结构进行了表征发现,与蒸汽爆破磨木素相比,碱性过氧化氢处理过程中轻微的对于木质素的成分和结构单元有所影响,表现在经过碱性过氧化氢处理后,所得的木质素结构单元中β-O-4、β-β和β-5含量较高。此外,经过协同预处理的残渣其葡萄糖得率提高到91.69%,这是因为协同预处理过程中可以分离大量的木质素和半纤维素,促使获得了高结晶度和比表面积的富含纤维素的基质。协同预处理的过程是一个环境友好型的预处理过程,获得了高纯度的木质素和富含纤维素基质的同时,为杜仲木材转化为生物材料和生物乙醇提供了有效的途径。基于生物精炼的杜仲木材自水解预处理和炭活化后处理的协同处理过程,经过不同条件的自水解预处理可以获得低聚木糖(XOS,1.5-34.4%)和半纤维素的降解产物,后续炭活化过程生产的高性能活性炭和少量的不可冷凝气体。结果表明,在基于100 kg杜仲木材的基础上,自水解预处理的最佳条件(170℃,1h),随后炭活化(50%H3PO4,550℃,120 min)自水解基质的协同处理过程,可以得到10.37 kg低聚木糖,1.39 kg半纤维素的降解产物,17.29 kg来自半纤维素的其他产品和40.72 kg活性炭(SBET 1534.06 m2/g)。其中,在所有活性炭样品中AC170-1.0的比表面积为最高。同时,从最佳综合过程中产生的不可冷凝气体(29.14 kg)比从直接炭活化处理(68.84 kg)产量显著降低。此外,通过催化甲烷分解制氢实验表明最佳活性炭样品(AC170-1.0)具有较好的催化活性和较高稳定性。总体而言,基于生物精炼的综合过程同时获得品质较优的低聚木糖和高性能活性炭,这有效的提高了杜仲木材的热解产业的附加值和工业应用前景。
[Abstract]:(Eucommia ulmoides Oliver, Eucommia EU) a single species, for China unique economic species in Chinese planting area accounted for more than 95% of the total world resources. From eucommia leaf, fruit bar, skin, whole body is a treasure, especially can be extracted as Eucommia rubber and the national strategic resources, and its research the actual production of great significance. Because of the particularity of Eucommia industry, at present there are still some problems need to be overcome, the first is based on how low cost acquisition of Eucommia resources as the industrial development; and how biomass refining Du Zhongquan components and product development based on efficient extraction and separation; and finally how to clarify Du Zhongquan components in high value the extraction and dissociation mechanism of the separation process has become one of the difficult problems of the industrialization. To solve these problems not only for the study of Eucommia resources allocation role is important, but Related to health food, provide an important theoretical basis for large-scale development and utilization of health care products and other related products. From the perspective of relationship resource cultivation mode of Eucommia ulmoides physiological characteristics and secondary metabolite accumulation, analyzes the regularity between forest cultivation mode and cultivation of Eucommia ulmoides Colin model of primary metabolism and secondary metabolism, the reasons for difference in two the cultivation mode of material accumulation. In addition to clarify, in view of the different organs of Eucommia ulmoides resources, put forward several methods of separation and utilization of bio extraction refined Eucommia resources and efficient cleaning based on the dissociation mechanism of these processes is discussed. The difference of forest cultivation pattern system of Eucommia ulmoides and traditional cultivation pattern of Colin the morphological characteristics and physiological and ecological characteristics, to promote China's efficient cultivation mode and technology innovation and sustainable utilization of Eucommia ulmoides out Is of great significance. In forest cultivation mode and forest cultivation mode of Eucommia ulmoides were examined the morphological characteristics of Eucommia ulmoides growth period, photosynthetic physiology, variation of composition and dynamics of biomass chemistry, discusses cultivation pattern on growth and physiological characteristics of it. The result showed that different testing period. Joe forest cultivation mode of Eucommia leaf maximum net photosynthetic rate (Pnmax) and water use efficiency (WUE) was significantly lower than that of forest cultivation mode; in mid October, Joe forest cultivation mode of Eucommia ulmoides Ye Pianguang response curve of the apparent quantum efficiency (AQE) were significantly lower than that of forest cultivation mode; Eucommia ulmoides leaves of two kinds of cultivation patterns the dark respiration rate (Rd) and light compensation point (LCP) with the continuation of growth stages had a decreasing tendency; Joe forest cultivation mode of Eucommia plant height, ground diameter and DBH were significantly higher than those in model, but the leaf area was in the opposite Trend; in mid October, Joe forest cultivation pattern of stem, bark and leaf dry weight were significantly lower than those of Ye Lin. The comprehensive cultivation mode, cultivation mode of Eucommia ulmoides in Ye Lin except plant height, ground diameter and DBH morphological characteristics, leaf area, photosynthetic capacity, biomass accumulation, physiological and ecological characteristics compared with the traditional Qiao Lin cultivation mode has remarkable advantages. The use of Eucommia ulmoides Oliv (Qiao Lin and Ye Lin) and Eucommia ulmoides leaves as raw material, the leaves and bark of Eucommia successively with hot water extraction, alkali treatment, multi step integrated processing of enzymatic hydrolysis, obtain Eucommia extract, Eucommia polysaccharide, alkaliextracted and eucommia glue. The results show that the leaves of Eucommia ulmoides extract bioactive constituents of extract mainly composed of chlorogenic acid, quercetin, geniposide, aucubin, and Eucommia ulmoides Oliv extract bioactive constituents of extract is mainly composed of geniposidic acid, geniposide, peach Ye Shanhu was formed. In addition, from the bark and leaves of extracting water soluble polysaccharide was composed of glucose, and alkaline polysaccharides mainly composed of Arabia sugar. In addition, the molecular weight of the separation of Eucommia ulmoides gum obtained from the bark is higher than that in the leaves of Du Zhongjiao and a narrow molecular weight distribution through the analysis. Integrated multi step processing method is a kind of environment friendly, is conducive to the increase of Eucommia resources in the industry in the process of the upgrading of products and output, effectively reduce the cost, improve the market competitiveness of the products. The wood of Eucommia eucommia bark and leaf biomass ratio for wood based high, Eucommia research is of great significance. This study uses Eucommia wood as raw material, mainly to explore the Eucommia wood after the structural changes of lignin during self hydrolysis and organic solvent delignification treatment for wood synergistic enzymatic hydrolysis efficiency influence. By self hydrolysis pretreatment can degrade hemicellulose, thereby separating the xylooligosaccharides, lignin removal process of organic solvent followed, can obtain high purity of lignin and cellulose rich matrix. The results show that, compared with the MWL, through the wood quality collaborative after pretreatment with a low molecular weight and narrow dispersion the high content of phenolic hydroxyl group and high S/G value. The use of nuclear magnetic resonance for the wood element structure is characterized by that synergistic pretreatment, beta -O-4 bond breaking the lignin is serious, the formation of the phenyl ethylene unit, also found in organic solvent delignification in the process of beta beta degradation of lignin structural unit is not very serious. In addition, the matrix is rich in cellulose by enzyme hydrolysis treatment. The results showed that after CO matrix pretreatment after enzymatic hydrolysis of the grape Sugar yield reached 89.3%, the results were 1 times of organic solvent pretreatment matrix, since 1.3 times the hydrolysis of substrate, 3.8 times. The collaborative process of Eucommia wood, not only to obtain high purity of lignin, but also for Eucommia wood bio ethanol is a new way to provide high utilization value. The use of Eucommia forest branch wood as raw materials, to explore the steam explosion and alkaline hydrogen peroxide pre co processing process, influence the change of lignin structure for wood hydrolysis efficiency. Steam explosion pretreatment destroyed the structure of lignocellulose pretreatment, separation of alkaline hydrogen peroxide and obtained high purity stromatin and wood rich in cellulose. The results show that, compared with the steam explosion pretreatment after CO grinding lignin, the lignin has low molecular weight, narrow dispersion, low content of phenolic hydroxyl value and low S/G value using. The lignin NMR was characterized, compared with the steam explosion of MWL, effect of composition and structure unit for lignin has mild alkaline peroxide treatment process, performance after alkaline peroxide treatment, beta -O-4 lignin structural unit in the beta, beta and beta -5 content high. In addition, after CO pretreatment of glucose residue the rate increased to 91.69%, this is because you can isolate a large number of lignin and hemicellulose synergistic pretreatment process, to get the matrix of high crystallinity and specific surface area rich in cellulose. Synergistic pretreatment process of the pretreatment process is an environment friendly, obtained high purity of lignin and cellulose rich matrix at the same time, it provides an effective way for Eucommia timber into biological materials and bio ethanol based on bio refining. The collaborative process from Eucommia wood hydrolysis pretreatment and activated carbon, through different conditions can be obtained from hydrolysis pretreatment of xylo oligosaccharides (XOS, 1.5-34.4%) and the degradation of hemicellulose, the subsequent activation of high performance activated carbon production process and a small amount of non condensable gas. The results show that based on the based on the 100 kg Eucommia wood, since the optimum conditions of hydrolysis pretreatment (at 170 1H), then activated carbon (50%H3PO4550 C, 120 min) since the coordination process of hydrolysis of the matrix, you can get 10.37 kg xylooligosaccharides, 1.39 kg hemicellulose degradation products, other products from hemicellulose and 17.29 kg 40.72 kg activated carbon (SBET 1534.06 m2/g). Among them, AC170-1.0 in all active carbon in the sample surface area is the highest. At the same time, produced from the best comprehensive in the process of non condensable gas (29.14 kg) than from direct carbon activation Daniel (68.84 kg) significantly decreased the yield. In addition, show that the best activated carbon samples by catalytic decomposition of methane hydrogen production experiment (AC170-1.0) has good catalytic activity and high stability. Overall, comprehensive process of bio refining based on both carbon xylo oligosaccharide and high performance activity of better quality, which can effectively improve the pyrolysis the wood industry of Eucommia added value and the prospect of industrial application.

【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S567.19
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本文编号：1417191