Showing papers on "Bioreactor published in 1987"

Packed bed bioreactor

Abstract: A bioreactor for anchorage or nonanchorage dependent cells or for immobilized enzymes that is capable of achieving high cell densities or concentrations of reaction products is disclosed. The bioreactor is capable of being easily scaled up. The bioreactor utilizes horizontal or radial flow of the culture or growth medium across a packed bed of microcarriers with attached cells or enzymes. The radial flow utilized by the chamber minimizes the non-optimal culture perfusion problems and maximizes the uniformity of medium delivery and cell and/or enzyme viability. The cell culture chamber possess the capability for the production of many industrially important and useful products, particularly in the medical, pharmaceutical, food, agricultural, environmental and purification industries. In the medical and pharmaceutical industries, the large scale production of therapeutically important substances such as anti-tumor factors, hormones, viral antigens, enzymes, interferons and other valuable biomolecules, is greatly facilitated.

Characteristics of draft tube gas-liquid-solid fluidized-bed bioreactor with immobilized living cells for phenol degradation.

Abstract: Biological phenol degradation in a draft tube gas-liquid-solid fluidized bed (DTFB) bioreactor containing a mixed culture immobilized on spherical activated carbon particles was investigated. The characteristics of biofilms including the biofilm dry density and thickness, the volumetric oxygen mass transfer coefficient, and the phenol removal rates under different operating conditions in the DTFB were evaluated. A phenol degradation rate as high as 18 kg/m3-day with an effluent phenol concentration less than 1 g/m3 was achieved, signifying the high treatment efficiency of using a DTFB.

Bioreactor system with solvent extraction for organic acid production.

Abstract: Anaerobic fermentations using renewable resources such as starch and cellulose could represent attractive alternatives to the production of various chemicals. These chemicals include organic acids, alcohols, and ketones. Microbial production has some unique features, which include diversity of metabolism using different substrates, selectivity of catabolism to the desired end product, and efficient conversion during catabolism. On the other hand, there also exist a number of generic problems when these processes are considered for industrial implementation. Two noticeable problems are the low rate of throughput and the difficulty in product recovery. These are often the results of end-product inhibition, which adversely affects productivity and the desired high product concentration. Therefore, new concepts integrating fermentation with product recovery are proposed to address these problems. The lactic acid fermentation using Lactobacillus delbrueckii is chosen as a model system to demonstrate the principles. Extractive fermentation is a technique that can reduce the effect of end-product inhibition through the use of a water-immiscible phase that removes the fermentation products in situ. This can enhance product formation rate and can possibly reduce the product recovery costs. Levy et al.' have shown experimentally that long-chain organic acids such as butyric acid, valeric acid, and caproic acid are extractable by kerosene. However, short-chain organic acids are difficult to extract unless a reactive extraction is employed. In reactive extraction, two component solvents containing diluents and extractants are used. The extractant complexes with the free form of organic acid and then the hydrophobic complex formed is solvated by the diluent. Because free acid is the extractable species, it is important to maintain acidic conditions (pH near pK,) during extractive fermentation. Among the extractants, we have chosen to examine a phosphine derivative (Trioctylphosphineoxide, TOPO) and an aliphatic amine (Trioctylamine, Alamine 336). They have been shown to extract acetic acid from aqueous streams.24 Roffler et al.' have tested TOPO with some diluents for removing lactic acid, while Wennersted has reported extensive data on citric acid extraction by Alamine 336 in combination with different diluents. To be useful in extractive fermentations, the solvents should be compatible with the microorganism. However, the presence of an organic solvent may give rise to a series of physical, microbial, and biochemical effects on the catalytic activity. Organic solvents

Bioreactor system with plasticizer removal

Abstract: An improved hollow fiber bioreactor system is disclosed that includes an arrangement for removing the plasticizer that is typically found within the hollow fibers of hollow fiber cartridges so as to prevent this material from contaminating the nutrient fluid. The plasticizer is removed without jeopardizing sterility of the bioreactor.

Removal of volatile aliphatic hydrocarbons in a soil bioreactor

Abstract: Soil removal of propane, isobutane and n-butane from a waste air stream was evaluated in the laboratory and in a prototype soil bioreactor. Laboratory investigations indicated first-order kinetics and the potential to degrade light aliphatic hydrocarbons and trichlorethylene, a compound ordinarily resistant to aerobic biological treatment. The predicted behavior of the bioreactor, based on laboratory studies, agreed closely with the actual behavior of the Reid system. The prototype bioreactor reduced the hydrocarbon concentrations in the air by at least 90percent with a residence time of 15 minutes and a pressure drop of 85 cm of water. The bioreactor functioned well through a range of temperatures, 12°C to 24°C.

Performance of tapered column packed-bed bioreactor for ethanol production.

Abstract: A tapered column type of bioreactor system packed with immobilized Saccharomyces cerevisiae was used to study the bioreactor performance as a function of design and operating variables. The performance of tapered column bioreactor system was found to be better than that of the conventional cylindrical column reactor system for the ethanol fermentation. The new bioreactor design alleviated problems associated with carbon dioxide evolution and provided a significantly better flow pattern for both liquid and gas phases in the bioreactor without local channelling. A mathematical simulation model, which takes into account of the axial convection and dispersion, interphase mass transfer, and apparent kinetic design parameters, was developed. The effect of radial concentration gradients on the bioreactor performance was found to be insignificant. For the reactor system studied, the maximum ethanol productivity obtained was 60 g ethanol/L gel/h, and the maximum glucose assimilation rate was 140 g glucose/L gel/h. One of the most important findings from this study was that the apparent kinetic parameters change at the glucose concentration of 2 g/L This change was found to be due to the changes in yeast physiology and metabolism. The values of V(m) (') and V(m) (') decreased from 0.8 to 0.39 g ethanol/g cell/h and from 97mM to 11mM, respectively. The substrate inhibition constant was estimated as 0.76M and the product inhibition constant was determined as 113 g ethanol/L The degree of product inhibition showed practically a linear relationship with an increasing ethanol concentration. Based on the hydro-dynamic analysis of the bioreactor system, it was found that the Peclet number, N(Pe) was not a strong function of the flow velocity at low flow rates through the bioreactor system, but its value decreased somewhat at an interstitial velocity greater than 0.03 cm/s. The tapered column bioreactor system showed a much better flow pattern of gas and liquid phases within the reactor, thereby providing a more homogeneous distribution of gas-liquid-solid phases in the reactor without any phase separation.

Bioreactor having a gas exchanger

Abstract: A bioreactor comprising a bioreactor tank, a plurality of transparent cylindrical bodies together making up a light radiator and arranged parallel to each other in the bioreactor tank, a plurality of optical conductors inserted into each of the transparent cylindrical bodies, a light source device for guiding into the optical conductors the visible light ray components of solar rays and/or artificial light rays, and a gas-exchanger for supplying carbon dioxide CO 2 to a micro-organisms suspension in the space between the transparent cylindrical bodies in the bioreactor. A part of the micro-organisms suspension in the bioreactor is returned to the bioreactor through the gas-exchanger, and carbon dioxide CO 2 is supplied to the micro-organisms suspension in the gas-exchanger. The gas-exchanger consists of silicone pipes having microscopic holes through which the returned micro-organisms suspension pass and a hermetically sealed tank into which the silicone pipes are disposed. Carbon dioxide CO 2 at a pressure higher than that of the micro-organisms suspension flows into the silicone pipes upon being supplied to the hermetically sealed tank.

A cross-flow reactor with immobilized pectolytic enzymes for juice clarification.

Abstract: A new system for continuous juices clarification is presented. The bioreactor combines microporous plates commercially available and industrial pectinases immobilized on nylon membranes in a cross-flow configuration. The kinetic behaviour of the reactor for different recirculation flow rates has been determined. Fresh apricot juice has been continuously clarified in the bioreactor with excellent results.

Anaerobic digestion of wood ethanol stillage using upflow anaerobic sludge blanket reactor.

Abstract: The anaerobic digestion of wood ethanol stillage in a UASB reactor was studied. At organic loading rates be low 16 kg COD/m(3) day the reactor performed effectively, achieving soluble COD and BOD removals in excess of 86 and 93%, respectively. Removal of color averaged 40%. At a loading rate of 16 kg COD/m(3) day the methane yield was 0.302 L CH(4) (STP)/g COD removed, and the observed cell yield was 0.112 g VSS/g COD removed. Operation of the reactor at higher loading rates was unsuccessful. Nitrogen, phosphorus, and alkalinity were supplemented. No additions of the essential trace elements Fe, Co, and Ni were required.

Demonstration of a bubble-free annular-vortex membrane bioreactor for batch culture of red beet cells

Abstract: A putative bioreactor, which exploits Taylor-Couette (annular vortex) flow and a gas-permeating membrane, has been constructed and used to culture red beet (Beta vulgaris L.) cells. The cell growth was followed indirectly as sugar uptake by the cells from the medium. The ultimate fresh mass concentration of 93g/l is regarded as proof-of-concept.

Cell-culture bioreactors

Abstract: When contrasted with microbial fermentation, the characteristics having a bearing on the design and operation of cell-culture bioreactors are fragility, steam sensitivity and anchorage requirements of cells, heat lability and foaming of proteins and other components of cell culture media. Design details of agitation and gas supply, bearings, seals and drives, foam control and sterilization, temperature, oxygen and pH control, water, air and gas purification, liquid feeding and level control, gas exhaust analysis and disposal, handling of liquid effluent and bioreactor installation and scale up are given.

Biodegradation of dichloromethane in waste water using a fluidized bed bioreactor

Abstract: Biological treatment of a synthetic waste water containing 120 mM dichloromethane (10.2g/l) was carried out under aerobic conditions using dichloromethane-degrading bacteria as an inoculum. The bacteria were adsorbed to support particles and grown in a fluidized bed bioreactor. Charcoal and sand particles were compared as support materials with regard to abrasion, the maximum degradation rate for dichloromethane and the stability of the biological activity in the system.

Continuous production of acrylamide by Brevibacterium sp. immobilized in a dual hollow fiber bioreactor

Abstract: Acrylamide was continuously produced from acrylonitrile usingBrevibacterium sp. CHl grown and immobilized in a dual hollow fiber bioreactor of 8.0 cm3. The biomass reached as high as 200 gm/L of the space available for the cell growth. The volumetric productivity of the reactor was 88 gm/L. h and the conversion of acrylonitrile varied with acrylonitrile concentration, pH and feed rate.

Online-Prozeßanalyse in Bioreaktoren†

Abstract: Online measurement of bioreactor performance. Recent techniques for characterization of the cell-reactor system are presented, especially online techniques for measurement of three-phase fluid properties, for chemical analysis of the composition of the fermentation medium and the gas phase, and for determination of the cell concentration as well as for the evaluation of the intracellular components and the biological behaviour of the cells. Furthermore, optimization of the sampling point and the sensor arrangement for the measurement of the above properties are also considered.

Bioreactor apparatus with surface aerator screen

Abstract: A bioreactor (10) for cell culture medium is provided including a flask (11) for holding the culture medium (25), a screen (30,33) at or just below the surface (5) of the culture medium, a mover (21) for the screen to cause it to move generally parallel to the surface of the culture medium, and an integral or separate impeller to cause circulation of the culture medium to the surface of the liquid culture medium. The screen (30,33) is preferably on a float (30), and is connected to be driven at different levels of the liquid in the flask.

Apparatus and method for mass transfer involving biological/pharmaceutical media

Abstract: A mass transfer apparatus and method is based upon use of a mass transfer chamber (12), such as a hollow fiber membrane bioreactor, with means to change the directional flow (16) therethrough for enhancement of the mass transfer operation. The invention has particular utility in cell growth systems, where the periodic reversal of flow direction of a nutrient stream passed through the bioreactor equalizes dispersion of cell growth through the bioreactor and enhances the transport of metabolic waste from the cells being grown.

Biooxidation of coal gasification wastewaters using fluidized-bed bioreactors

Abstract: Process condensate wastewaters from two fixed-bed gasifiers have been treated successfully using a laboratory-scale, fixed-film, fluidized-bed bioreactor. Both dilute (1 to 2% raw wastewater) and more concentrated (50% stripped wastewater) were treated continuously for periods of one to three months. Biological activity was stable, recovery from upsets was rapid, and reaction rates were high due to the high concentration of microorganisms retained on the support particles. Removal of phenolics exceeded 99%, and removal of chemical oxygen demand was typically 75 to 85% for the 50% stripped wastewater with a hydraulic residence time in the bed of ˜5 to 7 h. Sludge production rates were comparable to rates in suspended growth systems.

An intercalated-spiral wound hollow fiber bioreactor for the culture of mammalian cells

Abstract: A dual circuit bioreactor is developed; it consists of two intercalated-spiral sets of hollow fibers with alternated dead-ends. The construction is relatively simple, but guarantees uniform distribution of the ‘arterial’ and ‘venous’ circuits. Data are presented to illustrate the ability of the bioreactor to culture a human lymphoblastoid B-cell line.

Treatment of a landfill leachate in powdered activated carbon enhanced sequencing batch bioreactors

Abstract: Addition of powdered activated carbon (PAC) significantly improved treatment of a chemical waste landfill leachate in sequencing batch bioreactors (SBRs). Concentrations for many of the monitored halogenated organic compounds in the effluent were below their respective detection limits. Excellent treatment efficiency was achieved under a variety of operating conditions: wastewater composition, feed rate, hydraulic retention time, organic loading, PAC dosages, biomass and PAC concentrations in the bioreactors. The PAC-SBR performance was unaffected when wastewater feeding was suspended during weekends and holidays. The PAC-SBR treatment cost is much lower than either that of the conventional granular activated carbon adsorption technology or the two-stage process of biodegradation and carbon treatment.