一株产溶栓酶枯草杆菌的微胶囊固定化培养

引　言临床上常采用一些具有激活血液中纤维蛋白酶原的激活剂 ,使纤溶酶原转变为纤维蛋白的溶解酶 ,以使纤维蛋白溶解 ,从而达到预防和治疗心脑血管疾病的目的 .目前应用的溶栓药物主要有链激酶、尿激酶 (ＵＫ) [1] 等 .本文中的溶栓酶具有直接溶栓和纤溶酶原激活双重功能 ,是一种很有发展潜力的新型溶血栓药物 .ＮａＣＳ -ＰＤＭＤＡＡＣ(硫酸纤维素钠 -聚二甲基二烯丙基氯化铵 )生物微胶囊具有制备方法简单、膜物理化学性质稳定及机械强度好等优点 ,受到国际上的重视与研究[2～ 6] .本文拟用ＮａＣＳ -ＰＤＭＤＡＡＣ微胶囊进行枯草杆菌产…     

聚氨酯泡沫固定化重组枯草杆菌三段培养生产青霉素酰化酶

引　言青霉素G酰化酶 (penicillinGacylase ,EC3 5 1 11,PGA)是 β 内酰胺类抗生素工业中的关键酶之一 .目前主要采用大肠杆菌和巨大芽孢杆菌进行工业化生产 ,但由于产酶水平较低、变温发酵和需要苯乙酸诱导等缺点 ,国内外研究者尝试采用各种基因重组技术 ,以期大幅度提高产酶     

β-葡萄糖苷酶ACA微胶囊固定化实验研究

对壳聚糖为壁材的共价交联固定、海藻酸钠为壁材的包埋固定及壳聚糖和海藻酸钠共用的新型复合载体(ACA)固定的β-葡萄精苷酶进行了对比研究,得出ACA微胶囊固定化的酶具有较好的催化活性、重复使用和低温贮藏性能.醋酸和戊二醛及CaCl2的浓度、壳聚糖和海藻酸钠用量、引发和交联时间对ACA微胶囊固定酶的形态和性能影响较大,葡萄糖转化率随醋酸与戊二醛和CaCl2浓度的增加、壳聚糖和海藻酸钠用量的增大,交联和引发时间的延长呈先增大后减小的变化趋势,并于不同特定值达到最大.     

PVA混合载体固定化枯草杆菌的研究

用ＰＶＡ作为基础载体，固定化枯草杆菌Ｎ＿２－９３，在机械搅拌罐内发酵，生产α－淀粉酶，同时添加部分海藻酸钠以改进载体扩散性能。考察了载体浓度及配比对固定化细胞载体性能、机械强度及产酶特性的影响。结果表明，添加少量海藻酸钠的ＰＶＡ载体具有较好的传质效果及机械强度。在５Ｌ搅拌发酵罐中连续发酵，最佳稀释率可达１．０ｈ（－１），连续发酵酶活保持在２７０μ／ｍ以上，载体无溶胀，破碎现象。     

纤溶酶溶栓新药的研究进展

纤维蛋白溶酶(纤溶酶)与传统的纤溶酶原激活剂相比,具有更为理想的溶栓效果和安全性。本文对纤溶酶、微纤溶酶及小纤溶酶作为溶栓新药的研究进展作一综述。     

酶的固定化技术

酶是一种高活性的生物催化剂,虽然其在酶生物燃料电池和传感器等方面的应用十分广泛,但酶在工业上的广泛应用一直受到很多限制,因为酶在水溶液中一般很不稳定.酶的固定化技术与合理设计、酶生物传感器的结构仍然是酶生物燃料电池和传感器领域今后研究的重要方向.如果通过酶的固定化技术的改进能使酶在使用过程中提高其稳定性,保持催化活性将使酶生物传感器得到更大的发展.     

SA/NaCS-CaCl2/PMCG微胶囊固定化枯草杆菌HL-1发酵生产纳豆激酶

制备了海藻酸钠/纤维素硫酸钠-CaCl₂/聚亚基二胍氯化氢微胶囊（SA/NaCS-CaCl₂/PMCG微胶囊）,并以该微胶囊固定化培养枯草杆菌HL-1用于发酵制备纳豆激酶,考察了PMCG对枯草杆菌生长的影响,比较了微囊化培养与游离培养过程中的菌体生长、耗糖速率以及纳豆激酶产物分泌能力.最后经过连续6批培养,酶活可达到2465 IU•ml^-1,是游离培养过程的3倍.     

漆酶的固定化研究

<正> 漆酶(EC.1.10.3.2)最先由Yoshida发现,经过近百年来的研究,特别是现代化科学仪器的大量分析测试,人们对它的认识在不断深化。关于漆酶的性质、催化特点和结构等已有文献综述。本文单就近年来固定化漆酶的研究概况作个介绍,以促进我国漆酶的开发利用。酶是生物体内的催化剂。如果没有酶,生物界将永远是一片死寂。但酶都是水溶性     

Burkholderic cepecia 1003产海因酶固定化条件

海因酶是利用海因酶法制备手性氨基酸的关键酶。采用Eupergit C、Eupergit C250 L及其氨基化后的载体作为固定化介质,对酶液pH值、蛋白浓度、固定化时间以及EDC用量等参数对海因酶固定化过程的影响进行研究,并在实验范围内,得到了上述参数的最优值。研究表明,环氧基载体的最适固定化条件为:酶液pH值为7.0,酶液蛋白质量浓度为0.4 mg/mL,固定化时间为20 h;氨基载体最适固定化条件为:酶液pH值为8.0,酶液蛋白质量浓度为0.4 mg/mL,固定化时间为10 h,EDC用量:Eupergit C(NH2)为70μL,Eupergit C250 L(NH2)为120μL。其中以Eupergit C250 L为固定化载体,海因酶的活性回收率可高达87%,且固定化酶的稳定性也较好,酶活半衰期长达2 500 h左右,具有较好的稳定性。     

枯草杆菌溶栓酶的恒溶氧发酵研究

本文以枯草杆菌（Ｂａｃｉｌｌｕｓ　ｓｕｂｔｉｌｉｓ）ＨＬ－９８６为试验菌株,对其恒溶氧发酵生产溶栓酶的的过程进行了研究,并与恒通气速率发酵作了比较。结果表明：与恒通气速率发酵相比,恒溶氧发酵可使溶栓酶生产能力提高３８．８％,在２２ｈ时溶栓酶活力可达 ９３０ＩＵ／ｍｌ,最佳条件是在发酵初期控制恒溶氧１５％。     

动态膜分离式固定化酶反应过程分析

测定了实验系统下固定化酶的本征动力常数,从动力学角度分析研究了所开发研制的动态膜分离式固定化酶反应器（DMIR）的反应过程,给出了无外扩散限制条件下的DMIR反应器的数学模型,并验证了实验方法的可靠性。     

涂料专用聚酯的连续制备新工艺

本文论述了固体多元醇与固体多元酸酐在反应挤出器中进行熔融加成反应连续地制备涂料专用聚酯的新工艺。     

SOME CONSIDERATIONS IN THE PRODUCTION OF FUSED MULLITE FOR REFRACTORIES *

The principles of the process of fusing ceramic materials for abrasives and refractories are now rather generally known. The benefits to be derived from the additions of fused materials to a refractory are likely to be (1) an increase of chemical resistance owing to the greater density and lower permeability, (2) an increase of load-bearing value of the product, and (3) a control of the kind and number of crystalline materials present in the grain as well as the proportion of glass contained. The term “flux” is not necessarily correctly used in connection with such fused materials, because it often applies only to a constituent which changes the proportions of the crystalline phases and does not affect the refractoriness or glass content.     

THE EFFECT OF SUBSTRATE MASS TRANSFER LIMITATIONS IN AN IMMOBILIZED ENZYME MEMBRANE REACTOR

An unstirred ultrafiltration cell can be quite easily converted into an immobilized enzyme reactor. Indeed, if suitable amounts ofproteic solutions are fed and if the protein molecular weight exceeds the membrane cut off, gel precipitation occurs onto the active surface of the membrane because of concentration polarization phenomena. Two different gel formation procedures have been followed. Indeed, two different proteic solution have been injected, namely

1.a mixture of an inert protein and the enzyme

2.co-polymer obtained by co-cross-linking the enzyme and the inert protein.

Substrate mass transfer limitations which occur in the gel immobilized enzyme reactor have been considered. The relevance of mass transfer resistances upstream from the immobilized gel layer has been discussed together with the intrinsic enzyme kinetics.

A heterogeneous gel model has been proposed which adequately describes the experimental results. Effectiveness factor correlations of fairly general applicability have been also presented.     

PREPARATION AND PERMEABILITY CONTROL OF ELECTRO-SENSITIVE MICROCAPSULES WITH IMMOBILIZED FERROELECTRIC LIQUID CRYSTALLINE SEGMENTS

Nylon-polystyrene microcapsules with immobilized ferroelectric liquid crystalline segments were prepared, and the permeability control of the encapsulated core material was investigated under an external electric field. A ferroelectric liquid crystal monomer possessing both mesogenicity and chirality effectively responded to an external electrical field. Permeation of the material (oxprenolol) contained in the inner aqueous core of the microcapsules was enhanced under a feeble electric field (2 V). Furthermore, it was found that the permeability of the microcapsules without the ferroelectric liquid crystal group did not depend on the external electrical field. In order to clarify the controlled release mechanism of the core material, the transmittance was quantitatively evaluated under an external electric field using a handmade polarized light transmittance apparatus.     

EFFECT OF SLOW INTRAPARTICLE DIFFUSION ON pH-STABILITY PROFILES OF IMMOBILIZED ENZYME

Stabilities of immobilized enzymes at varying pH under different levels of intraparticle diffusion limitation have been analyzed theoretically and numerically. Unlike pH-activity profiles, which are broadened at high levels of diffusion limitation, pH-stability profiles are narrowest at intermediate levels of limitation. When diffusion limitation is cither absent or very severe, pH-stability profiles are identical in shape, those under severe limitation having half-lives exactly double those free of limitation at all pHs.