Bioremediation of phenol by a novel partitioning bioreactor using cow dung microbial consortia

A bioreactor has been designed and developed for partitioning of aqueous and organic phases with a provision for aeration and stirring, a cooling system and a sampling port. The potential of a cow dung microbial consortium has been assessed for bioremediation of phenol in a single-phase bioreactor and a two-phase partitioning bioreactor. The advantages of the two-phase partitioning bioreactor are discussed. The Pseudomonas putida IFO 14671 has been isolated, cultured and identified from the cow dung microbial consortium as a high-potential phenol degrader. The methods developed in this study present an advance in bioremediation techniques for the biodegradation of organic compounds such as phenol using a bioreactor. We have also demonstrated the potential of microorganisms from cow dung as a source of biomass.     

核移植技术生产乳腺生物反应器的研究进展

乳腺生物反应器的研制带来了转基因制药业的兴起。但十几年来,显微注射技术一直是生产乳腺生物反应器的唯一实用手段,由于它本身固有的缺点,使得乳腺生物反应器未能有长足的进步。基因打靶与核移植相结合很可能成为生产乳腺生物反应器更有效的途径,它在外源基因定点整合,消除位点效应、降低生产成本、节省时间方面具有明显的优势。     

气升式生物反应器在杂交瘤细胞培养中的应用

前述研究工作基础上,设计开发了10L规模的动物细胞培养用气升式生物反应器。应用该生物反应器悬浮培养杂交瘤细胞．通过平行试验,考察了该反应器设计的合理性和可靠性。结果显示该反应器不存在限制细胞生长、代谢和产物生成的因素,而且细胞破损技彻底消除,表明该气升式生物反应器给细胞生长、代谢和产物生成提供了理想的培养环境,其设计是成功的。     

“Organized stress” for robust scale-up of intensified production process with fed-batch seed bioreactor

Process intensification has been widely used for many years in the mammalian biomanufacturing industry to increase productivity, agility and flexibility while reducing production costs. The most commonly used intensified processes are operated using a perfusion or fed-batch seed bioreactor enabling a higher than usual seeding density in the fed-batch production bioreactor. Hence, as part of the growth phase is shifted to the seed bioreactor, there is a lower split ratio, which increases the criticality of the seed bioreactor and could impact production performance. Therefore, such intensified processes should be designed and characterized for robust process scale-up. This research work is focused on intensified processes with high seeding density inoculated from seed bioreactor in fed-batch mode. The impact of the feeding strategy and specific power input (P/V) in the seed bioreactor and on the production step with two different cell lines (CL1 and CL2) producing two different monoclonal antibodies was investigated. Cell culture performance in the production bioreactor has been improved due to more stressful conditions for the cells in the seed bioreactor and the impact of the production bioreactor P/V on the production performance was limited. This is the first reported study highlighting a positive impact of cellular stress in seed bioreactors on intensified production bioreactor with the introduction of the “organized stress” concept.     

Use of packed bed bioreactors application to ores bioleaching

Summary The behaviour of glass beads, silicagel and activated carbon particles as bacteria supports for using in backed bed bioreactor has been compared. No important difference was found. Additionally the performance of a bioreactor with glass beads was compared with that of a conventional percolating column in the bioleaching of a copper sulphide ore. Results showed higher copper extraction using the bioreactor.     

膜生物反应器的研究进展

膜生物反应器是近年来发展的废水处理新技术,具有活性污泥浓度高、污泥龄长、占地面积小、投资省的特点。利用膜生物反应器进行污水处理不仅可以大大节约水资源,还可以大大节约能源,节省设备和运行费用,已成为二十一世纪研究热点。膜生物反应器是通过高效膜分离技术与活性污泥相结合,增大污泥中的特效菌来加快生化反应速率,提高废水处理效果。目前处理对象已从生活污水扩展到高浓度的有机废水和难降解的工业废水。本文综述了膜生物反应器在废水中的应用研究情况,并分析比较了各种膜材质的特点、适用范围以及膜的污染因素和清洗方法,展望了膜生物反应器的应用前景及进一步研究方向。     

Treatment of urban wastewater in a membrane bioreactor at high organic loading rates.

Membrane bioreactors can replace the activated sludge process and the final clarification step in municipal wastewater treatment. The combination of bioreactor and crossflow microfiltration allows for a high chemical oxygen demand (COD) reduction of synthetic wastewater. From biomass, grown at high production rates in the aerobic bioreactor, energy rich biogas can be obtained in a subsequent anaerobic bioreactor. In this paper, experimental data from a laboratory scale membrane bioreactor are presented. The degradation of synthetic wastewater at short hydraulic retention times down to 1.5 h has been studied. The organic loading rate (OLR) has been varied in the range of 6-13 kg m(-3) per day. At steady state a high quality filtrate could be obtained at different operating conditions. At biomass concentrations of 10-22 g l(-1), COD reduction was above 95%.     

Enzymatic resolution of (S)-(+)-naproxen in a continuous reactor

An enzymatic method for the continuous production of (S)-(+)-2-(6-methoxy-2-naphthyl) propionic acid (Naproxen) has been developed. The process consists of a stereoselective hydrolysis of the racemic Naproxen ethoxyethyl ester catalyzed by Candida cylindracea lipase. The reaction has been carried out in a continuous-flow closed-loop column bioreactor packed with Amberlite XAD-7, a slightly polor resin on which the lipase has been immobilized by adsorption. Various immobilization conditions as well as the properties of the immobilized lipase have been studied. The performance and the productivity of the bioreactor were evaluated as a function of the critical reaction parameters such as temperature, substrate concentration, and product inhibition. By using a 500-mL column bioreactor, 1.8 kg of optically pure (S)-(+)-Naproxen were produced after 1200 h of continuous operation with a slight loss of the enzymatic activity.     

Process challenges relating to hematopoietic stem cell cultivation in bioreactors

Hematopoietic stem cells (HSCs) are extremely useful in treating a wide range of diseases and have a variety of useful research applications. However, the routinely generated low in vitro concentrations of HSCs from current bioreactor manufacturing systems has been a hindrance to the full-scale application of these essential cellular materials. This has made the search for novel bioreactor systems for high-concentration HSC production a major research endeavour. This review addresses process challenges in relation to bioreactor development and optimisation for high-density HSC production under effective monitoring of essential culture parameters, such as pH, dissolved oxygen and nutrient uptake. It discusses different process strategies and bioreactor configurations for HSCs production from a commercial viability perspective, and also discusses recent advances in the field.     

Scale-up of biotransformation process in stirred tank reactor using dual impeller bioreactor

The gas-liquid mass transfer coefficient K(L)a in the fermenter is a strong function of mode of energy dissipation and physico-chemical properties of the liquid media. A combination of disc turbine (DT) and pitched blade turbine down flow (PTD) impellers has been tested in laboratory bioreactor for gas hold-up and gas-liquid mass transfer performance for the growth and biotransformation medium for an yeast isolate VS1 capable of biotransforming benzaldehyde to L-phenyl acetyl carbinol (L-PAC) and compared with those in water.Correlations have been developed for the prediction of the fractional gas hold-up and gas-liquid mass transfer coefficient for the above media. The mass transfer coefficient and respiration rate have been determined in the shake flask for the growth as well as for biotransformation medium. These results, then have been used to optimize the operating parameters (impeller speed and aeration) for growth and biotransformation in a laboratory bioreactor. The comparison of cell mass production and L-PAC production in the bioreactor has been done with that obtained in shake flask studies.     

Development of bioreactor systems with functional bio-carrier modified by disperse turquoise blue S-GL for disperse scarlet S-BWFL decolorization

The effect of redox mediator has been studied in details in the bio-decolorization processes, but there are little literatures about bioreactor systems with functional bio-carrier modified by redox mediator. Two different bioreactor configurations (bioreactor R1 with functional bio-carrier modified by disperse turquoise blue S-GL (as redox mediator) and bioreactor R2 with non-modified bio-carrier) were designed and tested for disperse scarlet S-BWFL decolorization by Halomonas sp. GYW (EF188281) in this study. Influencing factors such as co-substrate, temperature and pH were optimized through batch experiments. Compared to bioreactor R2, bioreactor R1 exhibited good decolorization efficiency and performance ability for the disperse scarlet S-BWFL decolorization, which showed higher decolorization efficiency (over 96% color removal with 0.8 g L(-1) dye concentration) and less hydraulic retention time to attain the same decolorization efficiency. The combinational technology of redox mediator and bio-carrier was a new bio-treatment concept and a great improvement for the application of redox mediator.     

A bioactive foamed emulsion reactor for the treatment of benzene-contaminated air stream

An adapted bioactive foamed emulsion bioreactor for the treatment of benzene vapor has been developed. In this reactor, bed clogging was resolved by bioactive foam as a substitute of packing bed for interfacial contact of liquid to gaseous phase. The pollutant solubility has been increased using biocompatible organic phase in liquid phase and this reactor can be applied for higher inlet benzene concentration. Experimental results showed a benzene elimination capacity (EC) of 220 g m⁻³ h⁻¹ with removal efficiency (RE) of 85% for benzene inlet concentration of 1–1.2 g m⁻³ at 15 s gas residence time in bioreactor. Assessment of benzene concentration in liquid phase showed that a significant amount of transferred benzene mass has been biodegraded. By optimizing the operational parameters of bioreactor, continuous operation of bioreactor with high EC and RE was demonstrated. With respect to the results, this reactor has the potential to be applied instead of biofilter and biotrickling filters.     

Pyridine biodegradation in a novel rotating rope bioreactor

A novel immobilised bioreactor has been developed especially for the treatment of pollutants characterized by high volatility along with high water solubility and low microbial yields. The new bioreactor referred to as the rotating rope bioreactor (RRB) provides higher interfacial area (per unit reactor liquid volume) along with high oxygen mass transfer rate, greater microbial culture stability; and consequently higher substrate loadings and removal rates in comparison to other conventional rectors for the treatment of volatile compounds. Pyridine was used as a model compound to demonstrate the enhanced performance with RRB, when compared to that reported with other conventional bioreactors. The experimental results indicate that the novel RRB system is able to degrade pyridine with removal efficiency of more than 85% at higher pyridine concentration (up to 1000 mg/l) and loading [up to 400 mg/m(2)/h (66.86 g/m(3)/h)], with a shorter hydraulic retention time (9-18 h). The reactor has been in operation for the past 15 months and no loss of activity has been observed.     

Methods for Baculovirus Amplification - Application to Large Scale Recombinant Protein Production in Insect Cells

Baculovirus amplification in one insect cell line Spodoptera frugiperda (Sf21) and subsequent recombinant protein production in another cell line, Trichoplusia ni, has been achieved within a single bioreactor. The advantages of this single bioreactor configuration include minimization of the virus volumes and titres required for large scale protein expression experiments as well as optimization of the infection process itself.     

Biodegradation of Phenol Using Immobilized Nocardia hydrocarbonoxydans in a Pulsed Plate Bioreactor: Effect of Packed Stages,Cell Carrier Loading,and Cell Acclimatization on Startup and Steady-State Behavior

The effect of the number of stages and cell carrier loading on the steady-state and startup performance of a continuous pulsed plate bioreactor with glass beads as the cell carrier material for biodegradation of phenol in wastewater using immobilized Nocardia hydrocarbonoxydans has been studied. It was found that the performance of the pulsed plate bioreactor during startup and at steady state can be improved by an increase in cell carrier loading, number of stages, total plate stack height, and with a decrease in plate spacing. The startup time for the continuous bioreactor can be decreased by increasing the number of preacclimatization steps for the cells. The attainment of steady effluent phenol concentration can be considered as an indication of steady state of the continuous bioreactor, as when phenol concentration attained a steady value, biofilm thickness, and the attached biomass dry weight also attained a constant value.     

利用植物生物反应器生产药用蛋白质

植物生物反应器是一种安全、环保、廉价的生产系统。它已成为生产药用蛋白质的理想载体并受到广泛的关注。目前,生物反应器通过靶向表达来提高外源蛋白质产量取得了一定的效果。本文简要介绍了生物反应器的选择,并着重阐述了通过在空间上的定位表达和时间上的诱导表达来提高药用蛋白质产量方面的最新研究进展,同时展望了未来的发展前景。     

New developments in solid-state fermentation: II. Rational approaches to the design, operation and scale-up of bioreactors

Over the last decade there has been a significant improvement in understanding how to design, operate and scale-up solid-state fermentation bioreactors. The key to these advances has been the application of mathematical modeling techniques to describe the biological and transport phenomena within the system. This review focuses on the advances in understanding that have come from this modeling work, and the insights it has given us into bioreactor design, operation and scale-up. It also highlights two promising bioreactor designs that have emerged over the last decade or so. For processes in which the substrate bed must remain static throughout the fermentation, the most promising design is the Zymotis design of ORSTOM at Montpellier, France, which involves closely spaced internal heat transfer plates within a packed-bed bioreactor. For those processes in which mixing can be tolerated, the stirred bioreactor developed at INRA, in Dijon, France, has been successfully demonstrated at scales of 1–25 t of substrate. Theoretical work suggests that mathematical models will be useful tools in the scale-up process, however, there are no reports that they have been used in the development of any current large-scale process. Rather, the models have been validated against data obtained from laboratory-scale bioreactors. There is an urgent need to test the accuracy and robustness of the models by applying them within real process development.     

Enhanced removal of dimethyl sulfide from a synthetic waste gas stream using a bioreactor inoculated with <Emphasis Type="Italic">Microbacterium</Emphasis> sp. NTUT26 and <Emphasis Type="Italic">Pseudomonas putida</Emphasis>

The removal of dimethyl sulfide (DMS) from industrial gas streams has received a high priority due to its very low odorous threshold value and relatively low biodegradability compared to other reduced sulfur compounds. A variety of bacteria that utilize DMS as a carbon/energy source have been studied and the degradation pathway elucidated. However, to date, there have been few reports on the industrial application of such bacteria inoculated into a bioreactor for DMS treatment. An additional problem of such systems is the accumulation of intermediate metabolites that strongly impact on DMS removal by the microbe. The results reported here were obtained using a bioreactor inoculated with the H(2)S-degrader Pseudomonas putida and the DMS-degrader Microbacterium sp. NTUT26 to facilitate removal of metabolic intermediates and DMS. This bioreactor performed well (1.71 g-S/day/kg-dry packing material) in terms of DMS gas removal, based on an evaluation of the apparent kinetics and maximal removal capacity of the system. Under varying conditions (changes in start-up, inlet loading, shutdown, and re-start), the bioreactor inoculated with Microbacterium sp. NTUT26 and P. putida enhanced removal of high concentrations of DMS. Our results suggest that this type of bioreactor system has significant potential applications in treating (industrial) DMS gas streams.     

Periodic operation of immobilized live cell bioreactor for the production of candicidin

A lumped model for cell growth and secondary metabolite production in an immobilized live cell bioreactor has been developed. This model is applied here to simulate the performance of an immobilized bioreactor under steady-state conditions and under conditions of periodically varying concentration of a growth-limiting substrate. The results of the simulation study were experimentally verified in the case of the production of the antibiotic candicidin by Streptomyces griseus in an immobilized bioreactor with forced periodic operation. The results of the studies suggest that periodically operated immobilized live cell bioreactors can provide a potent alternative for the production of non-growth-associated biochemicals, as compared to free cell fermentations, pulsed fermentations with process cycle regeneration, and nonregenerated bioreactors. This work has demonstrated that by frequent pulsing of the growth limiting nutrient, stable extended production can be obtained at high specific cellular productivities.     

Oxygenation capabilities of basket-type bioreactors for microcarrier cultures of anchorage-dependent cells

The oxygenation capabilities of a new generation three phase – two region 1200 l bioreactor employed for the cultivation of anchorage dependent animal cells were investigated experimentally. A mathematical model has also been developed that explains qualitatively the observed oxygenation characteristics. This type of bioreactor, that uses microcarrier support particles, has two distinct mesh-separated regions so that the air bubbles in the oxygenation region do not come into contact with the microcarriers in the cell (bubble-free) region. Implications on achievable maximum cell densities are also discussed.