高碳铬铁制备氢氧化铬的研究

以高碳铬铁合金粉为原料,经过硫酸高温搅拌浸出,通过草酸除铁法除铁后得到含杂质量低的硫酸铬溶液,然后用碳酸氢铵调节硫酸铬溶液pH得到氢氧化铬沉淀.研究了溶液中铬离子浓度、反应温度、pH以及各种添加剂对铬(Ⅲ)的沉淀回收率及氢氧化铬沉淀过滤性的影响.通过实验得到溶液中铬(Ⅲ)回收的最佳条件:反应温度为85 ℃、溶液中铬(Ⅲ)质量浓度为10 g/L、pH=6.5、搅拌强度为200 r/min.在此条件下铬(Ⅲ)的回收率高达99%,并且氢氧化铬沉淀具有较好的过滤性, 滤液中铬质量浓度达0.001 5 g/L,完全可达到国家排放标准,具有一定的工业实用价值.     

双水相体系萃取木瓜蛋白酶的研究

采用聚乙二醇(PEG)/(NH4)2SO4双水相体系对木瓜蛋白酶进行萃取分离,研究了PEG相对分子量、PEG质量分数、(NH4)2SO4质量分数和pH值对木瓜蛋白酶分配系数及酶活力回收率的影响.结果表明,最佳萃取条件为:PEG4000质量分数6%、(NH4)2SO4质量分数18%、pH值6.0,在此条件下,木瓜蛋白酶的...     

双水相体系萃取精氨酸脱亚胺酶

报道了利用聚乙二醇/硫酸铵双水相体系从自溶NJ402菌粗提酶液中分离纯化精氨酸脱亚氨酶(ADI)的研究结果,为精氨酸脱亚氨酶的分离纯化提供了一种方法。在双水相体系中采用聚乙二醇(PEG)与(NH4)2SO4为组成成分,考察了聚乙二醇(PEG)平均相对分子质量、PEG质量分数、(NH4)2SO4质量分数、pH及NaCl质量分数对精氨酸脱亚氨酶分离纯化效果的影响。最佳双水相体系萃取条件为:聚乙二醇(PEG)平均相对分子质量为1 000,w(PEG1000)=15%,w[(NH4)2SO4]=20%,pH=6.5,室温下从自溶NJ402菌粗提酶液中分离纯化精氨酸脱亚氨酶,纯化倍数达到2.35倍,萃取率达91.1%。     

乙肝表面抗原在微球表面的吸附行为、活性和结构变化

采用快速膜乳化技术结合溶剂挥发法制备了尺寸均一的聚乳酸(PLA)微球,平均粒径为800 nm左右,并采用PLA微球对乙肝表面抗原(HBsAg)进行了吸附研究,考察了pH值、盐浓度、微球用量、HBsAg浓度及吸附温度对HBsAg吸附率、活性和结构的影响. 结果表明,在pH 6.0的磷酸缓冲溶液中,NaCl浓度为20 g/L、微球用量为20 mg/mL、HBsAg浓度为10 mg/mL、吸附温度为37℃的条件下,HBsAg吸附率可达60%左右. 4℃下,pH值为8.0及NaCl浓度为1 g/L、微球用量为2 mg/mL及HBsAg浓度为300 mg/mL时,HBsAg活性保留可达98%以上.     

双水相萃取直接从枯草芽孢杆菌发酵液中提取β-甘露聚糖酶

研究了聚乙二醇(PEG)平均相对分子质量、PEG浓度、(NH4)2SO4浓度、NaCl浓度对β-甘露聚糖酶和总蛋白分配系数、相体积比和萃取率的影响。实验表明PEG100020%(m/m)和(NH4)2SO415%(m/m),NaCl为2%(m/m)组成的双水相体系,室温下直接对含菌体的枯草芽孢杆菌发酵液抽提β-甘露聚糖酶,可纯化2.76倍,萃取率达98.79%。     

磷矿脱镁废液制备纳米级氢氧化镁的工艺研究

以磷矿除镁后的废液与氨水为原料,在撞击流反应器中,采用氨法二步沉淀,探索了回收镁元素的工艺过程,制取了高纯度的氢氧化镁粒子,以聚乙二醇(PEG)6000为分散剂,制备出分散性良好的纳米氢氧化镁粒子。探讨了有关因素对产品中氢氧化镁含量和氧化镁回收率的影响,确定了适宜的工艺条件:除镁废液中氧化镁质量浓度为0.008g/mL,第一次中和反应终点pH值为9.5,第二次中和反应终点pH值的范围为10.20~10.30,第二次中和反应时间为45min,分散剂PEG6000的用量为纳米氢氧化镁理论产量的3%,采用三次沉降方式洗涤产品。制备的纳米氢氧化镁粒子粒径大小在40nm左右,产品中氢氧化镁质量分数为99.27%,氧化镁回收率为83.07%。     

重组G145R HBsAg亲和纯化方法的建立及其应用

目的建立重组乙型肝炎病毒G145R变异HBsAg抗体亲和纯化方法。方法用抗-HBs单克隆抗体(D12- McAb)制备亲和层析胶,对2A8细胞(分泌G145R变异HBsAg)培养上清盐析物进行亲和纯化。采用SDS-PAGE、Western blot及ELISA,对纯化产物的纯度、特异性、含量和回收率进行鉴定,并与同法纯化的HBsAg阳性血清及r-wHBsAg提取物进行比较。结果D12-McAb对重组真核表达G145R变异HBsAg、HBsAg阳性血清及r-wHBsAS三者具有相似的亲和性,产物纯度分别为90.3%、95.2%和93.1%,回收率分别为43.3%、72.0%和66.4%。结论已成功地建立了重组G145R变异HBsAg抗体亲和纯化方法,为G145R变异以及其他HBV免疫逃逸变异感染的深入研究奠定了重要的技术基础。     

双水相分离提取胃蛋白酶和琼脂糖的初步研究

以聚乙二醇/硫酸钠双水相体系分离提取琼脂糖和胃蛋白酶.结果表明:琼脂糖的回收率高于90%,胃蛋白酶的回收率约为50%,两者最适宜的分离条件为:pH值为3,Na2SO4浓度为0.4 g·mL-1,PEG10000的浓度为0.002 mol·L-1.     

锌离子螯合亲和层析分离纯化谷胱甘肽的研究

以谷胱甘肽的酵母抽提液为原料,用自制的以壳聚糖小球为载体、Zn2 为配基的金属螯合亲和层析柱分离纯化谷胱甘肽(GSH).用含0.5 mol·L-1NH4Cl的pH值4.2、0.02 mol·L-1的磷酸盐缓冲溶液洗脱,然后经浓缩、冷冻干燥处理,即得到分离纯化的GSH.结果表明,上柱谷胱甘肽抽提液浓度为 132.30 mg·(100 mL)-1、上柱pH值为7.0时,谷胱甘肽回收率为68.61%;洗脱液中氯化铵浓度为0.5 mol·L-1、洗脱pH值为6.0时,谷胱甘肽洗脱回收率达到44.47%.     

高强度耐有机溶剂蛋白酶的纯化及性质

分离纯化了自行筛选的耐有机溶剂的地衣芽孢杆菌Bacillus licheniformis YP1所产的溶剂稳定性蛋白酶. 发酵液经硫酸铵沉淀、疏水层析及强阳离子交换层析纯化,得到电泳纯的蛋白酶;分子量约为28 kDa,纯化蛋白酶的比酶活达到1.18′105 U/mg,纯化倍数为37.2,酶活回收率为20.8%. 纯化的YP1蛋白酶对50%(j)的多种亲水或疏水有机溶剂具有很高的耐受性,其中50%(j)的DMF和DMSO能显著促进YP1蛋白酶活力. YP1蛋白酶为Zn2+蛋白酶,最适反应温度为55℃,最适反应pH为10.0,pH 8.0~13.0范围内具有高活力. 以酪蛋白为底物,YP1蛋白酶的米氏常数Km为0.048 g/L.     

Improved recovery of B‐phycoerythrin produced by the red microalga Porphyridium cruentum

A simplified process for the primary recovery and purification of B‐phycoerythrin (BPE) from Porphyridium cruentum exploiting aqueous two‐phase systems (ATPS) and isoelectric precipitation was developed in order to reduce the number of unit operations and benefit from increased purity and yield of the protein product. Evaluation of the partitioning behaviour of BPE in polyethylene glycol (PEG)/sulphate, PEG/dextran and PEG/phosphate ATPS was carried out to determine under what conditions the BPE and contaminants concentrated into opposite phases. An additional stage of isoelectric precipitation at pH 4.0 after cell disruption resulted in an increase in purity of the target protein from the BPE crude extract and enhanced the performance of the subsequent ATPS. PEG1000/phosphate ATPS proved to be suitable after isoelectric precipitation for the recovery of highly purified (defined as absorbance ratio A_{545 nm}/A_{280 nm} > 4.0) BPE with a potential commercial value as high as US$ 50/mg. An ATPS extraction stage comprising 29.5% (w/w) PEG1000, 9.0% (w/w) phosphate, a volume ratio (V_r) equal to 1.0, a system pH of 7.0 and loaded with 40% (w/w) of the BPE extract generated by precipitation allowed BPE recovery with a purity of 4.1±0.2 and an overall product yield of 72% (w/w). The purity of BPE from the crude extract increased 5.9‐fold after isoelectric precipitation and ATPS. The results reported herein demonstrate the benefits of the practical application of isoelectric precipitation together with ATPS for the recovery and purification of BPE produced by P. cruentum as a first step in the development of a commercial purification process. Copyright © 2006 Society of Chemical Industry     

Practical application of aqueous two‐phase systems for the development of a prototype process for c‐phycocyanin recovery from Spirulina maxima

A novel process for the recovery of c‐phycocyanin from Spirulina maxima exploiting aqueous two‐phase systems (ATPS), ultrafiltration and precipitation was developed in order to reduce the number of unit operations and benefit from an increased yield of the protein product. The evaluation of system parameters such as PEG molecular mass, concentration of PEG as well as salt, system pH and volume ratio was carried out to determine under which conditions the c‐phycocyanin and contaminants concentrate to opposite phases. PEG1450–phosphate ATPS proved to be suitable for the recovery of c‐phycocyanin because the target protein concentrated in the top phase whilst the cell debris concentrated in the bottom phase. A two‐stage ATPS process with a phase volume ratio (V_r) equal to 0.3, PEG1450 7% (w/w), phosphate 20% (w/w) and system pH of 6.5 allowed c‐phycocyanin recovery with a purity of 2.4 (estimated as the relationship of the 620 nm to 280 nm absorbances). The use of ultrafiltration (with a 30 kDa membrane cut‐off) and precipitation (with ammonium sulfate) resulted in a recovery process that produced a protein purity of 3.8 ± 0.1 and an overall product yield of 29.5% (w/w). The results reported here demonstrated the practical implementation of ATPS for the design of a prototype recovery process as a first step for the commercial purification of c‐phycocyanin produced by Spirulina maxima. © 2001 Society of Chemical Industry     

基于疫苗颗粒完整性的硅胶吸附/解吸附纯化重组乙肝表面抗原 工艺研究

针对重组汉逊酵母乙肝表面抗原(HBsAg)在传统纯化过程中稳定性差的问题，采用静态光散射、荧光光谱和动态光散射等分析手段，从颗粒完整性角度研究其在不同pH条件下的稳定性变化。以其为指导，采用硅胶吸附/解吸附纯化HBsAg，建立该过程中关键因素的响应面模型，并与疏水层析联用，进一步纯化HBsAg，分析纯化效果以及纯化后疫苗颗粒完整性。采用透射电镜观察纯化后疫苗形貌，用高效分子排阻色谱法(HPSEC)分析颗粒稳定性。结果表明在酸性溶液下，pH接近HBsAg等电点时，抗原颗粒间静电斥力减小，颗粒容易聚集；碱性条件下，抗原颗粒内部疏水基团暴露，造成颗粒解聚。建立响应面模型，以活性收率为响应值时，最佳纯化工艺为吸附pH=7.43，洗脱pH=10.48，洗脱温度55.4℃，此时活性收率最高为39.1%；以纯化倍数为响应值时，吸附pH=7.16，洗脱pH=10.52，洗脱温度55.1℃，此时纯化倍数最高为1.90。进一步对洗脱液进行疏水层析纯化，活性收率为49.73%，颗粒完整性为85.79%，透射电镜观察到抗原颗粒粒径为20~40 nm。与传统疏水层析方法相比，采用硅胶吸附/解吸附与疏水层析联用的纯化方法，疫苗活性收率提高31.99个百分点，颗粒完整性提高20.90个百分点，颗粒稳定性提高22.93个百分点。该研究为高效纯化重组HBsAg及提高疫苗纯化过程的颗粒完整程度等提供新思路。     

Acid Precipitation and Purification of Wheat Straw Lignin

ABSTRACT

The acid precipitation and purification of lignin from wheat straw soda pulping effluent were studied. Prior to lignin precipitation, the suspended solids and dissolved silica were removed from the effluent to avoid lignin contamination. Suspended solids and dissolved silica were removed by centrifugation and selective precipitation at pH 5, respectively. After these treatments, the pH of the effluent was reduced to an optimum pH value of 3.5 with sulfuric acid in order to precipitate lignin. About 80% of the total lignin was recovered. Effluent color and COD were simultaneously reduced by 82 and 71%, respectively. Lignin precipitate purification was carried out by washing with aqueous acidic solutions. Only the time and the agitation rate influenced the washing process. The purity of the lignin was very high when the time and rate of agitation during washing were low. Under optimum conditions, lignin with a purity of 99.5% can be obtained.     

Two-step purification strategy for enhanced recovery of recombinant hepatitis B surface antigen from Pichia pastoris

Univariate screening on factors affecting the purification performance of recombinant hepatitis B surface antigen (HBsAg) on ion exchange chromatography (IEC) and size exclusion chromatography (SEC) and the establishment of a two-step purification strategy were performed. Amongst four IEC adsorbents examined, the use of Q Sepharose XL IEC adsorbent under optimized conditions together with optimized SEC purification was able to efficiently purify HBsAg. An established purification strategy comprising the two techniques further demonstrated adaptability for scale-up operations with a final total purification factor (PF) of 94.82 ± 16.20, HBsAg purity of 95.48% and recovery yield of 78.07%.     

人精浆前列腺特异抗原的分离纯化及鉴定

用PEG－SephadexG－150两步法，从精浆中分离纯化前列腺特异抗原（PSA）。精浆标本先经PEG粗提，约去除80％的杂蛋白，再经柱层析，进一步提纯，提纯产物经SDS－PAGE及ELISA法证实为免疫纯。     

Separation of catalase from Amsonia orientalis with single step by aqueous two-phase partitioning system (ATPS)

Catalase from Amsonia orientalis was purified by ATPS, and its efficiency was compared against hydrophobic interaction chromatography. Activity recovery and purification fold of purified catalase by ATPS were examined under varying experimental conditions. The effects of various factors such as type of phase-forming salts, (PEG) mass, with their different concentrations, pH and temperature effects on partitioning were investigated. The highest activity recovery (156%) and purification fold (8.67) of catalase were obtained in the ATPS system containing 10% (g/g) PEG4000, 15% (g/g) Na₂SO₄ at pH 6.0 and room temperature. In hydrophobic interaction chromatography, the enzyme has been purified 12.54-fold with 57.5% recovery. The molecular weight of catalase was determined as 75 kDa by SDS-PAGE.     

The optimization of aqueous two‐phase extraction of lysozyme from crude hen egg white using response surface methodology

BACKGROUND: Aqueous two‐phase extraction is a versatile method for separating biological particles and macromolecules. In the present wok, the feasibility of using PEG 4000/potassium citrate aqueous two‐phase system (ATPS) for recovering and purifying lysozyme was investigated. Response surface methodology was used to determine an optimized ATPS for purification of lysozyme from crude hen egg white. RESULTS: Mathematical models concerning the purification of lysozyme from chicken egg white in polyethylene glycol 4000 (PEG 4000)/potassium citrate ATPS are established using response surface methodology. Screening experiments using fractional factorial designs show that the pH of the system significantly affects the recovery and purification of lysozyme. An optimized ATPS was proved to be at pH 5.5 and 30 °C and contained 18% (w/w) PEG, 16% (w/w) potassium citrate, 3.75% (w/w) potassium chloride (KCl). Under those conditions, the specific activity, purification factor and activity yield for lysozyme were 31100 U mg^?1, 21.11 and 103%, respectively. CONCLUSION: The PEG 4000/potassium citrate ATPS has the potential to be applied to establish bioprocesses for the primary recovery and partial purification of lysozyme. © 2012 Society of Chemical Industry     

重组类人胶原蛋白的分离纯化

目的 建立重组类人胶原蛋白分离及纯化工艺。方法 将工程菌株E.coli BL21 3.1在L1523型12.8L自控发酵罐中培养14h,发酵菌体经超声破碎、硫酸铵沉淀后,依次经DEAE-52和Sephadex G-100柱层析分离纯化。结果 发酵菌体干重达到71g/L,表达量为菌体蛋白量的29.4％,最终产物纯度达98％,回收率为80.5％,纯化倍数为3.4。结论 纯化的类人胶原蛋白达电泳纯,相对分子质量为90 000,N端序列为NH_2-H-D-P-V-V-L-Q-R-R-D-W-E-N-P-G,均与其因序列设计一致。     

表面活性剂对铝酸钠溶液中一水软铝石晶种分解的影响

研究了非离子及阴离子型表面活性剂(聚乙二醇、聚氧乙烯月桂醚和十二烷基苯磺酸钠)对铝酸钠溶液晶种分解制备一水软铝石的影响. 结果表明,十二烷基苯磺酸钠抑制溶液分解及晶体附聚,导致产物粒度细化;聚乙二醇可强化溶液分解,并促进晶体附聚;PEG1000添加量为1 g/L时获得最高分解率(32.39%),较空白提高8.37%;PEG1000添加量为5 g/L时附聚效果最好,产物的中位粒径为23.86 mm,较空白提高4.5%. XRD和热重分析结果表明,添加剂未改变产物晶型,产物均为一水软铝石和三水铝石.