反胶团萃取蛋白质的平衡模型：静电和疏水性作用的贡献

研究了二(2-乙基己基)琥珀酸酯磺酸钠(AOT)和四聚氧乙烯基苯壬基酚醚(PNE4)混合表面活性剂反胶团系统萃取溶菌酶的平衡行为,建立了考虑静电作用和疏水性作用贡献的反胶团萃取蛋白质的分配平衡模型,实验验证了模型的可靠性和适用性. 研究发现,有Na⁺存在时AOT的疏水性较K⁺存在时小,而PNE4的疏水性因子与盐离子种类无关;Na⁺对溶菌酶表面疏水性的增大效应较K⁺显著;K⁺在反胶团内界面上的吸附作用大于Na⁺. 利用静电学和热力学理论讨论和解释了有关现象.     

TRPO-AOT/异辛烷反胶团体系萃取细胞色素C和牛血红蛋白

将中性磷氧萃取剂与阴离子型表面活性剂混合溶解在异辛烷中，形成混合反胶团，萃取蛋白质结果表明，该体系对分子量较小的细胞色素Ｃ及分子量较大的牛血红蛋白的萃取性能均比单一反胶团体系更好，萃取曲线均呈“钟”形与单一反胶团相比，混合反胶团中的牛血红蛋白更易被反萃，而细胞色素Ｃ难被反萃，所以，混合反胶团体系更适合于分离纯化牛血红蛋白有机相乳化及温度对混合体系萃取蛋白质性能有较大的影响此外，混合反胶团比单一反胶团大，它们的形貌均为球形     

反胶团萃取蛋白质特性的研究

实验将一种阴离子表面活性剂（AOT）和一种阳离子表面活性剂（Aliquat336）分别溶于异辛烷（isooctane）中，构成了两种不同的反胶团体系．通过用两种不同的反胶团溶液萃取六种蛋白质的实验，研究了水相pH值及离子强度对反胶团体系中水含量Wo和蛋白质萃取率影响的规律．实验发现不论哪种反胶团体系，水相pH值对Wo的影响都不大，但pH值却对蛋白质萃取率有很大的影响，对AOT反胶团体系而言，随着pH值的降低，蛋白质的萃取率升高；对Aliquat336反胶团体系而言，随着水相pH值的降低，蛋白质的萃取率下降．随着离子强度的增大，AOT反胶团体系的水含量大幅度地降低；而对Aliquat336体系水含量的影响很小，但水相离子强度对蛋白质萃取率的影响是相同的，随着离子强度的增大，两种体系对蛋白质的萃取率均下降。     

阳离子反胶团体系萃取牛血清白蛋白

采用一种新的阳离子反胶团体系(CTAB/异辛烷-正戊醇),研究了反胶团萃取牛血清白蛋白(BSA).用单变量法考察了表面活性剂浓度、水相pH值、离子种类和浓度、萃取时搅拌速率和油水比对BSA萃取率的影响.实验表明,静电作用力是该萃取过程的主要动力,随水相pH值增大,BSA的萃取率逐渐升高;对于不同种类的离子,基本随其浓度增大,萃取率下降.在优化的操作条件下,BSA萃取率可达98%以上,因此,CTAB/异辛烷-正戊醇反胶团体系适合BSA的萃取.     

聚合物反胶团萃取生物活性酶的研究

利用三嵌段聚合物形成的聚合物反胶团进行了萃取生物活性酶的研究,确定了最佳的实验体系.考察了聚合物种类和浓度、助表面活性剂浓度、pH值、温度以及盐浓度等对溶菌酶、胰蛋白酶和α-淀粉酶萃取的影响,为今后在该领域的研究提供了依据.     

不同类型反胶团萃取细胞色素C的研究

以细胞色素 C为研究对象 ,研究了水相 p H值、离子强度、相体积比、表面活性剂浓度和类型及萃取时间对反胶团法萃取细胞色素 C的影响 ;讨论了不同类型反胶团体系的萃取机理。结果表明 ,反胶团法的提取率高 ,且高效、快速、简便。选择合适的体系和条件 ,可以实现细胞色素 C的有效萃取     

反胶团萃取分离地木耳中藻蓝蛋白

采用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)反胶团萃取分离地木耳中藻蓝蛋白。分别考察水相pH值、离子强度和种类、有机相中有机溶剂配比、表面活性剂浓度和助溶剂浓度对萃取行为的影响;同时采用正交试验法,考察反萃取过程中反萃液种类、浓度和pH值对萃取液中藻蓝蛋白反萃取行为的影响,最终得到适宜的萃取分离工艺条件。结果表明:0.05mol/LCTAB/正己醇-正辛烷(体积比1∶4)的反胶团体系用于萃取pH=7的地木耳细胞破碎液,藻蓝蛋白萃取率可达98.1%,分配系数达到50.7;溶液中不同离子种类和强度对萃取率影响不同,萃取率随着离子强度增大而降低;采用pH=4.0、3mol/LKBr反萃液反萃藻蓝蛋白,反萃率可达98.5%,其纯度可达16.8。     

SEPES/异辛烷反胶团中脂肪酶的特性

<正>反胶团酶反应兼有水相与有机相酶反应的共同优点,但至今尚无工业应用的重要原因是反胶团中酶的活性和稳定性不高.常用的离子型表面活性剂,如二-(2-乙基己基)琥珀酸双酯磺酸钠(AOT)在有机溶剂中形成的反胶团,因相界面与酶分子间的静电作用将造成酶在反胶团中迅速失活.而非离子型表面活性剂形成的反胶团中,酶一般具有较高的活性和稳定性,但这种体系需加入助表面活性剂,给下游加工过程带来麻烦.作者制备了具有不同氧乙烯聚合数(n)的二-(2-乙基己基聚氧乙烯)琥珀酸双酯磺酸钠(简称SEPES),其分子结构与AOT相似,但其极性头与疏水尾间连有聚氧乙烯链非离子性亲水基团.本文报道脂肪酶在SEPES/异辛烷反胶团体系中的特性.     

反胶团系统及蛋白质萃取过程研究进展

综述了反胶团系统和蛋白质萃取过程,将反胶团萃取系统按单一反胶团系统、混合反胶团系统和亲和反胶团系统划分,强调了研究开发生物相容性表面活性剂以及在反胶团系统中引入亲和作用的重要性。另外,指出了深入开展反胶团萃取设备和过程研究的必要性。     

基于表面活性剂的反胶团萃取技术

基于表面活性剂的反胶团萃取技术是一种新型的有发展前途的生物分离技术。介绍了反胶团萃取技术的驱动力、表面活性剂选择和影响因素,提出了反胶团萃取技术目前存在的问题,探讨了反胶团萃取技术在其酶促反应和纳米材料制备方面的应用及其发展方向。     

Acquisition of Water Solubility Diagrams in Ternary Systems (AOT/Organic Solvent/Alcohol) and Extraction of α-Lactalbumin Using Reverse Micellar Systems

In this study water solubility curves were constructed and calorimetric measurements obtained for reverse micellar systems consisting of an alcohol (isopropanol or butanol), surfactant (AOT) and organic solvent (isooctane or hexane). Also evaluated were the effects of alcohol and solvent type and surfactant concentration on the extraction of the α-lactalbumin (α–la). From the obtained solubility diagrams for ternary systems, it was concluded that isooctane presented the highest water solubility capacity in the center of the micelle systems with hexane, since isooctane has greater molecular volume and greater effect of the surfactant aggregation number. With respect to the alcohols, it was observed that isopropanol and butanol act in the system as a co-surfactant, since they prefer to adsorb at the water/solvent interface. It was also verified that butanol improved water solubility inside the reverse micellar due to its contribution to increase the critical packing parameter. The amount of α-la extracted increased proportionally with the AOT concentration for systems with isooctane and hexane. However, for systems with the latter solvent, the concentration of extracted protein first increases and then decreases. The extraction power of reverse micellar systems with isooctane was influenced by the type of alcohol with butanol showing better results. For systems containing hexane there was no effect of the alcohol added to the system on extraction power of α-lactalbumin.     

Enzymatic activity of Chromobacterium viscosum lipase in an AOT/Tween 85 mixed reverse micellar system

To enhance the Chromobacterium viscosum lipase (glycerol‐ester hydrolase; EC 3.1.1.3) activity for the reaction of water‐insoluble substrates, the AOT/isooctane reverse micellar interface was modified by co‐adsorption of a non‐ionic surfactant. Polyoxyethylene sorbitan trioleate (Tween 85) was used as the non‐ionic surfactant and olive oil as a water‐insoluble substrate. An appreciable increase of lipase activity was observed and at higher W_o values (where W_o = molar ratio of water to total surfactants of the micellar system) there was no sharp fall of the enzyme activity such as a typical bell‐shaped profile. The kinetic model for the lipase‐catalysed hydrolysis of olive oil in AOT/isooctane reverse micellar system was applied to the enzymatic reaction in this mixed reverse micellar system. It was found that the predictions of the model agree well with the experimental kinetic results and that the adsorption equilibrium constant of olive oil molecules between the micellar phase and the bulk phase of the organic solvent is smaller in AOT/Tween 85 mixed reverse micellar systems than in simple AOT reverse micellar systems. © 1999 Society of Chemical Industry     

Increased activity of Chromobacterium viscosum lipase in AOT reverse micelles in the presence of short chain methoxypolyethylene glycol

The activity of Chromobacterium viscosum lipase (glycerol‐ester hydrolase, EC 3.1.1.3) entrapped in AOT/isooctane and AOT/Tween 85/isooctane reverse micelles was significantly increased by the addition of short chain methoxypolyethylene glycols (MPEGs), taking the hydrolysis of olive oil as a model reaction. The molecular weight of MPEG had a strong effect on the lipase activity, and MPEG of nominal molecular weight 550 was found to be the most effective. To optimize the factors affecting enzymatic hydrolysis of olive oil in reverse micellar systems containing MPEG 550, the effect of various parameters, such as W_o (molar ratio of water to surfactant), pH, ionic strength, surfactant concentration and temperature were investigated. A kinetic model considering the substrate adsorption equilibrium between the bulk phase of organic solvent and the micellar phase was also successfully used to understand the enzyme activity in the presence of MPEG 550. Both the Michaelis constant and the substrate adsorption equilibrium constant were obviously reduced as compared with those obtained in the simple AOT reverse micellar system. © 2001 Society of Chemical Industry     

Fabrication and Characterization of Gradient Refractive Index Plastic Rods Containing Inorganic Nanoparticles

A novel method was developed for the preparation of GRIN plastic rods containing inorganic nanoparticles. Silver nanoparticles were prepared by using W/O (water in oil) reversed micelle technique in the presence of bis(2-ethylhexyl) sulpho-succinate (AOT) surfactant. The effects of w values (w=[H₂O]/[AOT]), silver nitrate concentration, AOT/isooctane/H₂O ratio, and initiator concentration on the nanoparticle size were investigated. Optical absorption spectra of the micellar samples were recorded on a spectrophotometer at room temperature in the range of 200–900 nm. The nanoparticle size was confirmed by TEM technique. To introduce the nanoparticles into the GRIN plastic rods, methyl methacrylate (MMA) was used instead of isooctane in the organic phase. Nanoparticles were found to increase the refractive index of plastic rods effectively. However, the existence of surfactant may cause the aggregation of nanoparticles leading to the occurrence of light scattering and becoming opaque. We estimated both real image transmission and the three dimensional refractive index distributions of the GRIN plastic rods prepared in this investigation. The results in this investigation suggest that nanoparticles could be used as a dopant to fabricate GRIN plastic rods and increase its refractive index effectively.     

Forward and Backward Extraction of Methylene Blue by using AOT/Isooctane Reversed Micellar Solution

Organic dyes, which are contained in industrial effluents, should be removed to avoid health hazards and destruction of the ecosystem. In this study, the extraction of methylene blue from aqueous solution into AOT/isooctane reversed micellar solution was investigated. It was found that methylene blue was solubilized into the waterpool within reversed micelles by electrostatic interaction with AOT. The extraction ratio of methylene blue increased with an increase in AOT concentration and a decrease in salt concentration. The methylene blue extracted reversed micelles could be recovered into fresh salt solution with high concentration. It is considered that the main driving force of forward and backward extraction of methylene blue is electrostatic interaction between cationic dye, methylene blue, and anionic surfactant, AOT. The deterioration of the forward and backward extraction behavior by using AOT/isooctane reversed micellar solution reused was not observed.     

酶促木质素与酚聚合反应分子量及分布实验

在反相微乳液系统中 ,进行了过氧化物酶催化木质素与酚共聚反应实验 ,考察了酶浓度、WO(水 /表面活性剂 ,质量比 )、表面活性剂浓度、单体 (酚、木质素 )浓度及醇烃比对聚合物分子量的影响。结果表明 ,聚合物重均分子量可用表面活性剂浓度、酶浓度、单体浓度及油相中醇烃比来调控。用单纯形优化法关联了实验数据 ,得到了聚合物重均分子量的关联式 :M =6 2 7× 10 4 (Y1× 10 7) -0 .3 4Y0 .982 Y0 .83 Y2 .4 64 Y1.0 55。聚合物分子量分布出现双峰 ,是两种反应机理竞争的结果。     

Enhanced Solvent Extraction with Water-in-Ok Microemulsions

Abstract

This paper examines theoretically the conditions which favor enhanced extraction when a microemulsion phase containing a surfactant and a chelating agent is used as the solvent extraction organic phase. A general thermodynamic model of liquid-liquid distribution in reversed micellar systems is presented. The model treats the reversed micellar aggregates of the surfactant HA as a pseudophase and considers (a) the partition of a chelating extractant (HL) between the continuous organic phase and the reversed micellar pseudophase, (b) transfer of the metal ion M^z+ into the continuous organic phase via reaction with HA monomers, (c) partition of the M^z+-HA complex between the continuous organic phase and the reversed micellar pseudophase, (d) reaction of the M^z+ -HA complex with HL in the reversed micellar pseudophase, and (e) partition of the HL-containing complex between the reversed micellar pseudophase and the continuous organic phase. Quantitative expressions are derived that permit one to identify the chemical parameters that influence the liquid-liquid transfer process and therefore permit one to undertake the rational design of microemulsion formulations for specific applications.     

反胶束萃取牛血清白蛋白

研究了ＣＴＡＢ－正己醇－正辛烷反胶束溶液萃取ＢＳＡ的性能。考察了水相的ｐＨ值与离子强度和种类、有机相中表面活性剂浓度和助溶剂浓度等因素对萃取行为的影响，并从反胶束的微观结构予以解释。