【作者】 郭诤；

【导师】 孙彦；

【作者基本信息】 天津大学 ， 生物化工， 2004， 博士

【摘要】 以国产红花油为原料开发了一个具有工业应用潜力的制备高纯度亚油酸的新工艺，一次纯化可获得纯度在98%以上、产率48%以上的亚油酸。通过碱催化共轭化获得了共轭亚油酸(CLA)总含量达97%、活性异构体含量大于90%的产品，并利用GC-FTIR和GC-MS对CLA主要异构体的结构进行了鉴定。设计了一套制备高纯度1,3-二共轭亚油酰甘油的无溶剂反应体系，该体系以Novozym 435为催化剂通过真空氮气搅拌操作于45-60℃、反应2-4小时可获得纯度高达92%-98%的1,3-dCLG产品。利用该反应体系实现了通过在线测量水活度变化对反应进程的监测。利用响应面法对Novozym 435催化1,3-dCLG合成的反应条件进行了优化，建立了优化模型。通过实验验证了模型的有效性，利用模型优化的条件成功地进行了放大试验，表明该技术具有潜在的工业应用价值。以Novozym 435为催化剂实现了高纯度共轭亚油酸三酰甘油(tCLG)的无溶剂合成。该工艺具有潜在的工业应用价值，据估算，1kg的Novozym 435可以催化合成128-190kg的tCLG含量为95-98%的高附加值的tCLG产品。开发了一种新型包覆油酸稳定化磁性纳米粒子的聚乙酸乙烯酯-苯乙烯(VAc-DVB) 疏水磁性微球。利用环境扫描电镜、透射电镜和振动探针式磁强仪等多种手段对载体进行了表征。结果表明，其磁学行为可以用Langevin方程描述，微球具有超顺磁性。微球具有很强的磁响应性和良好的重新分散性能。疏水磁性微球的脂肪酶（CCL）固定化活性负载量高达每克载体6750 IU。疏水磁性微球固定化脂肪酶具有良好的热稳定性和持续使用性能，且其橄榄油水解活性高于游离酶，表明发生了“界面活化”作用。固定于超顺磁疏水聚VAc-DVB微球上的脂肪酶在log P= 2-4的疏水介质中的催化酯化活性是游离酶的2-3倍。首次观察到酶的活性随混合互溶有机介质的log P值的增加呈指数增长。对无溶剂多元竞争反应体系中酶对醇选择性的实验研究表明，酶对醇的酯化选择性存在强烈的链长依赖性；且受到与其酯化的酰基供体性质的影响；固定于疏水载体上的脂肪酶对长链醇的选择性增加。更多还原

【Abstract】 A new procedure for the preparation of high-purity linoleic acid from native safflower oil was developed, and the method was shown to possess industrial application potentials. The linoleic acid product with a purity of higher than 98% was obtained with overall yield of higher than 48%. The products with total conjugated linoleic acid (CLA) content of 97% and biologically active isomer content of higher than 90% were achieved by alkali-catalyzed conjugation of high-purity linoleic acid under optimized conditions. The major isomers were identified by the GC-FTIR and GC-MS analysis of the products. A solvent-free reaction system for the preparation of high-purity 1,3-diconjugated linoleoyl glycerol (1,3-dCLG) was designed. The reaction was conducted for 2-4 h using Novozym 435 as biocatalyst with N2 stirring under vacuum at 45-60 °C, and the 1,3-dCLG product of 92-98% purity was produced. In this reaction system, the evolution of esterification was monitored by the detection of the water activity over the reaction mixture. The response surface methodology (RSM) was employed to optimize the reaction conditions for the Novozym 435 catalyzed synthesis of 1,3-dCLG, and the best fitting models were established. The efficiency of the model was experimentally verified. A scale-up experiment was successfully performed based on the optimized condition, indicating the industrial potentials of the technology.Solvent-free synthesis of high-purity triconjugated linoleoyl glycerol (tCLG) employing Novozym 435 as biocatalyst was performed. And this reaction design was shown to possess industrial application values. It’s estimated that 128-190 kg tCLG products of 95-98% purity with high extra value could be produced by the reaction design employing 1 kg Novozym 435. A novel hydrophobic magnetic microsphere encapsulating oleic acid-stabilized nano-sized magnetic particles was developed for lipase immobilization. Environmental scanning electron microscope, transmission electron microscope and sample vibrating magnetometer etc. were employed to characterize the carrier. The results indicated that the magnetic behavior of the microspheres could be described by Langevin equation and was proved to be superparamagnetic. The carrier has strong <WP=5>responsiveness and good redispersion in many media. Candida rugosa lipase (CRL) was immobilized to the porous carrier at up to 6750 IU/g carrier, remarkably higher than the previous studies. The immobilized CCL showed enhanced thermal stability and good durability in the repeated use after recovered by magnetic separations. Activity amelioration of the immobilized CRL in the hydrolysis of olive oil indicated an “interfacial activation” after immobilization.The activity of the immobilized lipase adsorbed on hydrophobic and superparamagnetic microspheres was 2 to 3-fold higher than that of the native one in catalyzing esterification in hydrophobic solvents (log P, 2-4). Exponentially increasing curves of the activity of the immobilized and native lipases against the hydrophobicity (log P) spectrums in mixed two miscible solvents were firstly observed. A solvent-free multiple-competitive reaction was designed to examine the alcohol specificity of the lipases and revealed that the alcohol specificities of the lipases had a strong chain-length dependency. Moreover, this work showed that alcohol specificity of the lipases was influenced by the nature of acyl donors, and the lipase became more preferential for longer-chain alcohol after immobilization on the hydrophobic microspheres.更多还原