发酵液中乳酸的盐析萃取

研究了一种利用盐析萃取法分离发酵液中乳酸的新方法. 通过系统考察乳酸在不同盐析萃取体系中的分配规律,发现K2HPO4-甲醇和K2HPO4-乙醇体系适合分离发酵液中的乳酸. 发酵液中乳酸浓度为167 g/L时,采用25%(w) K2HPO4-26%(w)甲醇盐析萃取体系,乳酸的分配系数和回收率分别为4.01和86.0%;采用14%(w) K2HPO4-30%(w)乙醇盐析萃取体系,乳酸的分配系数和回收率分别为3.23和90.6%. 此时上相中残余葡萄糖、菌体和可溶性蛋白的去除率分别达67.3%, 100%和85.9%.     

双水相萃取分离纯化叶黄素

研究了3种萃取叶黄素的双水相体系,即传统的双水相体系聚乙醇/硫酸铵体系和基于与水互溶的有机溶剂的新型双水相萃取体系:乙醇/硫酸铵及乙醇/磷酸氢二钾体系。通过实验确定了最佳双水相萃取体系:乙醇/硫酸铵双水相体系,w(乙醇)=40.17%,w(硫酸铵)=8.98%,最大分配系数为90.83,最大收率为99.88%。乙醇/硫酸铵双水相体系的最佳诱导条件是在25±1℃时超声10min。超声结束后,分液,将富含叶黄素的相浓缩,内含硫酸铵晶体,利用乙醇洗涤硫酸铵晶体,溶解叶黄素,抽滤,将滤液浓缩后干燥,得到叶黄素。叶黄素通过HPLC色谱法进行纯度的测定。     

二元小分子醇/盐双水相体系中磺胺嘧啶的分配行为

在双水相体系研究的基础上,建立了乙醇与正丙醇和硫酸铵形成的二元小分子醇/盐双水相体系萃取磺胺嘧啶的新方法,考察了盐种类和浓度、pH值以及静置时间对磺胺嘧啶分配行为的影响。结果表明,二元小分子醇/盐双水相体系可用于磺胺类抗生素分配行为的研究,体系组成为乙醇与正丙醇体积比例为1∶1,硫酸铵浓度为40%,pH值在4.0～5.0,温度25℃,静置10 h,磺胺嘧啶在该二元双水相体系中的分配系数达33.49,萃取率达96.97%。     

乙醇/碳酸钾双水相萃取盾叶薯蓣发酵液中的2,3-丁二醇

实验考察了乙醇/碳酸钾双水相萃取盾叶薯蓣发酵液中2,3-丁二醇的分配情况,并对其工艺条件进行了优化。结果表明,当乙醇22%(质量)、碳酸钾26%(质量)时,发酵液中2,3-丁二醇的回收率达到最高值97%,此时,乙偶姻和残余还原糖的回收率为97%和87%,菌体和蛋白的去除率分别为99%和94%,而丙酮酸、柠檬酸、苹果酸、延胡索酸和琥珀酸的去除率高达100%,这为2,3-丁二醇的工业分离提供了一种新的技术。     

双水相法回收异戊酰螺旋霉素生产废水中的螺旋霉素

建立了乙醇- K2HPO4双水相体系萃取螺旋霉素的方法,对测得的双水相体系的双节线数据进行拟合,并系统研究了K2HPO4浓度、乙醇浓度、螺旋霉素初始浓度、萃取温度和体系pH对分配系数和萃取率的影响。结果表明,双水相萃取螺旋霉素是自发进行、吸热熵增的过程。当K2HPO4质量分数为20%,乙醇质量分数为16%,萃取温度为25℃,体系pH为9.2~9.5时,分配系数可达36.66以上,萃取率可达97.11%以上。其中,当体系"pH = 9.5" 时,分配系数达到47.52,萃取率达到97.97%。乙醇-K2HPO4双水相体系萃取螺旋霉素的纯化倍数及萃取率高,而且所用成相物质乙醇和K2HPO4可以回收重复使用,避免了二次污染,为处理含螺旋霉素的异戊酰螺旋霉素生产废水提供了新的方法。     

乙醇/硫酸铵双水相体系从丹参粗提液中分离丹酚酸B

采用中心复合设计的响应曲面法优化了乙醇/硫酸铵双水相体系从丹参粗提液中分离丹酚酸B的工艺参数,并对放大效果进行了对比研究。结果表明,在确定pH2.0和30℃的条件下,当硫酸铵和乙醇质量分数分别为20%和29%时,丹酚酸B的分配系数最大为58.7,回收率为97.3%。上相加乙醇脱除硫酸铵,减压浓缩、干燥,丹酚酸B的纯度为57.4%。与小试相比,放大40倍后,分配系数(59.3)、回收率(98.2%)和纯度（58.6%）均无显著差异（p<0.05）。500g丹参,经煮提,双水相萃取,脱硫酸铵,氯仿脱脂,乙酸乙脂萃取,可得26.1g浸膏,丹酚酸B的纯度为78.1%,总回收率为87.0%。因此,双水相萃取可以作为从丹参粗提液中规模分离丹酚酸B的有效手段。     

微波辅助双水相提取盾叶薯蓣中的皂苷成分

采用微波辅助乙醇/硫酸铵双水相体系,从盾叶薯蓣中提取皂苷成分. 实验结果表明,各种皂苷成分可有效地富集于醇相,盾叶新苷、三角叶皂苷、薯蓣皂苷元-葡萄糖三糖苷、薯蓣皂苷元-葡萄糖二糖苷、延龄草次苷的最大分配系数分别达89, 91, 93, 117和153. 微波辅助双水相提取皂苷成分的最佳药材/乙醇质量比为1:21,最佳相组成为乙醇25%(w),硫酸铵19%(w),该条件下的提取率为,总皂苷95.1%,盾叶新苷99.8%,三角叶皂苷97.4%,薯蓣皂苷元-葡萄糖三糖苷97.3%,薯蓣皂苷元-葡萄糖二糖苷86.6%,延龄草次苷63.2%.     

超声辅助异丙醇/(NH_4)_2SO_4双水相体系提取金银花中总黄酮

采用异丙醇/硫酸铵/水构建双水相体系,研究在超声波作用下操作条件对金银花中总黄酮萃取效果的影响。实验结果表明,金银花总黄酮主要分布在上相,双水相体系的组成(异丙醇与硫酸铵的浓度)对萃取效果的影响较大。当异丙醇质量分数为30%、硫酸铵质量分数为25%时,常温下超声处理20min,分配系数为29.4,总黄酮的萃取率为94.8%。     

双水相萃取分离苦参生物碱

用乙醇、聚乙二醇和Triton X-100与硫酸铵等无机盐构建双水相体系,研究了各体系的形成过程与性质及对氧化苦参碱和苦参碱的萃取性能,发现乙醇/硫酸铵双水相体系稳定、分相快、萃取率高,更适合苦参生物碱的萃取;对其萃取条件的优化结果表明,乙醇和硫酸铵分别为38%(w)和18%(w),体系pH值为7.0,30℃下搅拌萃取15 min,氧化苦参碱与苦参碱的分配系数和萃取率分别为4.46和5.10,96.17%和95.74%. 在苦参的水提取液中直接用该体系萃取分离氧化苦参碱、氧化槐果碱、槐定碱、苦参碱及槐果碱5种生物碱,萃取率为91.03%~94.46%,三级错流总萃取率为97.22%~98.78%;该体系用于苦参生物碱的纯化,可显著减小杂质含量,苦参碱含量可提高1倍以上,其焓变DH0和熵变DS0均大于0,且DG0<0,表明萃取过程为吸热熵增的自发过程.     

海参加工液中有效成分的盐析萃取

考察了不同亲水性有机溶剂-无机盐双水相盐析萃取体系对海参加工液中蛋白和多糖的盐析萃取能力. 结果表明,叔丁醇-(NH4)2SO4和乙醇-Na2CO3体系对海参蛋白和多糖有较好的萃取效果,蛋白和多糖以界面沉淀形式分配在上层有机相和下层水相之间. 叔丁醇-(NH4)2SO4体系的最佳工艺条件为：(NH4)2SO4 300 g/L,海参加工液与叔丁醇体积比为1:1.5,室温下萃取,蛋白和多糖的最高回收率分别为99.6%和96.3%;乙醇-Na2CO3体系的最佳工艺条件为：乙醇16%(w), Na2CO3 12%(w),海参加工液72%(w),37℃下萃取,蛋白和多糖的回收率分别为96.9%和90.6%. 将该体系从30 g规模逐级放大到3 kg,多糖回收率降低1%,蛋白回收率降低0.7%,该体系可同时降低重金属含量.     

利用双水相乙醇-磷酸氢二钾体系萃取甘草有效成分的研究

研究了基于与水互溶的普通有机溶剂的双水相萃取体系 ,并考察不同种类盐分相能力的差异情况 ,根据分相后有机溶剂相的体积变化 ,选择乙醇 (EtOH) 磷酸氢二钾 (K2 HPO4)体系萃取甘草有效成分。确定萃取的最佳条件是 :当双水相体系的总量为 10mL ,V(EtOH)∶V(H2 O)=3∶2 ,磷酸盐的质量为 1 5 g ,在上述条件下 ,EtOH K2 HPO4体系的两相分配完全 ,分配系数(K)最大为 12 80 ,收率 (Y)高达 98 3%。     

EXTRACTION OF ACETOIN FROM FERMENTATION BROTH USING AN ACETONE/PHOSPHATE AQUEOUS TWO-PHASE SYSTEM

An aqueous two-phase system (ATPS) consisting of acetone and phosphate was used to extract acetoin from fermentation broth. The influence of phase composition on partition of acetoin was investigated. When the filtered fermentation broth was used, relatively high partition coefficient (22.3) and recovery coefficient (96.4%) of acetoin were obtained by a system composed of 30% (w/w) acetone and 35% (w/w) dipotassium hydrogen phosphate. Then the system was applied to extract unfiltered fermentation broth directly, and the recovery coefficient of acetoin was 94.3%. Simultaneously, the byproduct 2,3-butanediol could also be extracted with the recovery coefficient of 93.5%. In addition, the removal of residual sucrose, cells, proteins, and prodigiosin from the fermentation broth was studied, and the removal ratios of these impurities were all above 85%. Ultimately, the recovery of phosphate in the bottom phase was explored, and the recovery coefficient could reach 93.7% through pH adjustment and dilution crystallization. The recovered phosphate also showed good ATPS extraction ability. This method provides a new possible way for the separation of acetoin from fermentation broth.     

Partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid in PEG/ammonium sulfate aqueous two‐phase systems

In order to develop an aqueous two‐phase system (ATPS) for cephalexin synthesis with extractive bioconversion, the partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid (7‐ADCA) in poly(ethylene glycol) (PEG)/salt ATPS were examined. Parameters such as PEG size, salt type and tie line length were investigated to find a primary extraction system. In PEG400/ammonium sulfate and PEG400/magnesium sulfate systems, the partition coefficient of cephalexin (K_C) was larger than 1 while that of 7‐ADCA (K_A) deviated about 1.5. Addition of neutral salts, surfactants and water‐miscible solvents were also investigated in the primary ATPS in order to improve the separation efficiency. K_C greatly increased when neutral salts and surfactants were added to the PEG400/ammonium sulfate primary systems whereas K_A was only slightly higher than that of the additive‐free ATPS. In an improved ATPS for extractive bioconversion, consisting of PEG400 (20% w/w), ammonium sulfate (17.5% w/w), methanol (5% w/w) and NaCl (3% w/w), a K_C value of up to 15.2 was achieved; K_A was 1.8; K_P (partition coefficient of phenylglycine methyl ester) was 1.2 and the recovery yield of cephalexin was 94.2%. The results obtained from the extractive bioconversion of cephalexin in the improved ATPS showed that it is feasible to perform such an enzymatic process in an ATPS and the system offers the potential as a model for enzymatic synthesis of some water soluble products. © 2001 Society of Chemical Industry     

盐析萃取菊芋发酵液中的2,3-丁二醇(英文)

The removal of solid impurities and separation of target products from a fermentation broth is becoming more tedious with the utilization of lignocelluloses as source of substrate.2,3-Butanediol,an important chemical used widely is also a main product of sugar-based fermentation carried out by Klebsiella pneumoniae.In this study,we investigated the use of salting-out extraction(SOE) that employed a K2HPO4/ethanol system consisting of 21% ethanol and 17% K2HPO4(mass fraction) to separate 2,3-butanediol from the viscous Jerusalem artichoke-based fermentation broth.After SOE,about 98% of solid matters was removed,and the viscosity decreased from 72.5 mPa s in the original fermentation broth to 4.4 mPa s in the top phase.The partition coefficient and yield of 2,3-butanediol reached 13.4 and 99%,respectively,and 89% of soluble proteins was removed from the broth.The results showed that SOE is an efficient way for isolating 2,3-BD from a highly viscous fermentation broth by removing much of the solid matters within the broth.     

1,2,4-丁三醇的双水相萃取

对低分子有机溶剂/无机盐双水相体系萃取分离发酵液中1,2,4-丁三醇（1,2,4-butanetriol，BT）进行了深入研究。通过对不同双水相体系的筛选，最终选定无水乙醇/K₂HPO₄双水相体系来萃取分离BT。使用浊点法对以BT为溶剂的无水乙醇/K₂HPO₄双水相体系进行相图的绘制，发现在K₂HPO₄质量分数为19.83%~46.87%范围内均能成相。通过单因素实验，考察双水相体系中无水乙醇/K₂HPO₄质量分数、pH对BT在两相之间分配系数和萃取效率的影响，得到最佳萃取条件为：系统总量10g、pH 9.5，无水乙醇/K₂HPO₄的质量分数为28%/28%，分配系数和萃取效率分别可以达到18.35和95.87%。在最佳萃取条件下，进一步探究了放大实验对体系萃取效率的影响，发现其对分配系数和萃取效率影响较小，体系稳定性高，为工业提取发酵液中BT提供新思路。     

利用肺炎克雷伯氏菌以葡萄糖和磷酸铵盐为底物生产2,3-丁二醇

1 INTRODUCTION Interest in microbial production of 2,3-butanediol has been increasing recently due to the extensive indus-trial application of this product. This colorless and odorless liquid with a high boiling point and a low freezing point is a potential valuable fuel additive. Its heating value is 27.198kJ·g-1, which is quite near the value of ethanol (29.055kJ·g-1). Besides, condensation of diol to methyl ethyl ketone (MEK) coupled with subsequent hydrogenation yields octane isom…     

Determination of Teicoplanin A2's Partition Coefficient in Different Liquid-Liquid Extraction Systems

Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partition coefficients and extraction ratio of teicoplanin in three different solvent systems were studied: conventional extraction, reactive extraction and reverse micelle extraction. With conventional solvent extraction, n-butanol demonstrated high partition coefficient for teicoplanin, but low extraction ratio because of its high solubility in water. Reactive extraction of teicoplanin showed the highest partition coefficient with almost 100% recovery in organic phase when tri-n-octylmethyl ammonium chloride (TOMAC) was used as extractant and pH value was above 5.0. A reverse micelle system, consisted of isooctane 10mmol-L-1 TOMAC 1% n-octanol, also offered high separation factor for teicoplanin. The results are beneficial for the design of teicoplanin separation and purification process.     

Investigation of Three-liquid-phase Extraction Systems for Simultaneous Separation of Emodin and Rhein

Several three-liquid-phase extraction systems comprised of organic extractant,polymer and salt aqueous solution were applied to isolate and purify simulated herbal extract containing emodin and rhein.Some influential factors on the partitioning behaviors were studied.The results revealed that extractant type and solution pH value were crucial factors for improving the separation performance.The optimal separation results were obtained at pH 8.00 with methyl isobutyl ketone as the extractant,10%（ω） polyethylene glycol with the molecular weight 4000 Da,and 10%（ω） ammonium sulphate.Under the optimized conditions,95%emodin and 97%rhein were simultaneously extracted into the organic phase and polymer-rich phase from simulated herbal solution with the initial concentration of 100×l0^-6（ω）,respectively,and their separation factor of over 10000 was achieved.By adjusting pH value,back extraction rate of both emodin and rhein could be up to about 99%.With the assistance of molecular simulation program XLOGP3 and molecular orbital package,the possible mechanism of extraction was analyzed,and hydrophobic interaction and hydrogen-bonding interaction might be the major driving forces affecting the partitioning behaviors of emodin and rhein.     

葡萄糖和木糖双底物生物合成2,3-丁二醇的条件优化

针对利用葡萄糖和木糖合成2,3-丁二醇的Klebsiella pneumoniae XJ-Li菌,优化培养基组成与发酵条件,围绕五、六碳糖共代谢的特点,探讨简单可行的代谢调控方法. 结果表明,60 g/L葡萄糖和40 g/L木糖为碳源,5.75 g/L NH4H2PO4为氮源,pH值维持在5.5,培养温度38℃, 2,3-丁二醇浓度可达19.24 g/L. 确定了pH值调控和外源添加维生素C的调控方式,通过调节发酵过程中pH值于5.5左右,使2,3-丁二醇的产量提高了16.4%;添加60 mg/L维生素C调节培养基的氧化还原状态,可使2,3-丁二醇的产量提高44.3%,批式发酵48 h, 2,3-丁二醇终浓度可达33.47 g/L.