University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Biotechnology Progress

  • Publisher: Wiley
  • FAD Code: BTPR
  • CODEN: BIPRET
  • ISSN: 8756-7938
  • Abbreviation: Biotechnol. Prog.
  • DOI Prefix: 10.1002/btpr.
  • Language: English
  • Comments: Fulltext from 1985 V1. Formerly an ACS publication

Citations 9

"Growth Behavior In Plant Cell Cultures Based On Emissions Detected By A Multisensor Array"
Biotechnol. Prog. 2004 Volume 20, Issue 4 Pages 1245-1250
Palle Komaraiah, Marian Navratil, Maria Carlsson, Paul Jeffers, Maria Brodelius, Peter E. Brodelius, Patricia M. Kieran and Carl-Fredrik Mandenius

Abstract: The use of a multisensor array based on chemical gas sensors to monitor plant cell cultures is described. The multisensor array, also referred to as an electronic nose, consisted of 19 different metal oxide semiconductor sensors and one carbon dioxide sensor. The device was used to continuously monitor the off-gas from two plant cell suspension cultures, Morinda citrifolia and Nicotiana tabacum, cultivated under batch conditions. By analyzing the multiarray responses using two pattern recognition methods, principal component analysis and artificial neural networks, it was possible to monitor the course of the cultivations and, in turn, to predict (1) the biomass concentration in both systems and (2) the formation of the secondary metabolite, antraquinone, by M. citrifolia. The results identify the multisensor array method as a potentially useful analytical tool for monitoring plant process variables that are otherwise difficult to analyze on-line.

"Kalman Filter Based Glucose Control At Small Set Points During Fed-Batch Cultivation Of Saccharomyces Cerevisiae"
Biotechnol. Prog. 2004 Volume 20, Issue 1 Pages 377-383
Michael Arndt and Bernd Hitzmann

Abstract: A glucose control system is presented, which is able to control cultivations of Saccharomyces cerevisiae even at low glucose concentrations. Glucose concentrations are determined using a special flow injection analysis (FIA) system, which does not require a sampling module. An extended Kalman filter is employed for smoothing the glucose measurements as well as for the prediction of glucose and biomass concentration, the maximum specific growth rate, and the volume of the culture broth. The predicted values are utilized for feedforward/feedback control of the glucose concentration at set points of 0.08 and 0.05 g/L. The controller established well-defined conditions over several hours up to biomass concentrations of 13.5 and 20.7 g/L, respectively. The specific glucose uptake rates at both set points were 1.04 and 0.68 g/g/h, respectively. It is demonstrated that during fed-batch cultivation an overall pure oxidative metabolism of glucose is maintained at the lower set point and a specific ethanol production rate of 0.18 g/g/h at the higher set point.

"Potential Of On-Line CIMS For Bioprocess Monitoring"
Biotechnol. Prog. 2003 Volume 19, Issue 4 Pages 1355-1364
Thomas G. Custer, William P. Wagner, Shuji Kato, Veronica M. Bierbaum and Ray Fall

Abstract: Chemical-ionization mass spectrometry (CIMS) using flow reactors is an emerging method for on-line monitoring of trace concentrations of organic compounds in the gas phase. In this study, a flow-reactor CIMS instrument, employing the H3O+ cation as the ionizing reagent, was used to simultaneously monitor several volatile metabolic products as they are released into the headspace during bacterial growth in a bioreactor. Production of acetaldehyde, ethanol, acetone, butanol, acetoin, diacetyl, and isoprene by Bacillus subtilis is reported. Ion signal intensities were related to solution-phase concentrations using empirical calibrations and, in the case of isoprene, were compared with simultaneous gas chromatography measurements. Identification of volatile and semivolatile metabolites is discussed. Flow-reactor CIMS techniques should be useful for bioprocess monitoring applications because of their ability to sensitively and simultaneously monitor many volatile metabolites on-line.

"On-line Determination Of Biomass In A Microalga Bioreactor Using A Novel Computerized Flow Injection Analysis System"
Biotechnol. Prog. 2002 Volume 18, Issue 6 Pages 1387-1391
Luís A. Meireles, José L. Azevedo, João P. Cunha, and F. Xavier Malcata

Abstract: A flow injection analysis (FIA) device has been developed, which is able to assay successfully for biomass in a microalga bioreactor. The device is fully computerized and is operated via diluting small aliquots of the culture followed by measuring optical density (OD); this figure is then accurately correlated with biomass, in terms of both cell number and ash-free dry weight, during the entire culture time. Furthermore, the device is not expensive, is highly versatile, and is easy to operate owing to specifically developed, user-friendly software. The growth rate-and biomass productivity of Pavlova lutheri, cultivated under batch and semi-continuous modes, were monitored as experimental testing model.

"A Reusable And Specific Protein A-coated Piezoelectric Biosensor For Flow Injection Immunoassay"
Biotechnol. Prog. 2000 Volume 16, Issue 1 Pages 116-124
Hsin-Chun Lu, Hsiu-Mei Chen, Yu-Sheng Lin, and Jeng-Wei Lin

Abstract: A hydrophilic matrix of periodate-oxidized dextran was used as a double-sided linker to covalently immobilize Staphylococcus aureus protein A (SpA) molecules onto a poly-L-lysine-modified piezoelectric crystal surface to improve their stability, activity, and binding specificity with human immunoglobulin G (IgG) in flow injection assays. The prepared sensing crystals displayed best sensitivity and reusability at a flow rate of 140 µL/min. A human IgG concentration as low as 0.3 nM can be detected by this system. Up to 19 successive assay repetitions were achieved without significant loss of sensitivity using the same crystal. The analysis of adsorption kinetics indicates that such a preparation can greatly increase the amount of available active human IgG binding sites on immobilized SpA. Hardly any response arising from unspecific binding was detected. In addition, the sensing crystal prepared by this method was found to retain activity better than one prepared via direct deposition when stored in either wet or dry states. Finally, the prepared SpA-coated crystals were applied to the affinity immobilization of polyclonal goat anti-Schistosoma japonicum glutathione-S-transferase (GST) and were able to subsequently detect GST and its genetically engineered mutant either in a purified form or in the crude cell lysate.
Detector

"Adaptive Control At Low Glucose Concentration Of HEK-293 Cell Serum-Free Cultures"
Biotechnol. Prog. 1999 Volume 15, Issue 4 Pages 608-616
Pascal Siegwart, Johanne Côté, Keith Male, John H. T. Luong, Michel Perrier, and Amine Kamen

Abstract: Fed-batch cultures were implemented to study the metab. of HEK-293 cells. Glucose, measured every 30 min by a FIA biosensor system, was maintained at 1 mM throughout the culture using an adaptive nonlinear controller based on minimal process modeling. The controller performed satisfactorily at both low and high cell concentrations. without the need for retuning between different culture phases. Overall, lactate prodn. was significantly reduced by maintaining a low glucose concentration, thus decreasing the rate of glycolysis. The rates of glucose and glutamine uptake as well as the lactate and ammonia prodn. were compared to those obtained in batch mode with an initial glucose concentration. of 21 mM. Basically, three phases were observed in both culture modes. The metabolic shift from the first to the second phase was characterized by a significant reduction in glucose consumption and lactate prodn. while max. growth rate was maintained. The specific respiration rate appeared unchanged during the first two phases, suggesting that no change occurred in the oxidative pathway capacity. In the third phase, cell growth became slower very likely due to glutamine limitation.

"Control Of Long-term Perfusion Chinese Hamster Ovary Cell Culture By Glucose Auxostat"
Biotechnol. Prog. 1996 Volume 12, Issue 1 Pages 100-109
Konstantin B. Konstantinov, Yeong-shou Tsai, Donald Moles, and Ricaredo Matanguihan

Abstract: The strategies for control of the feed rate in high-density perfusion cultures of animal cells are limited to several simple schemes. While in an industrial environment simplicity is seen as a major advantage, the need for more elaborate closed-loop control methods that can improve process stability in long-term continuous cultures is also well understood. What has prevented the application of the advanced control strategies known from theory is the lack of reliable real-time information that can be used to close the feedback loop. Among the variables that are appropriate for direct feedback control of the perfusion rate, high priority should be given to the glucose concentration. Unlike some other environmental variables, such as dissolved oxygen and pH, it provides unambiguous information which facilitates the selection of the right feed rate. The present paper describes the application of a closed loop control scheme, known as a 'glucose-stat', to the long-term cultivation of Chinese hamster ovary cells in a high-density (35-40 million cells/mL) perfusion process. The monitoring and control system worked successfully for more than 2.5 months without any signs of performance degradation. In targeting industrial application, issues such as reliability, sterility, and accuracy, are given high priority. The implementation of the glucose monitoring system, which is the main part of the control complex, is addressed in details. The performance of the perfusion culture was evaluated at four different glucose set points, providing essential information about process optimization. It became evident that the perfusion culture was operated in the so-called 'high-gain' zone (where the system is highly sensitive to the dilution rate), which justifies the application of a feedback control. The online glucose concentration was also used by an embedded expert system which drove the process through the batch and the perfusion phase, achieving total computer control of the feed rate. In summary, the proposed glucose monitoring and control technique proved to be a reliable biotechnology tool which can be applied with confidence at an industrial scale to either microbial or mammalian cell cultures.
Glucose Fermentation broth Spectrophotometry Biotechnology Process monitoring Closed loop Optimization Perfusion

"Flow Injection Analysis Of Glucose, Fructose And Sucrose Using A Biosensor Constructed With Permeabilized Zymomonas Mobilis And Invertase"
Biotechnol. Prog. 1995 Volume 11, Issue 1 Pages 58-63
Je-Kyun Park, Min-Chol Shin, Seung-Goo Lee, and Hak-Sung Kim

Abstract: Cells of Zymomonas mobilis possessing glucose-fructose oxidoreductase and gluconolactonase were permeabilized with toluene and co-immobilized with invertase within a gelatin membrane. This membrane was coated over a pH electrode, and the resulting biosensor was placed in a flow-through cell to develop a flow injection analysis system for the specific determination of glucose, fructose, and sucrose. Peak height resulting from the production of hydrogen ion was correlated with sugar concentration, and the effect of operating variables on the response characteristics of the FIA system was investigated on the basis of theoretical and experimental analyzes. Under the optimized conditions, the calibration curves for glucose, fructose, and sucrose were linear up to 8, 80, and 60 g/L, respectively. The FIA system was applied to the online monitoring of glucose production in the enzymatic hydrolysis of cellulose, and the glucose concentrations determined using the FIA system coincided well with those determined by the conventional enzymatic method. Copyright 1995, American Chemical Society.
Glucose Fructose Sucrose Sensor Electrode Electrode Electrode Immobilized cell Optimization Method comparison

"Optimal Design Of An Enzymatic Reactor For Flow Injection Analysis"
Biotechnol. Prog. 1993 Volume 9, Issue 5 Pages 473-480
M. Poch, J. L. Montesinos, M. del Valle, J. Alonso, A. Araujo, and J. L. F. C. Lima

Abstract: A simulation procedure for the optimization of enzymatic reactors used in sandwich flow injection systems is evaluated. The system is modeled as a plug-flow reactor with axial dispersion. To calibrate it, dispersion coefficients can be evaluated using residence time distribution techniques; meanwhile, enzymatic kinetics must be determined for the system considered, according to the values of the substrate conversion attained. The model has been linked to an optimization routine based on the Powell algorithm. The proposed approach has been evaluated in a system performing simultaneous determinations of glucose and glycerol, considered the common carbon sources in a fermentation process.
Glucose Glycerol Fermentation broth Modeling Enzyme Optimization Plug flow Powell