平板式超滤膜在头孢菌素C生产中的应用

研究采用平板式超滤膜技术直接处理头孢菌素C的发酵液。实验结果表明,所用的超滤系统能够一步截留未经处理的头孢菌素C发酵液中的菌体蛋白、固体颗粒等杂质,去除蛋白能力是原工艺的10倍,过滤收率提高了6%。膜通量的衰减幅度较小,产品质量好。     

头孢菌素C的分离研究进展

通过分析头孢菌素C发酵液的特点,论述传统分离过程,同时介绍了新技术膜过滤的应用情况并与传统的工艺进行比较,指出未来膜技术在分离头孢菌素C中有广阔的应用前景.     

超滤膜分离技术在维生素B12生产中的应用

采用U1tra—flo超滤系统去除不经预处理的维生素B12发酵液中残留的菌丝体和蛋白质等杂质。用截留分了量为10万的UItra—flo膜过滤维生素B12发酵液,滤液质量高,平均膜通量可达到122．52L／m2·h^-1,膜通量衰减较慢,被污染的膜经清洗后与新膜没有明显的差异,说明Ultra-flo超滤系统处理能力强且可长时间稳定运行。该超滤系统现已在华北制药集团威可达公司成功应用。     

苏云金芽孢杆菌发酵液后处理工艺研究进展

介绍了苏云金芽孢杆菌发酵液后处理工艺研究进展.超滤法和沉淀法可以实现苏云金芽孢杆菌发酵液的浓缩,喷雾干燥法、碱溶-超滤法、膜过滤技术可以回收发酵液杀虫活性成分.     

头孢菌素C发酵液陶瓷膜过滤过程中的影响因素研究

为考察陶瓷膜在头孢菌素C发酵液膜过滤过程中的应用性能进行了实验研究,对影响较为显著的因素进行了分析讨论.给出了渗透通量在膜过滤过程中变化的完整曲线,分别分析说明了平均压差、顶洗、膜面流速等操作条件与渗透通量的关系.分析了不同温度下的CPC收率理论值与实测值的关系,并在此基础上考察了温度对渗透通量的影响.根据浓差极化理论,给出了渗透通量与浓缩比的关系式,并对其进行了实验验证.结果表明,较高的温度(15℃)有利于头孢菌素C发酵液膜过滤过程的进行,渗透通量与浓缩比a的对数呈线性关系,通量主要受到保留液主体固形物浓度CB的影响.此外,实验还发现,通过"清水置换-碱洗-清水置换-酸洗-清水置换"联合清洗方法,可使膜通量恢复到新膜通量的90%以上.     

超滤技术在生物酶分离中的研究进展

该文综述了超滤技术的原理、分离过程、发酵液的性质以及超滤膜和超滤条件对生物酶超滤性能的影响。并从发酵液的处理、超滤膜和超滤过程的优化三方面出发,对近期提高超滤性能取得的成果进行了总结和讨论。最后指出生物酶超滤技术的未来发展方向有以下几点:超滤数学模型的开发;提高酶的稳定性;超滤膜的改进和开发;超滤工艺的改进。     

超滤技术在赖氨酸生产中的应用

西文在要用超滤膜技术直接处理赖氨酸的发酵夜。实验结果表明，所用的超滤系统能够一步截留未经过任何处理的赖氨酸发酵液中的菌体蛋白，固体颗粒等杂质，赖氨酸有效成分的损失率可以控制在3％以内，即超滤的收率可达97％以上。滤渣的量约为原料体积的10％，而同等量的发酵液经过离子交换后，浓废水量约为该滤渣的20倍，所以大大减少了后续污物处理的压力。膜通量的衰减幅度较小，膜设备运行良好。     

超滤-醇沉法从发酵液中提取1,3-丙二醇

介绍了超滤-醇沉法从发酵液中提取1,3-丙二醇的工艺. 首先通过超滤,菌体、蛋白质与核酸的去除率分别为99%, 89.4%和69%,然后减压蒸馏浓缩发酵液,最后醇沉浓缩发酵液,使核酸、多糖、蛋白质等生物大分子沉淀析出,乙醇加入量与浓缩发酵液的最佳体积比为2:1. 粗产品中总蛋白和核酸与发酵液相比分别减少了97.4%和89.7%,溶液电导率下降了95.8%. 考察了浓缩发酵液的含水量、pH值对醇沉效果的影响及醇沉对发酵液中蛋白质、核酸、盐类的去除效果. 实验发现,浓缩液含水量越低,醇沉效果越好,浓缩发酵液含水量为1%时,杂质去除率达90%以上. 浓缩发酵液pH值的变化对醇沉杂质的影响较大,强碱和强酸条件下可沉淀出大量杂质.     

絮凝与膜超滤耦合预处理谷氨酰胺发酵液

采用絮凝与膜超滤相耦合的方法对谷氨酰胺发酵液进行预处理 ,详细讨论了壳聚糖做絮凝剂去除菌体和膜超滤去除蛋白和多糖等的效果及影响因素。实验表明 ,在壳聚糖质量浓度为80 0～ 10 0 0 g/m3 ,发酵液为 pH =4 0～ 6 0 ,温度 2 5℃左右 ,快速搅拌与慢速搅拌相结合的操作条件下 ,絮凝效果最佳 ,菌体去除率超过 95 %。采用截留相对分子质量为 6 0 0 0的中空纤维膜超滤絮凝后的谷氨酰胺发酵液 ,蛋白去除率 70 4 % ,总有机碳降低 5 7 3% ,大部分的蛋白和多糖被除掉。该预处理方法具有工业应用的前景     

超滤和纳滤膜分离提取纳他霉素

为提高纳他霉素(natamycin)生产提取得率,减少溶剂使用,本文采用超滤、纳滤操作对工业生产的纳他霉索发酵液进行处理。实验结果表明:操作压力、操作时间及料液流速对超滤过程有很大影响。通过超滤可将蛋白质等大分子杂质去除,然后再用纳滤膜对超滤渗透液进行浓缩纯化,对纳滤工艺的操作条件如进料压力、料液pH、浓缩倍数等进行了研究。采用超滤、纳滤技术提取纳他霉素,其收率可达62.74%。     

头孢菌素C发酵液可压缩性及膜分离的工艺研究

研究头C发酵液,确定头C发酵液具有一定的可压缩性,可压缩性指数在0．30～0．45之间。提出有效透膜压差的概念,认为膜通量与有效透膜压差成正比,对膜通量分析有积极作用。进一步探讨发酵液可压缩性对膜分离的影响,得出结论：可压缩性指数越小,有效透膜压差和透过通量越大,越有利于膜分离过程。     

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.     

Estimation of productivities in repeated fed batch cephalosporn fermentation

The theory of fed batch culture was tested on the cephalosporin C fermentation. In repeated fed batch culture a constant fraction of the culture volume is removed at fixed intervals. Since the productivity (output rate/unit volume) and specific rate of product formation may vary throughout the fed batch cycle, an “average productivity” and “average specific rate of product formation” which describe the overall behaviour of the system over several cycles are introduced. The test shows that the quasi-steady state of cephalosporin production predicted by fed batch theory can be maintained during at least 3.6 culture volume changes. The fed batch method of culture increased the productivity of the culture about 1.3 times with respect to that of simple batch culture whilst the cephalosporin C concentration was about the same in each type of culture.     

头孢菌素C发酵过程中蛋氨酸加量对菌丝形态及效价的影响

通过调整头孢菌素C发酵底物中蛋氨酸的浓度,对比不同时期的菌丝形态及效价,确定了蛋氨酸加量在8%时,头孢霉菌菌丝分化快速、均匀,并且在此浓度下发酵效价达到最高水平。     

Demineralization of glutamine fermentation broth by electrodialysis

The application of electrodialysis technology in demineralization of glutamine fermentation broth was studied. We used the one-dimension Nernst—planck equation to describe the process of demineralization of the glutamine fermentation broth system, did the theoretical calculation on the demineralization ratio and the loss rate of glutamine, and made a comparison with the experimental results. The results show: the one-dimension Nernst—Planck equation can describe the process of electrodialysis demineralization of the fermentation broth system, there is a little deviation between the result of the theoretical calculation and the experimental result, and the loss rate of glutamine in the experimental data is a little higher than that in the theoretical calculation. Moreover, we also investigated the change of the current efficiency of the simulation feed solution and fermentation broth in the electrodialysis along with the process of demineralization. The current efficiency decreases a little along with the process of demineralization, and the current efficiency in the fermentation broth is lower than that in the simulation feed solution.     

Processing of ethanol fermentation broths by Candida krusei to separate bioethanol by pervaporation using silicone rubber‐coated silicalite membranes

BACKGROUND: Pervaporation employing ethanol‐permselective silicalite membranes as an alternative to distillation is a promising approach for refining low‐concentration bioethanol solutions. However, to make the separation process practicable, it is extremely important to avoid the problems caused by the adsorption of succinate on the membrane during the separation process. In this work, the pervaporation of an ethanol fermentation broth without succinate was investigated, as well as the influence of several fermentation broth nutrient components. RESULTS: Candida krusei IA‐1 produces an extremely low level of succinate. The decrease in permeate ethanol concentration through a silicone rubber‐coated silicalite membrane during the separation of low‐succinate C. krusei IA‐1 fermentation broth was significantly improved when compared with that obtained using Saccharomyces cerevisiae broth. By treating the fermentation broth with activated carbon, bioethanol was concentrated as efficiently as with binary mixtures of ethanol/water. The total flux was improved upto 56% of that obtained from the separation of binary mixtures, compared with 43% before the addition of activated carbon. Nutrients such as peptone, yeast extract and corn steep liquor had a negative effect on pervaporation, but this response was distinct from that caused by succinate. CONCLUSION: For consistent separation of bioethanol from C. krusei IA‐1 fermentation broth by pervaporation, it is useful to treat the low nutrient broth with activated carbon. To further improve pervaporation performance, it will be necessary to suppress the accumulation of glycerol. Copyright © 2009 Society of Chemical Industry     

Span-20和Tween-80对发酵液中Nisin泡沫分离的影响

研究了微量非离子表面活性剂Tween-80和Span-20对发酵液中乳链菌肽(Nisin)泡沫分离的影响. 结果表明,发酵液泡沫分离时泡沫层轴向气泡直径、连续通气过程的泡沫层高度、泡沫层平均持气量等均因添加活性剂而明显变化. 不同体系气泡大小为,含0.2 g/L Span-20发酵液>含0.5 g/L Span-20发酵液>发酵液>含0.2 g/L Tween-80发酵液>含0.5 g/L Tween-80发酵液;Tween-80的加入破坏了气泡表面的网状结构,因而泡沫层持气量较高;连续通气时,2种表面活性剂都会引起泡沫层高度降低,但Tween-80会增加泡沫层的稳定性. 当Tween-80浓度达0.5 g/L时,Nisin的收率大幅度提高,原因是分离过程中Nisin失活率减少.     

膜分离技术分离纯化泰乐菌素的研究

简要介绍膜分离技术,采用超滤膜、纳滤膜对泰乐菌素发酵液进行脱色除蛋白试验。通过考查该体系膜通量、发酵液浓缩情况及滤液质量等,发现采用膜系统处理泰乐菌素发酵液在工艺、技术上是可行的,比传统过滤方式具备很多优越性。     

头孢菌素C发酵液膜过滤过程中收率的估算与控制

通过对头孢菌素C发酵液膜过滤过程的分析,引入了前浓缩比a、洗滤阶段稀释比b和后浓缩比c3个参数.针对采用连续洗滤操作模式和间歇洗滤操作模式的膜过滤过程,分别给出了总收率计算式和采用分段函数表示的过程收率计算式.通过计算比较了CFD和IFD操作模式下收率的变化情况,并进行了实验验证.结果表明,恰当选择的操作模式和参数值将有助于提高过程收率和缩短过滤时间,计算式能够为有效控制过滤过程收率提供理论依据.