发酵液中L-色氨酸分离纯化工艺研究

通过静态吸附实验,考察了温度、pH值对001×7阳离子交换树脂平衡吸附量的影响,并测定了吸附动力学曲线。通过动态实验,测定了动态吸附曲线和洗脱曲线。最后确定了001×7阳离子交换树脂分离纯化L-色氨酸的最佳工艺条件:用001×7阳离子交换树脂吸附L-色氨酸,以浓度为2 mol.L-1氨水进行洗脱,收集的流份经D315阴离子交换树脂脱色,浓缩结晶后得L-色氨酸成品,总提取率为73.0%。     

黑果枸杞色素的提取和精制工艺研究

本文采用正交实验法对黑果枸杞色素的提取和精制工艺进行了研究。结果表明,黑果枸杞色素的最佳提取条件为:以pH 3.0的80%乙醇作浸提剂,提取温度50℃,提取时间3 h,固液配比1:40;用X-5大孔吸附树脂对色素进行精制,以树脂柱径高比1:15、流速3 mL/minp、H 3.0、色素液浓度1 g/L为最佳吸附条件,色素的吸附量可达0.03715 g/mL湿树脂体积;而以95%乙醇做洗脱液,在pH 2.0、流速5 mL/min、3倍于柱床体积的洗脱液条件下解吸附效果最佳,色素回收率达到97.78%;制取的色素产品外观呈紫红色,色价为36.7。     

离子交换法在L-精氨酸发酵生产提取工艺中的应用研究

在发酵生产L-精氢酸的提取工艺中,对提取总收率影响较大的离子交换工艺进行了研究。结果表明,用国产强酸性001×7树脂对发酵液中的L-精氨酸进行动态交换吸附,当上柱流速控制在1/50vvm条件下,其交换量为1.135meq/ml湿树脂。用2.5mol/L氨水洗脱,流速控制在1/50vvm时,其洗脱效果最好。用国产201×4树脂进行脱色,每10ml树脂可脱色160ml以上的洗脱液,透光度大于90%,几乎不发生交换吸附L-精氨酸的现象。离子交换工序收率大于95%。     

离子交换吸附L-瓜氨酸的热力学和动力学

研究不同树脂对L-瓜氨酸的吸附能力,发现D001树脂对L-瓜氨酸的吸附效果最好。采用静态吸附法研究L-瓜氨酸在D001型阳离子交换树脂上的热力学和动力学特性,考察不同温度、pH和溶液初始浓度对离子交换过程的影响。结果表明:L-瓜氨酸在D001型阳离子交换树脂上的吸附等温线符合Freundlich和Langmuir等温吸附方程,其中,Langmuir吸附方程能更好地描述该过程。吸附过程焓变ΔH=-45.01 k J/mol(0),说明该吸附过程放热。树脂对L-瓜氨酸的吸附过程速度控制步骤为颗粒扩散。随着温度升高,树脂的最大平衡吸附量减小;当pH=6时,树脂达到最大吸附量135.5 mg/g;L-瓜氨酸溶液初始质量浓度为8 g/L时,扩散系数达到最大,为8.53×10-3,吸附速率最快。     

树脂交换基的型式和上柱液的pH 对精氨酸生产的影响

<正> 树脂交换基的型式和上柱液的 pH 对氨基酸的分离有着十分重要的影响,根据资料报道,强酸性阳离子交换树脂的交换基为游离酸型如 H~+是其交换基时,全部氨基酸均可以进行交换吸附;交换基为盐型如 Na~+、NH_4~+是其交换基时,且上柱液的 pH 又在中性或微碱性时,只有碱性氨基酸可以进行交换吸附。但是,对于猪毛酸水解,提取胱氨酸后 pH4.8母液中精氨酸的生产,树脂交换基采用何种型式阳上柱液的 pH 以多少为最合适呢?为此,我们将732树脂处理成 H~+、Na~+、NH_4~+三种型式和调上柱液的 pH4.8、6.5,进行了精氨酸纯度和产量测定,我们又用稀氨水洗脱,绘制了精氨酸洗脱曲线。     

大孔树脂分离纯化“黑金刚”紫马铃薯花青苷工艺研究

以紫色马铃薯"黑金刚"花青苷为原料,采用D101、HDP100A、HDP450A、NK-9、AB-8五种大孔吸附树脂对花青苷的吸附与解析特性进行了比较研究,并在此基础上,采用最佳大孔树脂对花青苷纯化过程中的静态、动态吸附和解析附条件进行了优化研究。结果表明AB-8大孔树脂具有较好的吸附和解析能力,是纯化紫色马铃薯花青苷的最佳树脂,较优纯化条件为:上样液花青苷浓度为0.028mg.g-1,上样液pH=2,洗脱液乙醇浓度为50%,洗脱液pH=1,吸附流速为1mL.min-1,洗脱流速为1mL.min-1。经大孔树脂纯化后,色价值比纯化前提高了7.55倍。     

DM-130树脂对甘草酸的吸附性能及提纯应用研究

探讨了大孔吸附树脂DM-130对甘草酸的吸附性能及原液浓度、pH值、流速对此树脂吸附性能的影响.结果表明,DM-130树脂对甘草酸的吸附性能好,易于洗脱,分离效果好,产品纯度可达94.676%;正交试验表明,pH为5.4±,原液浓度为10 mg/ml,以2 BV/h的流速为最佳处理;洗脱液采用3 BV 10%的乙醇最经济.     

大孔树脂纯化卫矛总黄酮的工艺研究

筛选纯化卫矛总黄酮的最佳大孔树脂及其最佳工艺条件,采用正交设计法考察树脂种类、洗脱液浓度、pH值等因素对纯化的影响。用紫外分光光度法测定总黄酮的含量,计算吸附量、解吸率和浸膏总黄酮含量,最后确定最佳工艺条件。AB-8树脂最适于纯化卫矛总黄酮;最佳吸附量和解吸率分别是7.32 mg·g^-1和90.98%;浸膏的总黄酮含量从7.64%提高到了52.12%。该树脂可以用于精制卫矛总黄酮,提高提取物中总黄酮的含量。     

HD-8树脂分离天花粉中的L-瓜氨酸

本文研究了用HD8阳离子交换树脂从天花粉中分离L瓜氨酸的工艺条件。采用HD8阳离子交换树脂从天花粉水提取液中交换L瓜氨酸,该树脂对L瓜氨酸的静态交换容量为50.8mg·mL1。在流速为3BV·h1,提取液中L瓜氨酸浓度为9.64mg·mL1时,HD8树脂对L瓜氨酸的动态交换容量为46.8mg·mL1树脂,其动态平衡时间为12min。NH4OH洗脱HD8树脂载荷的L瓜氨酸效果好。控制洗脱液流速为5BV·h1,用8BV0.25mol·L1的NH4OH即可完全洗脱L瓜氨酸。采用HZ803大孔径吸附树脂吸附L瓜氨酸洗脱液中的色素,真空浓缩,并在pH=5.97、4℃条件下结晶L瓜氨酸,其收得率为7.24%,其中L瓜氨酸含量为82.7%。与等电点法相比,产品纯度提高2.36倍。     

阳离子交换树脂对甜菜碱的吸附特性研究

目的：阐明阳离子交换树脂吸附甜菜碱的机理和特性,获得从甜菜废糖蜜中提取分离甜菜碱的工艺路线。方法：采用雷氏盐比色法测定甜菜碱含量,根据吸附等温线的图形拟合方程。结果：阳离子交换树脂吸附甜菜碱是指数型的吸附等温线类型,并且可以与Freundlich方程很好地拟合。采用阳离子交换树脂从废糖蜜中分离甜菜碱,树脂动态吸附量最大为40mg/ml,吸附流速为40ml/min,盐酸洗脱浓度为1.5mol/L,洗脱速度为30ml/min进行解吸时,解吸率为33%,甜菜碱提取率为58%。结论：阳离子交换树脂吸附甜菜碱的特性为从废糖蜜中提取分离甜菜碱提供了理论依据,使工艺操作简单、易行。     

Prediction of the pH dependence of the separation of weak electrolytes by ion-exchange: Amino acid chromatography with competitive buffer ion eluents

In cation exchange when the sample cations are weak electrolytes, several benefits arise from choosing the eluent cation to be a weak electrolyte with a similar pK. The entire pH buffering range of the eluent can then be practically utilized to effect a modulation of the sample elution volumes. For elution of aliphatic amino acids from sulfonated polystyrene resin using a pyrazolium chloride eluent (pH 4.0 to 1.5) we obtained selectivity coefficients that are independent of pH and ionic strength as well as only weakly dependent on temperature and sample concentration. As a result the sample elution behavior is accurately predictable. The analytical-scale data were used to develop a preparative procedure capable of resolving a sample to resin load 10 times larger than previously reported for amino acid chromatography on laboratory-scale systems.     

1,3‐Propanediol adsorption on a cation exchange resin: Adsorption isotherm,thermodynamics, and mechanistic studies

1,3‐Propanediol (1,3‐PD) is widely used in cosmetics, foods, antifreezes, and polyester. A low‐cost cation exchange resin, 001×7 H‐form resin, was selected for 1,3‐PD adsorption obtained from microbial fermentation of crude glycerol. The thermodynamics and kinetics of adsorption were studied. To identify the characteristics of the adsorption process, the influence of 1,3‐PD concentration, temperature, and resin particle diameters was studied. The temperature dependence of the adsorption equilibrium in the range of 288 to 318 K was observed to satisfy the Langmuir isotherm well. The thermodynamic parameters, adsorption enthalpy, entropy, and Gibbs free energy, were determined as 36.2 kJ·moL^?1, 160 mol^?1·K^?1, and ?11.2 kJ·moL^?1, respectively, which indicated that the adsorption was spontaneous and endothermic. The adsorption kinetics was accurately represented by the shell progressive model and indicated that the particle diffusion was the rate‐limiting step. Based on the kinetic simulation, the rate constant of exchange (k₀), order reaction (α), and the apparent activation energy reaction (E_a) were obtained as 3.11×10^?3, 0.644, and 11.5 kJ·moL^?1, respectively. This kinetic and thermodynamic analysis of 1,3‐PD recovery presented in this article is also applicable for the separation of other polyols by resin adsorption, which will promote value‐added utilization of glycerol.     

生物法合成β-丙氨酸的分离纯化工艺研究

依据天冬氨酸和β-丙氨酸等电点的差异,采用静态吸附和动态吸附法,筛选适于分离β-丙氨酸的最佳树脂,并研究最佳树脂的吸附动力学和料液pH值、上样液流速,洗脱剂浓度等对β-丙氨酸分离的影响。结果表明:β-丙氨酸吸附的最佳树脂为HZ014,HZ014的静态吸附70 min达到动态平衡,吸附容量为72.92 g.kg-1,吸附率高于90%,最佳料液流速是2 ml.min-1,料液最佳pH为5.0,洗脱剂氨水浓度为4%。     

Manufacture of cellulose nanocrystals by cation exchange resin-catalyzed hydrolysis of cellulose

Cellulose nanocrystals (CNC) were prepared from microcrystalline cellulose (MCC) by hydrolysis with cation exchange resin (NKC-9) or 64% sulfuric acid. The cation exchange resin hydrolysis parameters were optimized by using the Box–Behnken design and response surface methodology. An optimum yield (50.04%) was achieved at a ratio of resin to MCC (w/w) of 10, a temperature of 48 °C and a reaction time of 189 min. Electron microscopy (EM) showed that the diameter of CNCs was about 10–40 nm, and the length was 100–400 nm. Regular short rod-like CNCs were obtained by sulfuric acid hydrolysis, while long and thin crystals of cellulose were obtained with the cation exchange resin. X-ray diffraction (XRD) showed that, compared with MCC, the crystallinity of H₂SO₄-CNC and resin-CNC increased from 72.25% to 77.29% and 84.26%, respectively. The research shows that cation exchange resin-catalyzed hydrolysis of cellulose could be an excellent method for manufacturing of CNC in an environmental-friendly way.     

Isolation of L-theanine from tea solution by cation exchange resin in batch and fixed bed column

L-Theanine, a bioactive compound in tea, was isolated from tea solution using cation exchange resin no.732. The adsorption of L-theanine by cation exchange resin no.732 fit the Langmuir isotherm model and was a monolayer molecular interaction process. Thermodynamic studies revealed that the adsorption of L-theanine by resin no.732 was an exothermic and spontaneous physically driven process. The adsorption capacity was influenced by temperature, initial concentration, and pH. The L-theanine adsorption capacity under conditions at room temperature, pH 4.73, and initial L-theanine concentration 18 g/L was 241.731 ± 3.679 mg/g. The Thomas model was fit to describe the column adsorption data at different flow rates and initial concentrations. The L-theanine adsorbed by resin no.732 could be desorbed by 0.134 mol/L Na₂HPO₄ aqueous solution with a recovery rate of 84.96%. These findings indicate that resin no.732 was a promising material for isolating L-theanine from tea solution.     

用阳离子铵型树脂分离苯丙氨酸

应用铵型阳离子交换树脂分离L 苯丙氨酸 ,确定了溶液在pH 1.0的条件下上铵型柱 ,用 0 .15mol L氨水解析 ,解析液对上柱液的苯丙氨酸收率为 95 %。     

Highly pure 1,3‐propanediol: Separation and purification from crude glycerol‐based fermentation

A new separation and purification process was developed for recovering 1,3‐propanediol (1,3‐PD) from crude glycerol‐based fermentation broth with high purity. The downstream process integrated chitosan flocculation, activated carbon decolorization, fixed bed cation exchange resin adsorption, and vacuum distillation. Breakthrough curves were measured considering the effect of sample concentration, flow rate, temperature, and resin stack height. Yoon–Nelson model was proposed to fit the fixed bed adsorption. The characteristic column parameters were calculated. Optimal condition for adsorption was 1,3‐PD, 30.0 g/L; flow rate, 1.00 mL/min; stacking height, 30.0 cm; and temperature, 298 K. Ethanol‐water (75%, 1 mL/min) was used as eluent to separate 1,3‐PD and glycerol with 95.3% 1,3‐PD elution rate. After vacuum distillation, the overall purity and yield of 1,3‐PD were 99.2% and 80.8% in the purification process, respectively. This is a simple and efficient downstream strategy for 1,3‐PD purification.     

霍山石斛人工种子包埋繁殖体和萌发

以腋芽、原球茎、不定芽为繁殖体, 制作霍山石斛人工种子, 利用正交设计探讨麦芽糖、6-BA/NAA、活性炭、海藻酸钠、离子交换时间五个因素对霍山石斛人工种子萌发的影响; 并对人工种皮的糖分泄漏率以及pH的变化进行测定, 另外对霍山石斛人工种子的贮藏和防腐做了初步研究。结果表明: 麦芽糖是影响霍山石斛人工种子萌发的主要因素, 适宜的处理组合为麦芽糖含量为4%、6-BA/NAA 10:1, 活性炭浓度0.1%, 海藻酸钠浓度4.0%, 将含有繁殖体的此配方溶液滴入2% CaCl2溶液中, 进行离子交换反应, 反应时间10 min。以腋芽, 原球茎, 不定芽为繁殖体的霍山石斛人工种子萌发率分别可达到65.6%、90.1%、75.2%, 萌发后幼苗的存活率分别为16.1%、80.6%和19.1%。4°C下贮藏20 d后, 霍山石斛人工种子以腋芽, 原球茎, 不定芽为繁殖体的萌发率分别为3.3%、10.6%、5.2%。包埋剂加入多菌灵后, 自然条件下萌发率分别可以达到6.8%, 13.8%, 7.9%。     

霍山石斛人工种子包埋繁殖体和萌发

以腋芽、原球茎、不定芽为繁殖体, 制作霍山石斛人工种子, 利用正交设计探讨麦芽糖、6-BA/NAA、活性炭、海藻酸钠、离子交换时间五个因素对霍山石斛人工种子萌发的影响; 并对人工种皮的糖分泄漏率以及pH的变化进行测定, 另外对霍山石斛人工种子的贮藏和防腐做了初步研究。结果表明: 麦芽糖是影响霍山石斛人工种子萌发的主要因素, 适宜的处理组合为麦芽糖含量为4%、6-BA/NAA 10:1, 活性炭浓度0.1%, 海藻酸钠浓度4.0%, 将含有繁殖体的此配方溶液滴入2% CaCl2溶液中, 进行离子交换反应, 反应时间10 min。以腋芽, 原球茎, 不定芽为繁殖体的霍山石斛人工种子萌发率分别可达到65.6%、90.1%、75.2%, 萌发后幼苗的存活率分别为16.1%、80.6%和19.1%。4°C下贮藏20 d后, 霍山石斛人工种子以腋芽, 原球茎, 不定芽为繁殖体的萌发率分别为3.3%、10.6%、5.2%。包埋剂加入多菌灵后, 自然条件下萌发率分别可以达到6.8%, 13.8%, 7.9%。