Showing papers on "Bioreactor published in 1991"
Book•
07 Jan 1991
TL;DR: Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering with an emphasis on enzyme reactors and aerated reactors for microorganisms.
Abstract: Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering, with an emphasis on enzyme reactors and aerated reactors for microorganisms. Includes exercises.
377 citations
TL;DR: The detailed investigation of stimulatory and repressory effects of simple and complex nutrients on protease production and metabolism of Bacillus firmus conducted in this study will provide useful guidelines for design of bioreactors for production of protease and bulk chemicals by this bacterium.
Abstract: Proteolytic enzymes produced by Bacillus species find a wide variety of applications in brewing, detergent, food, and leather industries. Owing to significant differences normally observed in culture conditions promoting cell growth and those promoting production of metabolites such as enzymes, for increased efficacy of bioreactor operations it is essential to identify these sets of conditions (including medium formulation). This study is focused on formulation of a semidefined medium that substantially enhances synthesis and secretion of an alkaline protease in batch cultures of Bacillus firmus NRS 783, a known superior producer of this enzyme. The series of experiments conducted to identify culture conditions that lead to improved protease production also enables investigation of the regulatory effects of important culture parameters including pH, dissolved oxygen, and concentrations of nitrogen and phosphorous sources and yeast extract in the medium on cell growth, synthesis and secretion of protease, and production of two major nonbiomass products, viz., acetic acid and ethanol. Cell growth and formation of the three nonbiomass products are hampered significantly under nitrogen, phosphorous, or oxygen limitation, with the cells being unable to grow in an oxygen-free environment. Improvement in protease production is achieved with respect to each culture parameter, leading in the process to 80% enhancement in protease activity over that attained using media reported in the literature. Results of a few fed-batch experiments with constant feed rate, conducted to examine possible enhancement in protease production and to further investigate repression of protease synthesis by excess of the principal carbon and nitrogen sources, are also discussed. The detailed investigation of stimulatory and repressory effects of simple and complex nutrients on protease production and metabolism of Bacillus firmus conducted in this study will provide useful guidelines for design of bioreactors for production of protease and bulk chemicals by this bacterium.
193 citations
TL;DR: An enzymatic method for the continuous production of (S)−(+)−2−(6‐methoxy‐2‐naphthyl) propionic acid (Naproxen) has been developed and 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.
Abstract: 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.
109 citations
TL;DR: The authors reviewed different types of bioreactor which have been described and used for various purposes, incorporating several modification for improved operation and performance for solid-state fermentations, which have gained importance recently due to several advantages over submerged fermentations.
102 citations
TL;DR: The mixing and oxygenation conditions of this bioreactor were suitable for insect cell culture and recombinant protein production, with limitation being mainly attributed to nutrient depletion and toxic by‐product generation.
Abstract: An 11-L helical ribbon impeller (HRI) bioreactor was tested for the culture of Spodoptera frugiperda (Sf-9) cells. This impeller and surface baffling ensured homogeneous mixing and high oxygen transfer through surface aeration and surface-induced babble generation. Serum-supplemented and serum-free cultures, using TNMFH and IPL/41 media, respectively, grew a similar specific growth rates(0.031 and 0.028 h(-1)) to maximum cell densities of 5.5 x 10(6)-6.0 x 10(6) cells. mL(-1) with viability exceeding 98% during exponential growth phase. Growth limitation coincided with glucose and glutamine depletion and production of significant amounts of alanine. The bioreactor was further tested under more stringent conditions by infecting a serum-free medium culture with a recombinant baculovirus. Heterologous protein production of approximately 35 microg per 10(6) cells was comparable to yields obtained in serum-free cultures grown in spinner flasks and petri dishes. Average specific oxygen up-take and carbon dioxide production rates of the serum-free culture prior to infection as measured by on-line mass spectroscopy were 0.20 micromol O(2).(10(6) cells)(-1) h(-1) and 0.22 micromol CO(2) . (10(6) cells)(-1)h(-1) and increased by 30-40% during infection. Therefore, the mixing and oxygenation conditions of this bioreactor were suitable for insect cell culture and recombinant protein production, with limitation being mainly attributed to nutrient depletion and toxic by-product generation.
98 citations
TL;DR: In this article, the performance of both dispersed gas phase and dispersed liquid phase systems under both mass transfer controlled and non-mass transfer controlled conditions was examined. But the performance was limited to a few minutes for these gaseous substrate fermentations.
88 citations
ENEA1
TL;DR: In this article, the anaerobic digestion of high strength molasses wastewater (molasses alcohol stillage and raw molasses) in a hybrid anaerobically baffled reactor was studied.
81 citations
TL;DR: Mixed culture of microorganisms immobilized onto Celite diatomaceous earth particles were used to degrade 3,4‐dichloroaniline (34DCA) in a three‐phase draft tube fluidized bed bioreactor and a mathematical model was found to describe the system well and to predict qualitatively the experimentally observed transition in the biofilm kinetics from 34DCA to oxygen limitation.
Abstract: Mixed culture of microorganisms immobilized onto Celite diatomaceous earth particles were used to degrade 3,4-dichloroaniline (34DCA) in a three-phase draft tube fluidized bed bioreactor. Biodegradation was confirmed as the dominant removal mechanism by measurements of the concomitant chloride ion evolution. Degradation efficiencies of 95% were obtained at a reactor retention time of 1.25 h. A mathematical model was used to describe the simultaneous diffusion and reaction of 34DCA and oxygen in the biofilms on the particles in the reactor. The parameters describing freely suspended cell growth on 34DCA were obtained in batch experiments. The model was found to describe the system well for three out of four steady states and to predict qualitatively the experimentally observed transition in the biofilm kinetics from 34DCA to oxygen limitation.
74 citations
TL;DR: It was concluded that P. laminosum immobilized on polymer foams is of potential value for biological nitrate removal in a continuous-flow system.
Abstract: Cells of the non-N2-fixing cyanobacteriumPhormidium laminosum were immobilized in polyurethane (PU) foams either by absorption or by entrapment in the PU prepolymer followed by polymerisation and by adsorption onto polyvinyl (PV) foams. Although entrapment caused toxicity problems which lead to rapid death of the immobilized cells, they were immobilized successfully by adsorption onto PU or PV foams and maintained their photosynthetic electron transport activities (PS I, II, I + II) for at least 7 weeks. Changes in the morphology resulting from immobilization, as revealed by scanning electron microscopy (SEM) and low temperature-SEM, were investigated. Batch cultures and a continuous-flow packed bed photobioreactor were used to study nitrate removal from water. The effects of light intensity and CO2 concentration on bioreactor performance were studied with respect to the nitrate uptake efficiency of the system. It was concluded thatP. laminosum immobilized on polymer foams is of potential value for biological nitrate removal in a continuous-flow system.
71 citations
TL;DR: Reactor design did not appear to be as important as the wastewater composition in causing changes to the microbial communities and statistical analysis showed no significant difference between the numbers in each reactor and with respect to time after start-up.
70 citations
Book•
01 Jan 1991
TL;DR: Discussion of conventional and airlift bioreactor design, instrumentation, control and simulation, bioreactors for plant and animal culture and a descriptions of experiments.
Abstract: Discusses many aspects of bioreactor use and design in biotechnology. There is coverage of conventional and airlift bioreactor design, instrumentation, control and simulation of bioreactor runs, bioreactors for plant and animal culture and a descriptions of experiments.
TL;DR: A concentric‐cylinder airlift reactor, in which the annulus is a packed bed of glass fibers, has been developed in order to facilitate the scaleup and enhance the volumetric productivity of anchorage‐dependent animal cell cultures.
Abstract: A concentric-cylinder airlift reactor, in which the annulus is a packed bed of glass fibers, has been developed in order to facilitate the scaleup and enhance the volumetric productivity of anchorage-dependent animal cell cultures. In this bio-reactor, oxygen-containing gas is sparged through the inner draft tube, causing bubble-free medium to flow through the fiber bed in the outer cylinder and providing both oxygenation and convective nutrient transfer to the cells. Several other desirable features for reactor operation are also provided by this design. Cell cultivations in this bioreactor have been successfully carried out and provide data for the feasibility of the large-scale cell cultivation.
TL;DR: The sugars in extracts of dates were converted into ethanol by S. cerevisiae and the subsequent production of acetic acid from the fermented date juice was conducted with Acetobacter aceti, with results more than eight times better than that of a batch process.
TL;DR: Industrial use of membrane bioreactors is still in its infancy and limited to enzyme and animal tissue culture, but applications will expand as existing problems are resolved.
Abstract: Membrane bioreactors have a very handy in-situ separation capability lacking in other types of bioreactors. Combining various functions of membrane separations and biocatalyst characteristics of enzymes, microbial cells, organelles, animal and plant tissues can generate quite a number of membrane bioreactor systems. The cell retaining property of membranes and selective removal of inhibitory byproducts makes high cell density culture possible and utilizes enzyme catalytic activity better, which leads to high productivity of bioreactors. Enzyme reactions utilizing cofactors and hydrolysis of macromolecules are advantageous in membrane bioreactors. Anaerobic cell culture may be efficiently carried out in membrane cell recycle systems, while aerobic cultures work well in dual hollow fiber reactors. Animal and plant cells have much a better chance of success in membrane reactors because of the protective environment of the reactor and the small oxygen uptake rate of these cells. Industrial use of these reactors are still in its infancy and limited to enzyme and animal tissue culture, but applications will expand as existing problems are resolved.
Book•
01 Jan 1991
TL;DR: Historical development of animal cell bioreactors implications of cell biology on bioreactor operation anchorage - dependent cell supports animal cellBioreactor design, operation and control.
Abstract: Historical development of animal cell bioreactors implications of cell biology on bioreactor operation anchorage - dependent cell supports animal cell bioreactor design, operation and control.
TL;DR: In this article, a pilot-scale study of thermophilic anaerobic digestion of high-strength wastewater (evaporator condensate, EC) discharged from a kraft pulp production process was performed.
TL;DR: Investigation into the effect of increasing maximum shear stress on cultures of Catharanthus roseus IDI grown in bioreactors both with and without baffles indicated that cultures were adversely affected by a certain level ofShear stress which resulted in lower biomass and alkaloid accumulation.
TL;DR: In a fed-batch procedure production of alkaline serine protease with Bacillus licheniformis in a synthetic medium could be increased 4.6-fold in comparison to an uncontrolled batch process.
Abstract: A production method for alkaline serine protease with Bacillus licheniformis in a synthetic medium was developed. Employing closed-loop control of oxygen, nitrogen and carbon source the pO2 was held at 5%, the ammonium concentration kept below 1 mM and the glycerol concentration was maintained between 20 and 100 mM. Protease production was monitored by flow injection analysis. Thus, in a fed-batch procedure production could be increased 4.6-fold in comparison to an uncontrolled batch process.
TL;DR: This study shows that the plant cell density in the bioreactor can be greatly improved by feeding with a monosaccharide as the carbon source in fed-batch culture.
TL;DR: Results obtained for the conversion of synthesis gas to CH4 in 5- cm- and 16.5-cm-diameter trickle-bed reactors are compared and light requirements for R. rubrum are considered in bioreactor design.
Abstract: Carbon monoxide, H2, and CO2 in synthesis gas can be converted to CH4 by employing a triculture ofRhodospirillum rubrum, Methanosarcina barken, andMethanobacterium formicicum. Trickle-bed reactors have been found to be effective for this conversion because of their high mass-transfer coefficients. This paper compares results obtained for the conversion of synthesis gas to CH4 in 5-cm- and 16.5-cm-diameter trickle-bed reactors. Mass-transfer and scale-up parameters are defined, and light requirements forR. rubrum are considered in bioreactor design.
TL;DR: In this article, the performance of both dispersed gas phase systems (CSTR) and dispersed liquid phase systems under mass transfer controlled and non-mass transfer controlled conditions was examined. And the authors developed a model to predict bioreactor behavior.
Abstract: Bacterial cultures have been isolated for the conversion of synthesis gas (CO, H2 and CO2) into ethanol or methane. These heterogeneous reactions require the transport of substrate through the gas phase, across the interface into the liquid phase, and to the solid microorganisms. The reactions are generally mass transfer limited due to very low gas solubilities. Bioreactors must maximize mass transport, while achieving high cell densities to promote fast reaction. This paper examines the performance of both dispersed gas phase systems (CSTR) and dispersed liquid phase systems (immobilized cell reactors) under mass transfer controlled and non-mass transfer controlled conditions. Mass transfer coefficients are determined and models are developed to predict bioreactor behavior. Retention times of a few minutes are achieved for these gaseous substrate fermentations.
TL;DR: Cellulose was hydrolyzed in the attrition bioreactor (ABR) with enzyme recycling by employing an aqueous two‐phase system (composed of dextran and polyethylene glycol) and an ultrafiltration unit and the cellulase enzymes were more stable in the two‐ phase system than in the normal buffer solution.
Abstract: Cellulose was hydrolyzed in the attrition bioreactor (ABR) with enzyme recycling by employing an aqueous two-phase system (composed of dextran and polyethylene glycol) and an ultrafiltration unit. The ABR combines wet ball milling and enzymatic hydrolysis in one process step. The cellulase enzymes were more stable in the two-phase system than in the normal buffer solution. With the initial substrate concentration (Solka Floe BW200) of 40 g/L and intermittent addition of cellulose, sugar was semicontinuously produced at dilution rates of 0.06 h−1 and productivities of 2.1 g/L h, which is approximately a 10-fold increase of the previously reported values performed in a regular stirred reactor with an aqueous two-phase system. The conversion of the substrate was 86%.
TL;DR: Both biomass wasting and purging of the membrane oxygenation system were critical for maintaining adequate oxygen transfer to the biofilm in the GAC-SBBR and in the SBBR.
Abstract: The Granular Activated Carbon-Sequencing Batch Biofilm Reactor (GAC-SBBR), a system which combines a submerged membrane oxygenation system to support a biofilm with granular activated carbon (GAC), and the Sequencing Batch Biofilm Reactor (SBBR), a comparable system containing no GAC, were investigated to determine the efficiency of each for the treatment of wastewaters containing volatile components. Toluene, at feed concentrations between 100 and 200 mg/L, was reduced to less than 10{mu}g/L in both systems. In the GAC-SBBR, biodegradation and adsorption were responsible for 92% and 8%, respectively, of the toluene removal, while in the SBBR, all of the toluene was removed by biodegradation. The quantity of toluene volatilized from the GAC-SBBR over a 10 week period of operation was approximately 0.003% of the toluene introduced. The major consideration for long-term, efficient operation of these systems is selection of an operating strategy which results in the supply of sufficient oxygen to the biomass. Both biomass wasting and purging of the membrane oxygenation system were critical for maintaining adequate oxygen transfer to the biofilm in the GAC-SBBR and in the SBBR.
Patent•
12 Feb 1991
TL;DR: In this article, a unique hollow fiber multiple bioreactor system and method for the propagation of cells and the production of various cell propagation products is described, which includes use of a flow block holder which allows a dissolved oxygen probe to be calibrated at the same pressure as the media in the bioreactors.
Abstract: A unique hollow fiber multiple bioreactor system and method for the propagation of cells and the production of various cell propagation products is described. Simultaneous fluid flow through lumens of hollow fibers in bioreactors is maintained constant across multiple bioreactors so production is maintained essentially constant. The system and method include use of a flow block holder which allows a dissolved oxygen probe to be calibrated at the same pressure as the media in the bioreactor system.
TL;DR: Experimental observations indicate that the biofilm formation process is initiated by methanogenic bacteria.
Abstract: The effect of various operating variables such as initial inoculum circulation, dilution rate, chemical oxygen demand (COD) loading rate, and quantity and quality of inoculum on the process of film formation on sand surface and reactor performance were studied using synthetic glucose based wastewater. It was found that the film formation process is favored by a high dilution rate, a large quantity of inoculum, and an inoculum having high methane producing capacity. Experimental observations indicate that the biofilm formation process is initiated by methanogenic bacteria.
TL;DR: In this article, high-strength wastewater from beer breweries was found not to respond well to treatment by a mono-phase thermophilic methane fermentation process using an anaerobic fluidized-bed reactor.
TL;DR: Results of this research show the feasibility of using the CCBR for both production of secreted products and as a research tool for studying cell metabolism and production kinetics.
Abstract: A continuous centrifugal bioreactor (CCBR), developed to study the growth and productivity of dense suspensions cultures, has been applied to both fermentation and mammalian cell cultivation processes. With this approach, high-density nonflocculent cultures are maintained in a tapered fluidized bed by balancing the drag forces on the cells due to following substrate with the centrifugal forces. The Sysyem was first used to produce ethanol by fermentation with Saccharomyces cerevisiae; then with H21A1 mouse hybridoma cells secreting monoclonal antibody (MoAb), lgM. Results of this research show the feasibility of using the CCBR for both production of secreted products and as a research tool for studying cell metabolism and production kinetics. Media recycle may be used to modify the behavior of the system form a plug flow apparatus to a continuous stirred reactor (CSTR).
TL;DR: An examination into the effect of bioreactor design on the production of β,1,3-glucan exopolysaccharide (“curdlan”) by selected patent cultures revealed that low shear mixing achieved through the replacement of the radial-flow flat-blade impellers, leads to an increase in the quality of the exopolymer recovered during the stationary-phase of batch fermentations.
Abstract: An examination into the effect of bioreactor design on the production of β,1,3-glucan exopolysaccharide (“curdlan”) by selected patent cultures ofAlcaligenes faecalis andAgrobacterium radiobacter revealed that low shear mixing achieved through the replacement of the radial-flow flat-blade impellers that are commonly supplied in “standard” commercial bioreactors, by low shear (high-pumping) axialflow impellers, leads to an increase in thequality of the exopolymer recovered during the stationary-phase of batch fermentations. Whereas “Rushton turbine” impellers were effective in providing high rates of oxygen transfer necessary for high cell density fermentations, the high shear-to-flow ratio characteristic of this design produced a product of inferior quality, but with characteristics very similar to that of the commercially available “curdlan standard.” Curdlan is water insoluble, and consequently, the fermentation broth is of a relative low viscosity compared to other soluble microbial polysaccharides. Whereas curdlan does not constrain mass transfer from gas to liquid, it nevertheless offers a resistance to oxygen transfer from the liquid to the cell by virtue of the layer of insoluble exopolymer surrounding the cell mass, thereby necessitating an unexpectedly high dissolved oxygen concentration for maximal productivity. The requirement for high volumetric oxygen transfer can be met by low shear designs with axial-flow impellers, providing gas dispersion is assisted by the use of sparging devices consisting of microporous materials.
Patent•
11 Jun 1991
TL;DR: In this paper, a biochemical process system and apparatus for removal of toxic volatile organic compounds (VOCs), volatile inorganic compounds, heavy metals, and surfactants from contaminated soil, liquid and gas streams, by means of combined washing, pH adjustment, biochemical reaction, gas stripping, scrubbing, adsorption and regeneration is described.
Abstract: A biochemical process system and apparatus for removal of toxic volatile organic compounds (VOCs), volatile inorganic compounds (VICs), heavy metals, and surfactants from contaminated soil, liquid and gas streams, by means of combined washing, pH adjustment, biochemical reaction, gas stripping, scrubbing, adsorption and regeneration is described. This process system involves soil washing with surfactant, soil-water separation, liquid pumping; liquid treatment using an enclosed gas stripping bioreactor and dissolved air flotation technology; gas purification using a foam collector, a wet scrubber and a self-regenerative gas-phase granular activated carbon (GAC) contactor; and recycling of GAC-purified gas for further liquid treatment by gas stripping and biochemical reactions. The process system is extremely cost-effective for removal of both volatile and nonvolatile pollutants from a contaminated site and eliminates the problem of secondary gas contamination caused by conventional air stripping towers.