Showing papers on "Bioreactor published in 1983"

Bioconversion of waste cellulose by using an attrition bioreactor.

Abstract: A new type of reactor, an attrition bioreactor, was tested to achieve a higher rate and extent of enzymatic saccharification of cellulose than is possible with conventional methods. The reactor consisted of a jacketted stainless-steel vessel with shaft, stirrer, and milling media, which combined the effect of the mechanical action of wet milling with cellulose hydrolysis. The substrates tested were newsprint and white-pine heartwood. The performance of the reactor was excellent. The extent and rate of enzymatic hydrolysis could be markedly improved over other methods. The power consumption of the attrition bioreactor was also measured. The cellulase enzyme deactivation during attrition milling was not significant.

Bioreactors: Design and Operation

Abstract: The bioreactor provides a central link between the starting feedstock and the product. The reaction yield and selectivity are determined by the biocatalyst, but productivity is often determined by the process technology; as a consequence, biochemical reaction engineering becomes the interface for the biologist and engineer. Developments in bioreactor design, including whole cell immobilization, immobilized enzymes, continuous reaction, and process control, will increasingly reflect the need for cross-disciplinary interaction in the biochemical process industry.

Ethanol production using Zymomonas mobilis immobilized on an ion exchange resin

Abstract: Ten ion exchange resins as well as activated carbon and ceramic chips were examined for their ability to adsorb cells of Zymomonas mobilis. A cationic macroreticular resin was shown to be the most efficient adsorbant and was used to immobilize cells of Z. mobilis in a column bioreactor. The bioreactor was operated with a feed glucose concentration of 100 g/L at a dilution rate of 11.2 h-1 and a productivity based on void volume of 377 g ethanol/L-h was obtained with 80% substrate utilization. It was observed that the cell concentration in the bioreactor increased during continuous operation and that the form of Z. mobilis changed from single cells to filamentous forms of the bacterium. Plugging problems occurred after 200 h of operation as a result of excessive filamentous cell growth.

A high-performance membrane bioreactor for continuous fermentation of lactose to ethanol

Abstract: Productivity of the fermentation of lactose to ethanol byKluyveromyces fragilis has been significantly improved by coupling a cross-flow membrane module to the primary fermentor in a semi-closed loop configuration. At a cell concentration of 90g/L in the bioreactor and inlet lactose concentration of 150g/L, productivity was 240gETOH/L/hr at dilution rate of 6 hr-1. This was 80 times better than batch fermentation.

Phanerochaete chrysosporium: Growth pattern and lignin degradation

Abstract: The growth behavior of Phanerochaete chrysosporium was characterized in a bioreactor using chemostat and batch cultivation to optimize an inoculum for lignin degradation during stationary cultivation. The pattern of growth and onset of lignin degradation by cells taken from agitated conditions were compared to the behavior of cells grown under stationary conditions. Under nitrogen-limited growth conditions, the fungus displayed a continuous growth-rest-growth cycle, as visually observed and evidenced by changes in total cell carbohydrate and biomass content, indicating recycling of cell nitrogen. Cells taken from the bioreactor degraded lignin only after a mycelial mat was formed under non-agitated conditions. Formation of the mat occurred during completion of primary growth with cells taken at a dilution rate of 0.09 or 0.10 h−1 and with cells from a 1-day-old batch cultivation, resulting in an onset of lignin degradation after 2–3 days. Cells taken at dilution rates <0.09 h−1 formed the mycelial mat as a result of their secondary growth phase. The onset of this mat formation was related to the average age of the cells. Two- to four-day-old cells from the batch cultivation needed 7–9 days before they started to degrade lignin. The glucose consumption rate in the bioreactor during secondary metabolism was 0.09 g · l−1 · day−1, compared to 1.0 g · l−1 · day−1 under non-agitated conditions. This difference is discussed in reference to lignin degradation.

Fluidized‐Bed Bioreactors Using a Flocculating Strain of Zymomonas mobilis for Ethanol Production

Abstract: A recently isolated strain of Zymomonas mobilis (NRRL B-12526) has been shown to form stable floc particles that can effectively convert glucose to ethanol at rates in excess of 400 g/l/hr in a fluidized-bed bioreactor. Preliminary results indicate that such a system, yielding particles which are in the size range of 0.5 to 1mm, may have extremely high productivity, even higher than Saccharomyces cerevisiae. However, the system is so reactive that the CO/sub 2/ off-gas makes it difficult to maintain a high biomass loading in the upper part of the reactor. This lower biomass content results in a decreased ethanol productivity, which approaches 100 g/l/hr for the entire active reactor volume when over 95% of the glucose is metabolized.

Heavy metal removal in a packed-bed, anaerobic upflow (ANFLOW) bioreactor

Abstract: Etude experimentale menee sur ZnCl 2 : elimination du zinc soluble, sorption dans la biomasse et performance du reacteur en terme DCO

Ethanol production in a fluidized-bed bioreactor utilizing flocculating Zymomonas mobilis with biomass recycle

Abstract: Bench-scale, fluidized-bed bioreactor systems are being used to convert glucose to ethanol by particles of a flocculating strain of Zymomonas mobilis; ethanol production rates in excess of 600 g/l-h have been achieved. The systems have been operated successfully for extended periods (500 h) while using unsterilized feed with glucose concentrations in the range 100 to 160 g/l. The primary bioreactor was also operated in the absence of necessary nutrients but coupled to a small secondary reactor in which the biomass particles were recycled and exposed to small amounts of the nutrients. 11 references, 6 figures, 3 tables.

A bioreactor and a process for the production thereof

Abstract: A bioreactor using as carrier a glass-like gel comprising metal hydroxide compounds formed by hydrolysis of metal alkoxides and/or condensation product thereof or derivative thereof obtained by substituting a part of these hydroxy groups with fluorine atom and immobilizing enzyme or the like thereto, which improves an immobilized amount of the enzyme or the like on a weight of the carrier, and a process for production thereof.

Rapid Production of Methane with Immobilized Microbes

Abstract: Choix d'un systeme de fermentation anaerobie afin d'eviter le probleme de la fourniture de l'oxygene

Process and apparatus for the preparation of metabolic products using microorganisms

Abstract: The invention relates to a process for the preparation of metabolic products using microorganisms in aqueous medium, which is particularly suitable for biological purification of waste water, to a bioreactor (10, 14) for carrying out this process, and to a multistage biological waste-water purification plant with at least one of this type of bioreactor (10, 14). The microorganisms are exposed in the bioreactor (10, 14) to mechanical stress, which does not lead to their dispersion but significantly increases their metabolic rate. Several embodiments of bioreactors (10, 14) are indicated, in which the microorganisms are activated by supplying energy via the aqueous medium. The multistage waste-water purification plant has at least one stage with a bioreactor (10, 14) suitable for activating the microorganisms. This makes it possible greatly to reduce the residence time of the substances to be converted in the bioreactor (10, 14) and in the waste-water purification plant.

Analysis of the acetone-butanol fermentation relative to bioreactor characteristics

Abstract: The acetone-butanol fermentation was mathematically modeled, and these models used to simulate batch, single-stage continuous, and two-stage continuous fermentations. The batch process simulation results accurately reproduce trends of cell growth, acid production, and solvent production reported from experimental studies. The performance of the two-stage, continuous process was shown to be vastly superior to that of the single-stage system, based on effluent butanol concentration, volumetric productivity, and extent of substrate utilization. The performance of the two-stage system was elucidated relative to the operating parameters: ratio of reactor volumes, dilution rates, and feed carbon substrate concentration. 20 references, 5 figures, 2 tables.

Ethanol Fermentation by S. cerevisiae in a Bioreactor Packed Vertically with Ceramic Rods

Abstract: A conventional randomly packed bed reactor of immobilized cells often has several problems which reduce productivity, including plugging and channelling. A new fixed biofilm reactor has been developed to overcome these disadvantages and to increase overall productivity. Kinetic parameters, such as the saturation constant and the apparent maximum specific production rate for the fermentation of glucose, have been determined, and the ethanol tolerance has been examined. The kinetics of the fixed biofilm reactor were compared with those of the continuous stirred tank reactor.

Process Design Aspects and Comparison of Different Bioreactors

Abstract: The aim of a bioreactor is to ensure the optimal environment for the particular microorganism with respect to cell growth and/or product formation. Therefore the optimum reactor construction and operation is strongly influenced by the microorganism directly as well as indirectly due to medium properties and the biochemical process itself.