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.     

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。     

新型混合反胶团萃取溶菌酶的平衡行为

研究了由阴离子表面活性剂二-(2-乙基己基)琥珀酸酯磺酸钠(AOT)和非离子表面活性剂聚氧乙烯基(聚合度为4)壬基酚醚(OPE4)组成的一种新型混合反胶团体系及其萃取溶菌酶的平衡行为. 结果表明,该反胶团体系具有较大的含水量,且其含水量在较大的表面活性剂配比(0~0.8)范围内维持恒定,是由静电作用和胶束形态改变共同作用的结果. 无机盐种类和离子强度对上述混合反胶团的含水量有着显著的影响,继而影响到溶菌酶的萃取率. 它可归结为盐离子对扩散双电层和水化膜斥力的因素所致. 降低pH和提高总表面活性剂浓度均有利于溶菌酶的萃取.     

提纯工业级α-淀粉酶:反胶团萃取的一个实际应用

实验研究了使用阳离子表面活性剂Aliquat336与异辛烷构成的反胶团溶液，通过液－液萃取方式纯化工业级α-淀粉酶的过程．当使用的反胶团溶液组成为Aliquat336／isooctane／1％（V／V）n－butanol时，实验发现纯化工业级α-淀粉酶的最佳条件：水相组成为30mmol／L，pH10，或酶，萃取时间为1min；反萃液组成为30mmol／L，pH6，反萃时间为3min在此条件下，通过萃取循环能够达到纯化工业级α-淀粉酶的目的，经过一个萃取与反萃循环后，α-淀粉酶的比活提高1．5倍，酶活回收率达85％与此同时，工业级α-淀粉酶中所含的中性蛋白酶活回收率只有10％，而且其比活降低了近7倍。α-淀粉酶与中性蛋白酶间的分离系数能达10左右．     

C_12-2-C_12·2Br反胶团萃取胰蛋白酶的研究

研究了C12-2-C12·2Br/正庚烷/正己醇溶液所形成的反胶团体系对胰蛋白酶的萃取,重点考察了离子强度、水相pH值、表面活性剂浓度、正己醇含量等因素对萃取率的影响。结果表明,最佳萃取条件为:KCl浓度为0.1mol/L,水相p H为12,C12-2-C12·2Br浓度为8mmol/L,正己醇与正庚烷的体积比为0.21。胰蛋白酶的萃取率可达81%。     

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     

反胶团法萃取分离L-亮氨酸的研究

考察了表面活性剂2-乙基已基琥珀酸酯磺酸钠(AOT)浓度、无机盐种类和浓度、温度、盐酸浓度、L-亮氨酸质量浓度以及萃取时间对AOT/异辛烷/H2O反胶团体系萃取分离L-亮氨酸的影响.结果表明:AOT反胶团对L-亮氨酸的萃取在30 min左右即达到平衡,且其萃取率随油相中AOT浓度的增大而升高,随水相中氯化钠、氯化钙、氯化钾浓度的增大而减小;水相盐酸浓度、L-亮氨酸浓度过高均不利于其萃取分离;温度对其萃取反应的影响不大.     

AOT-磷脂反胶团体系萃取蛋白质的研究

研究了PC/AOT和PE/AOT混合体系在有机溶剂中形成反胶团的性质及其萃取蛋白质的性能,并解决了反胶团萃取中有磷脂存在时的蛋白质浓度的分析问题.研究结果表明,在AOT体系中加入磷脂能使胶团尺寸变大,且加入PE能提高血红蛋白和枯草杆菌a—淀粉酶的萃取率,加入PC则常使萃取性能变差.因此,在反胶团萃取蛋白质时,影响萃取的主要因素不仅是胶团的大小,还有胶团与蛋白质之间的相互作用.     

反向微胶团萃取氯基酸的研究

研究以二－（２－乙基己基）磷酸铵为表面活性剂所形成的反向微胶团对氨基酸的萃取，结果表明，表面活性剂浓度，水相溶液的ＰＨ值及离子强度对氨基酸萃取的分配比有重要影响。     

离子液体反胶团中青霉素酰化酶的水解反应特性

反胶团是表面活性剂在非极性溶剂中自聚形成的微观结构．其亲水头部朝内,疏水尾部朝外,形成可容纳极性溶质的水相空腔,在蛋白质萃取及酶催化方面得到广泛研究．对于用青霉素酰化酶水解青霉素生产6-氨基青霉烷酸（6-APA）的工艺,反胶团兼具高效性与分离便利的优点Ⅲ．目前反胶团的调控主要集中在水含量、pH值与阴离子类型等方面,对表面活性剂头部的作用还缺乏了解．     

Liquid-Liquid Extraction of Low Molecular-Weight Proteins by Selective Solubilization in Reversed Micelles

Abstract

The effects of pH and salt concentration on the solubilization of ribonuclease-a, cytochrome-c and lysozyme in Aerosol OT/isooctane reversed micelle solutions have been studied to explore the potential for employing this solvent system in the large-scale recovery and concentration of proteins using liquid extraction. For pH values below the isoelectric point, pI, of the protein, solubilization was high, probably owing to strong electrostatic-interactions between the positively charged proteins and the anionic surfactant heads forming the inner micelle wall. Above the pI, the proteins could not be solubilized, probably because of unfavorable electrostatic repulsions between the like-charged proteins and surfactants. At low ionic strength and neutral pH, complete solubilization of the proteins was observed. As the ionic strength was increased, there was an abrupt decrease in solubilizing power of the reversed micelle solutions; the salt concentration at which this occurred was different for each protein. A mixture of the three proteins was cleanly resolved using a single extraction step and two stripping steps. The conditions in each step were selected according to the results of the single protein extraction studies.     

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.     

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     

Amino acid solubilization in cationic reversed micelles: factors affecting amino acid and water transfer

The aim of this work is to investigate the driving forces involved in amino acid solubilization in cationic reversed micelles, and to determine in which way different parameters affect the reversed micellar structure and amino acid solubilization, in order to select the best conditions to optimize amino acid extraction. To this end, extraction equilibrium experiments were performed using different experimental conditions and three amino acids with different structures: aspartic acid – a hydrophilic amino acid, phenylalanine – a slightly hydrophobic amino acid, and tryptophan – a hydrophobic amino acid. The study of the effect of amino acid related parameters, such as pH and the initial amino acid concentration in the aqueous phase, and the effect of parameters that influence the reversed micellar structure, such as surfactant concentration, ionic strength and co‐surfactant concentration, provides useful information about the driving forces involved, solute–micelle interfacial interactions and solute location in the cationic system trioctylmethylammonium chloride (TOMAC)/hexanol/n‐heptane. These parameters can be adjusted to optimize amino acid extraction. It is shown that amino acids with the same isoelectric point can be selectively separated by exploring the different interactions they establish with the reversed micellar interface. © 1999 Society of Chemical Industry     

Predispersed solvent extraction of negatively complexed copper from water using colloidal liquid aphron containing a quaternary ammonium salt

Negatively complexed copper ion by complexing agent like EDTA (Ethylenediaminetetraacteic acid) was removed by predispered solvent extraction (PDSE) using colloidal liquid aphrons (CLAs) made out of Trioctylmetylammonium chloride (Aliquat 336) diluted with nonpolar kerosene. PDSE was found to have higher mass transfer rate than conventional solvent extraction under experimental conditions without mechanical mixing. The effect of type of water-soluble surfactants, phase volume ratio (PVR), concentration of anionic Sodium Dodecyl Benzene Sulfonate (SDBS) on PDSE was investigated. In addition, the effect of anionic SDBS on back extraction in PDSE was also studied. Under experimental conditions with enough mechanical mixing, the amount of copper transferred to Aliquat 336 core from the pregnant phase was compared in both PDSE by using anionic SDBS and conventional solvent extraction. It is concluded that PDSE using Aliquat 336 CLA can be used for treatment of negatively complexed copper without the influence of surfactant. To optimize CLAs-based process, stability of CLAs containing a quaternary ammonium salt Aliquat 336 diluted with kerosene in the continuous phase was investigated by measuring the volume released to surface. To destabilize CLAs, H⁺, OIL were added. Stability of CLAs was estimated by comparing the half-life obtained. Break-up of destabilization follows pseudo-first-order reaction kinetics at low ionic strength. But, pseudo-first-order model cannot be applied to a region of high ionic strength.     

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     

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     

亲和反胶团选择性萃取分离酵母乙醇脱氢酶

The reversed micelles were formed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant and n-hexanol as cosolvent in the CTAB (50mmol L-1)/hexanol (15% by volume)/hexane system. Cibacron Blue 3GA (CB) as an affinity ligand in the aqueous phase was directly introduced to the reversed micelles with electrostatic interaction between anionic CB and cationic surfactant. High molecular weight (Mr) protein, yeast alcohol dehydrogenase (YADH, Mr = 141000) from baker's yeast, has been purified using the affinity reversed micelles by the phase transfer method. Various parameters, such as CB concentration, pH and ionic strength, on YADH forward and backward transfer were studied. YADH can be transferred into and out from the reversed micelles under mild conditions (only by regulation of solution pH and salt concentration) with the successful recovery of most YADH activity. Both forward and backward extractions occurred when the aqueous phase pH>pI with electrostatic attraction between YADH and CTAB. Th     

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。