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张继岭 《中国生物工程杂志》1996,16(2):50-55
本文论述了生物大分子活性物质对超滤装置的基本要求。介绍了我国生物工程一些领域使用超滤技术的概况,阐述了HFS系列超滤装置的设计功能及该系列装置在我国应用情况。 相似文献
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本文论述了生物大分子活性物质对超滤装置的基本要求。介绍我国生物工程一些领域使用超滤技术的概况,阐述了HFS系列超滤装置的设计功能及该系列装置在我国应用情况。 相似文献
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自从 1988年首次发现肠球菌 (GRE)对糖肽类抗生素耐药以来 ,肠球菌己成为医院感染的重要病原菌 ,给临床治疗造成了极大的困难。为了解我院肠球菌的流行及耐药现状 ,我们对我院 1999年 5月至 2 0 0 2年 4月分离到的 51株肠球菌种类分布及耐药性作了回顾性分析 ,现将结果报告如下。1 材料与方法1.1 标本来源 从 1999年 5月至 2 0 0 2年 4月我院所有血、体液 (胸水、腹水、脑脊液等 )标本和部分痰、分必物等标本分离到的肠球菌共计 51株。1.2 仪器及试剂 mini VITAL全自动荧光血培养仪及专用需氧和厌氧血培养瓶 ,VITEK-3 2全自动细… 相似文献
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随着MRSA的越发,万古霉素在临床上的使用越来越频繁,成为治疗MRSA的最后一道防线;然而,对万古霉素敏感性下降的金黄色葡萄球菌的出现,临床上抗感染治疗面临极大困难,引起了医学界普遍的关注。本文对万古霉素敏感性下降的金黄色葡萄球菌的发展,耐药状况,作用机制,相关治疗和热门争议话题等方面的研究进展作一综述。 相似文献
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目前认为万古霉素中度耐药的金黄色葡萄球菌菌株一般从苯唑西林耐药的金黄色葡萄球菌转变而来。万古霉素中度耐药的金黄色葡萄球菌感染患者往往长期使用万古霉素或有慢性疾病。目前还没有系统检测万古霉素中度耐药的金黄色葡萄球菌的试验。如果用万古霉素治疗苯唑西林耐药的金黄色葡萄球菌感染失败,临床医生应警觉是否为万古霉素中度耐药的金黄色葡萄球菌感染。 相似文献
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生物分离中应用超滤的若干问题 总被引:5,自引:0,他引:5
本文对超滤技术应用中普遍存在着的诸多重要因素进行了讨论。有些内容在一般教材和方面中较少详细论述。本文从应用者角度分析了产率、吸附、消毒和保存、温控、活性问题、压力和秀过速率以及技术联用应该注意的问题,并将共与膜质量参数、膜配置选择和操作模式相关联。对活性生物样品的处理,文中给予了较多的讨论,并希望结合超滤技术自身特点,在选择和配置一节中,对系统的各组成部分进行部分进行配置优化。应用中,安全性操作也 相似文献
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With the goal of recovering heterologous immunoglobulin (IgG), which comprises 10-15% of the total proteins, from transgenic goat milk at 80% yield and 80% purity, we have developed and tested a two-step membrane isolation and purification process. In the first step, reported earlier by Baruah and Belfort, microfiltration was used to fractionate the milk proteins and recover > 90% of the original IgG at a purity of about 15-20% in the permeate stream. Here, we focus on ultrafiltration (UF) to increase the purity of the target protein to 80%, while maintaining a relatively high IgG yield (80%). Tangential flow UF experiments in diafiltration mode were conducted with 100 kDa cellulosic membranes to evaluate the optimal pH, ionic strength, and uniform transmembrane pressure (TMP). The TMP was kept uniform by permeate circulation in co-flow mode. The traditional approach of conducting the UF process close to the pI of the predominant whey proteins (15-40 kDa, pI 5.2), to transmit these proteins while retaining heterologous IgG (155 kDa), could not be applied here because of precipitation of residual casein at pH values lower than 8.5. Instead, the packing characteristics of the cake layer on the membrane wall, as elucidated in the Aggregate Transport Model presented by Baruah et al. was utilized to achieve a selectivity of > 15, which was sufficient to meet the stated goals of purity and yield for this difficult separation. This combined process is expected to reduce the load on subsequent purification and polishing steps for eventual therapeutic use. 相似文献
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主要研究了从蛹虫草发酵液中提取虫草素的工艺,确定了大孔吸附树脂AB-8及十八烷基键合硅胶反相层析柱对蛹虫草发酵液中虫草素的分离条件;吸附最佳工艺条件为上样液p H6,上样浓度0.4mg/m L,上样量5BV,吸附流速1.0BV/h;解吸最佳工艺条件包括解吸液20%乙醇,解吸体积15BV,解吸流速4BV/h。得到的解吸液进一步以十八烷基键合硅胶分离,条件为上样液p H6,梯度洗脱,流动相为p H6的水和p H6的乙醇。洗脱液通过结晶和重结晶得到精制虫草素。三步得到的虫草素纯度分别达到40%、90%和99%以上。 相似文献
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中试规模纯化重组人核苷二磷酸激酶A(rhNDPK-A)。菌体高压匀浆,然后微滤去除菌体碎片,超滤浓缩,所得样品上样DEAE-sepharose Fast Flow,收集目的峰,上样Cibacron Blue 3GA Sepharose CL-4B,含ATP的缓冲液洗脱目的蛋白,超滤精制。结果表明,1500g菌体经过2次匀浆后,所得匀浆液中含NDPK47.6g,经过微滤超滤处理后,可回收目的蛋白27.3g。再经过两步柱层析及超滤精制后,最终可得纯度为96.3%的目的蛋白17.2g,总回收率为36.2%,每100g湿菌体的蛋白产率为1.15g。比较每个步骤的回收率,发现精制>亲和层析>离子交换层析>样品前处理过程。与前期报道发酵工艺联用,rhNDPK-A的纯化产量达到510mg/L。工艺简便、得率高的rhNDPK-A纯化工艺的建立为NDPK的应用开发提供了物质基础;另外,本文结果也提示,对于非分泌型重组蛋白来说,影响目的蛋白回收的最主要因素可能不是柱层析,而是样品前处理过程。 相似文献
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Two endo-1,4-β-d-xylanases (1,4-β-d-xylan xylanohydrolase, EC 3.2.1.8) from Trichoderma harzianum E58 have been purified by ultrafiltration and chromatography on carboxymethyl-Sepharose, phenyl-Sepharose and Sephadex G-75. The d-xylanases were shown to be homogeneous by the criteria of dodecyl sulphate polyacrylamide gel electrophoresis and isoelectric focusing. The molecular weights were estimated to be 20 000 and 29 000, with pl values of 9.4 and 9.5, respectively. Typically, 456 mg of the 20 000 dalton and 1.9 mg of the 29 000 dalton d-xylanases were purified from 4.2 litre of culture filtrate with specific activities of 370 and 75 U mg?1, respectively. Optimum d-xylanase activities were obtained when the enzymes were incubated at pH 5, 50°C, for the 20 000 dalton protein and pH 5, 60°C for the 29 000 dalton protein. 相似文献
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The present study was to investigate the purification of a fermentation broth by an electromicrofiltration membrane. Microfiltration
runs with a crude and a centrifuged broth, with solution of particles recovered from centrifugation and with permeates from
microfiltration experiments were thus compared.Microfiltration performances were governed by colloids and small particles
that induced sharp initial flux declines. For these results, the evolution of the overall membrane resistance was increased
by 80% in comparison with the electromicrofiltration membrane. The main focus of this study was set on the enhancement of
the filtrate flux by an electric field. This pressure electrofiltration leads to a drastic improvement of the filtration by
100% and the filtration time was thereby reduced. Pressure electrofiltration serves as an interesting alternative to the cross-flow
filtration and it effectively separates advantageous constituents such as amino acids and biopolymers from a fermentation
broth. They were equally maintained during the microelectrofiltration, although they were significantly reduced by 45% by
the microfiltration without the application of an electric field. Accordingly, since the electrofiltration membrane was provided
more permeability, this study experimentally demonstrates that the permeability inside a membrane can be controlled using
an electric field. 相似文献
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Schiraldi C Alfano A Cimini D Rosa MD Panariello A Restaino OF Rosa MD 《Biotechnology progress》2012,28(4):1012-1018
Recently, the possibility of producing fructosylated chondroitin from the capsular polysaccharide of Escherichia coli O5:K4:H4, in fed‐batch and microfiltration experiments was assessed on a 2 L bioreactor. In this work, a first scale‐up step was set on a 22 L membrane reactor with modified baffles to insert ad hoc designed microfiltration modules permanently inside the bioreactor vessel. Moreover, the downstream polysaccharide purification process, recently established on the A¨?KTA cross‐flow instrument, was translated to a UNIFLUX‐10, a tangential flow filtration system suitable for prepilot scale. In particular, the microfiltered permeates obtained throughout the fermentation, and the supernatant recovered from the centrifuged broth at the end of the process, were treated as two separate samples in the following ultrafiltration procedure, and the differences in the two streams and how these affected the ultrafiltration/diafiltration process performance were analysed. The total amount of K4 capsular polysaccharide was about 85% in the broth and 15% in the microfiltered permeates. However, the downstream treatment was more efficient when applied to the latter. The major contaminant, the lipopolysaccharide, could easily be separated by a mild hydrolysis that also results in the elimination of the unwanted fructosyl residue, which is linked to the C‐3 of glucuronic acid residues. The tangential ultrafiltration/diafiltration protocols developed in a previous work were effectively scaled‐up, and therefore in this research proof of principle was established for the biotechnological production of chondroitin from the wild‐type strain E. coli O5:K4:H4. The complete downstream procedure yielded about 80% chondroitin with 90% purity. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1012–1018, 2012 相似文献
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HPLC-ELSD法测定发酵液中L-精氨酸含量 总被引:3,自引:0,他引:3
建立了一种快速、准确的高效液相色谱-蒸发光散射检测法(HPLC-ELSD)测定发酵液中L-精氨酸含量。采用Prevail C18色谱柱(C18 5μm,250×4.6 mm,Alltech),以5 mmol.L-1七氟丁酸(三氟乙酸调pH至1.0)和乙腈为流动相,采用梯度洗脱,总流速为1.0 mL/min。ELSD参数:漂移管温度为117.0℃,载气流速为3.2 L/min。L-精氨酸等氨基酸的回收率为96%~104%。能够快速、精确测定发酵样品中目的产物L-精氨酸与其它氨基酸含量。 相似文献