生物反应器相关专利分析

生物反应器（bioreactor）是利用酶或生物体（如微生物）所具有的生物功能而进行生化反应的装置系统．如发酵罐．在各种生物加工过程中占据中心位置。从反应过程上看．根据培养对象的不同．生物反应器可以简单分为3类：微生物反应器和酶反应器、动植物细胞大规模培养生物反应器以及转基因动植物细胞生物反应器。     

生物反应器的概况及发展前景

生物反应器是人们为适应生物反应的特点以获得人们所需的生物化学产品而设计的反应设备。生物反应器又称生化反应器。凡反应中采用整体微生物细胞时,反应器则称发酵罐;凡采用酶催化剂时,则称为酶反应器。另还有适用于动植物细胞大量培养的装置,称为动植物细胞培养用反应器。     

动物细胞培养用生物反应器及相关技术

动物细胞大量培养是生产生物制品的重要途径,它用到的关键设备是生物反应器。根据培养细胞、培养载体、培养液混合方式的不同,生物反应器主要有搅拌式、气升式、中空纤维式、回转式等,其中搅拌式规模最大。回转式是NASA于20世纪90年代中期开发的一种新型生物反应器,被誉为空间生物反应器,可用于组织工程研究。与生物反应器配套的技术主要有灌注、微载体、多孔微球、转入抗凋亡基因等,可以有效地提高细胞密度,增加生物制品产量,提高质量。今后生物反应器研制主要朝两个方向发展:一是,以高密度培养动物细胞生产蛋白质药物为目的,二是以三维培养动物细胞(主要是人类细胞)再生组织或器官为目的。     

光生物反应器培养大型海藻细胞或组织

许多大型海藻含有具潜在重要药用价值的次生代谢物质,通常这些物质在藻体中含量极微,大型海藻体本身也不像微藻那样易在短期内大量获取,并且这些物质化学结构复杂,这使得直接提取或者人工合成极为困难。利用光生物反应器培养大型海藻细胞或组织,可以经济、无限量和资源循环再利用的方式,在植物体外合成生产重要的海洋植物次生代谢物质。光生物反应器所提供的可调控和工程优化的培养环境有望成为优化次生代谢物生物合成的有效手段。光生物反应器培养大型海藻细胞或组织也是大型海藻养殖业育苗技术发展的一个重要方向。综述了近10年来光生物反应器培养大型海藻细胞或组织在培养条件以及生长动力学模型方面国内外的研究进展,并对该领域未来可能的研究方向作一展望。     

流加培养技术

现在有三种生物反应器运转方式,即纯批式、连续式和流加式(fed-batch)或称作半批式,在批式发酵过程中,除要调节pH和在通气培养情况下需供给氧气外,所需要的全部养料在接种前都已存在于培养基中。连续发酵过程中有营养培养基的流入和流出,因此反映器中     

使用旋转式生物反应器体外扩增人表皮细胞

目的:使用Cytodex-3微载体和高截面纵横比的旋转式生物反应器容器作为培养系统大规模扩增人表皮细胞(hECs)。方法:使用中性蛋白酶和胰蛋白酶-EDTA两步骤法从人皮肤中分离出人表皮细胞,使用DIL标记细胞后结合微载体后在旋转式生物反应器(RCCS)中培养,细胞贴附微载体的生长状态使用倒置显微镜,扫描电镜观测。并且分析细胞群体倍增时间来比较微重力培养与平面培养的体外增殖能力差异。结果:在旋转式生物反应器的微重力培养体系中,人表皮细胞能快速贴附到微载体表面,在培养过程中达到很大的细胞密度,并且表现出很强的增殖能力和细胞活性。结论:使用旋转式生物反应器和微载体悬浮培养人表皮细胞,是大量制备皮肤组织工程种子细胞的一种有效方法。     

使用旋转式生物反应器体外扩增人表皮细胞

目的：使用Cytodex-3微载体和高截面纵横比的旋转式生物反应器容器作为培养系统大规模扩增人表皮细胞（hECs）。方法：使用中性蛋白酶和胰蛋白酶．EDTA两步骤法从人皮肤中分离出人表皮细胞,使用DIL标记细胞后结合微载体后在旋转式生物反应器（RCCS）中培养,细胞贴附微载体的生长状态使用倒置显微镜,扫描电镜观测。并且分析细胞群体倍增时间来比较微重力培养与平面培养的体外增殖能力差异。结果：在旋转式生物反应器的微重力培养体系中,人表皮细胞能快速贴附到微载体表面,在培养过程中达到很大的细胞密度,并且表现出很强的增殖能力和细胞活性。结论：使用旋转式生物反应器和微载体悬浮培养人表皮细胞,是大量制备皮肤组织工程种子细胞的一种有效方法。     

植物细胞培养生物反应器的种类特点及展望

生物反应器技术应用于植物细胞培养既可以打破环境条件的限制,又有助于生产过程的人为调控,为植物细胞大规模培养或工厂化直接生产植物细胞有用代谢产物创造了条件,是当前植物细胞培养工作的研究热点。在介绍植物细胞培养特点的基础上,对适用于植物细胞培养的各类生物反应器(搅拌式生物反应器、非搅拌式生物反应器、用于植物细胞固定化培养的生物反应器、光生物反应器以及一次性培养生物反应器)的原理、优缺点等进行比较分析,最后提出了植物细胞培养生物反应器研究的发展方向,以期为植物细胞培养生物反应器的选择及改良提供参考。     

内循环气升式生物反应器培养甘草细胞

自行设计研制了７Ｌ,９Ｌ及２５Ｌ内循环气升式生物反应器,并应用于甘草细胞的放大培养研究。在接种量为８％（Ｗ／Ｖ）通气率为０．２—０．２５ｖｖｍ的条件下,甘草细胞在反应器中生长迅速。其中在９Ｌ反应器中生长最好,最高生物量达１６．２５ｇ／Ｌ,生长速率达０．９ｇ／Ｌ．ｄ,均高于摇瓶培养。培养过程中ｐＨ值、溶氧状况通过电极自动显示记录,说明设计的气升式生物反应器适合于甘草细胞的大规模培养。     

杂交瘤细胞的大量培养

杂交瘤细胞的大量培养是一项迅速发展的技术。本文评述了杂交瘤细胞培养条件和代谢调控方面的研究进展,包括反应器培养中的过程参数优化、细胞损伤和保护、营养物质利用和有害副产物的形成、细胞生长和单抗分泌的动力学以及长期培养的稳定性等问题。同时,本文也讨论了在生物反应器中培养杂交瘤细胞的操作模式和控制策略的研究工作,特别是近年来备受重视的灌注培养和补料培养。     

Agitation,aeration and perfusion modules for cell culture bioreactors

For an optimized bioreactor design which is adapted to the cultivation of sensitive animal cells different modular bioreactor components for gentle agitation, sufficient aeration and long-term perfusion were developed and investigated with respect to their suitability from laboratory to production scale. Aeration systems have been designed for both shear sensitive cells and cells which tolerate bubbles. The systems are based on either membranes for bubble-free aeration or stainless steel sparger systems. They were characterized by determination of their oxygen transfer capacity and optimized in cultivation processes of different cell lines under process conditions such as batch and perfusion mode.Different impellers for suspension cells and cells grown on carriers were investigated for their suitability to ensure homogeneous gentle mixing. A large pitch blade impeller as well as a novel 3-blade segment impeller are appropriate for homogeneous mixing at low shear rates. Especially with the 3-blade segment impeller fluid mechanical stress can be reduced at a given stirrer speed which is advantageous for the cultivation of cells attached to microcarriers or extremely shear sensitive suspension cells. However, our results indicate that shear sensitivity of animal cells has been generally overestimated.Continuous perfusion of both suspension cell cultures and cells cultivated on microcarriers could be successfully performed over extended periods of time using stainless steel spinfilters with appropriate pore sizes and systems based on microporous hydrophilic membranes. Spinfilters are suitable cell retention systems for technical scale bioreactors allowing continuous perfusion cultures of suspension cells (pore size 10 to 20 m) as well as anchorage dependent cells grown on microcarriers (pore size 75 m) over six weeks to 3 months.Applying the developed modules for agitation, aeration and perfusion process adapted bioreactor set-ups can be realized which ensure optimum growth and product formation conditions in order to maximize cell and product yields.     

Two new disposable bioreactors for plant cell culture: The wave and undertow bioreactor and the slug bubble bioreactor

The present article describes two novel flexible plastic-based disposable bioreactors. The first one, the WU bioreactor, is based on the principle of a wave and undertow mechanism that provides agitation while offering convenient mixing and aeration to the plant cell culture contained within the bioreactor. The second one is a high aspect ratio bubble column bioreactor, where agitation and aeration are achieved through the intermittent generation of large diameter bubbles, "Taylor-like" or "slug bubbles" (SB bioreactor). It allows an easy volume increase from a few liters to larger volumes up to several hundred liters with the use of multiple units. The cultivation of tobacco and soya cells producing isoflavones is described up to 70 and 100 L working volume for the SB bioreactor and WU bioreactor, respectively. The bioreactors being disposable and pre-sterilized before use, cleaning, sterilization, and maintenance operations are strongly reduced or eliminated. Both bioreactors represent efficient and low cost cell culture systems, applicable to various cell cultures at small and medium scale, complementary to traditional stainless-steel bioreactors.     

Bioactive metabolite production and stress-related hormones in Devil’s claw cell suspension cultures grown in bioreactors

In a previous report, we showed that cell cultures of Harpagophytum procumbens, a South African plant with high medicinal value, accumulate high amounts of anti-inflammatory phenylethanoid glycosides during cultivation in shake-flasks. The aim of the present study was to transfer the phenylethanoid biosynthetic process to a 3-L stirred tank reactor and a 1-L glass-column bioreactor (operated with pulsed aeration). We found that, with stepwise increases in aeration, the stirred tank reactor yielded similar productivities of verbascoside (the major phenylethanoid glycoside in the cells) to those reported for shake-flask cultures (55.68 vs. 54.78 mg verbascoside/L/day, respectively). Transfer in the pulse-aerated column reactor resulted in 165.42 mg verbascoside/L/day, one of the highest yields reported to date. Further, to evaluate the physiological status of the suspended cells in the bioreactors cultures, we examined their hormone levels and compared them to those of cells in shake-flask cultures. While indole-3-acetic acid levels did not differ significantly between the bioreactor and shake-flask cultures, there were considerable differences in their levels of abscisic, jasmonic, and salicylic acids. These results are discussed with respect to relative stress levels in the different cultivation systems.     

Improving bioreactor cultivation conditions for sensitive cell lines by dynamic membrane aeration

Although the importance of animal cell culture for the industrial (large scale) production of pharmaceutical products is continuously increasing, the sensibility of the cells towards their cultivation environment is still a challenging issue. In comparison to microbial cultures, cell cultures which are not protected by a cell wall are much more sensitive to shear stress and foam formation. Reactor design as well as the selection of ‘robust’ cell lines is particularly important for these circumstances. Nevertheless, even ‘sensitive’ cell lines are selected for certain pharmaceutical processes due to various reasons. These sensitive cell lines have even higher requirements regarding their cultivation environment. Important characteristics for the corresponding reactor design are a high (volumetric) gas mass transfer coefficient, low volumetric power input, low shear stress, low susceptibility to bio-fouling, the ability to cultivate sticky cells and sufficient mixing properties. Membrane aeration has been a long-known possibility to meet some of these requirements, but has not often been applied in recent years. The reasons lie mainly in low gas mass transfer rates, a limited installable volume-specific membrane surface area, restrictions in scalability and problems with membrane fouling. The dynamic membrane aeration bioreactor aeration is a simple concept for bubble-free oxygen supply of such sensitive cultures. It overcomes limitations and draw-backs of previous systems. Consisting of an oscillating, centrally arranged rotor (stirrer) that is wrapped with silicone membrane tubing, it enables doubling the gas mass transfer at the same shear stress in the investigated cultivation scales of 12, 20, 100, and 200 L. Continuous cultivation at these scales allows the same product output as fed-batch cultivation does at tremendously larger reactor volumes. Apart from introducing this novel technology, the presentation comprises selected cultivation results obtained for blood coagulation factor VIII in continuous mode and a therapeutic monoclonal antibody in fed-batch mode in comparison to reference trials.     

Bioprocessing of plant cell cultures for mass production of targeted compounds

More than a century has passed since the first attempt to cultivate plant cells in vitro. During this time, plant cell cultures have become increasingly attractive and cost-effective alternatives to classical approaches for the mass production of plant-derived metabolites. Furthermore, plant cell culture is the only economically feasible way of producing some high-value metabolites (e.g., paclitaxel) from rare and/or threatened plants. This review summarizes recent advances in bioprocessing aspects of plant cell cultures, from callus culture to product formation, with particular emphasis on the development of suitable bioreactor configurations (e.g., disposable reactors) for plant cell culture-based processes; the optimization of bioreactor culture environments as a powerful means to improve yields; bioreactor operational modes (fed-batch, continuous, and perfusion); and biomonitoring approaches. Recent trends in downstream processing are also considered. This paper is dedicated to Prof. Dr. Mladenka P. Ilieva on the occasion of her 70th birthday.     

动物细胞培养用生物反应器设计原理

动物细胞培养用生物反应器设计和放大的关键问题是细胞破损与供氧和混合的矛盾,在分析细胞破损机理基础上,提出了动物细胞培养生物反应器的设计原理——设计模型和有关设计条件,从而清楚地确立了细胞死亡速度与培养基组成、反应器设计和操作参数间的定量关系,以及反应器设计应遵循的保证细胞生长和满足传质要求的条件。还对强化传质和抑制细胞破损这一矛盾作了简要分析和讨论。     

Effects of oxygen on recombinant protein production by suspension cultures of Spodoptera frugiperda (Sf-9) insect cells.

Spodoptera frugiperda (Sf-9) insect cells have been grown in serum-free medium in 250-ml spinner flasks. The maximum cell density obtained in these cultures was dependent on the aeration rate of the culture. Similar yields of uninfected cells were obtained when cultures were stirred in spinner flasks at 80 rev min-1 and in a 4-1 stirred-tank bioreactor and the dissolved oxygen in the bioreactor was controlled at 20% of air saturation. Cells were infected with a recombinant baculovirus at different multiplicities of infection: the timing and maximum level of expression of the recombinant protein were dependent on the multiplicity of infection, the cell density at infection, and on the aeration rate of the culture. Oxygen-limited growth resulted in undetectable levels of recombinant protein (< 6 ng recombinant protein 10(-7) cells). Compared with the maximum yields observed in spinner flask cultures, higher levels of recombinant protein were produced when cells were grown and infected in the bioreactor. The level of dissolved oxygen in the bioreactor was controlled at 50% of air saturation.     

Bioprocess considerations for production of secondary metabolites by plant cell suspension cultures

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stageetc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.     

Cultivation of animal cells in a reticulated vitreous carbon foam.

A reticulated vitreous carbon foam (RVCF) was used as a surface to cultivate a model anchorage-dependent animal cell line, 3T6 (mouse embryo fibroblast). This fixed-surface bioreactor provided a low-shear, chemically-inert, and reusable environment for cell growth. An external medium recirculation loop allowed aeration, nutrient monitoring, and medium replacement without disturbing the cells. Optimal flow rates for the attachment and growth phases were determined. Growth rates comparable to static (T-flask and petri dish) cultures and agitated microcarrier cultures were achieved with appropriately high medium recirculation rates. Metabolic parameters were shown to be useful indicators of cell mass, although specific glucose consumption rates were considerably higher for cultures in the RVCF reactor. Oxygen supply was shown to be the most likely limiting factor for scaleup.     

Development of bioreactors for the culture of surface immobilized plant cells

The scaleup of the technique of plant cell surface immobilization was performed successfully in specifically designed laboratory size bioreactors. The immobilizing matrix was formed into a vertically wound spiral providing for a high immobilizing area-to-volume ratio (0.8-1.2 cm(-1)). A modified airlift and a mechanically stirred vessel delivered a best bioreactor performance characterized by low biomass frothing and highly efficient plant cell attachment and retention (>/=96%). The growth of Catharanthus roseus cells investigated in these bioreactors was found not to be mass transfer limited. It required mild mixing and aeration levels (k(L)a approximately 10-15 h(-1)). The biomass formation pattern of surface immobilized plant cells generally exhibited a linear growth phase followed by a stationary phase characterized by the presence of residual carbohydrates in the medium, contrary to suspension cultures. This behavior was found to depend on the plant cell type and/or line cultured, as well as on the inoculum age. The space restriction and unidirectional growth of the SIPC biofilm combined with the limited availability of essential intracellular nutrients rapidly accumulated from the medium by the stationary phase inoculated plant cells all likely contributed to the culture behavior.