Engineering in Life Sciences

Cover image for Engineering in Life Sciences

April, 2006

Volume 6, Issue 2

Pages 103–194

    1. Overview Contents: Eng. Life Sci. 2/2006 (page 103)

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200690003

    2. Contents: Eng. Life Sci. 2/2006 (pages 105–107)

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200690004

    3. Optimization and Control of Industrial Microbial Cultivation Processes (pages 117–124)

      M. Jenzsch, R. Simutis and A. Lübbert

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620901

      Compared to the immense achievements in fundamental molecular biological sciences, the improvements in the fermentation and downstream processing technologies used in industry have been less spectacular over the last decade. Hence, there is a misbalance between new cellular systems and production technologies, resulting in a decreasing annual rate of approved production processes.

    4. Oxidoreductases and Hydroxynitrilase Lyases: Complementary Enzymatic Technologies for Chiral Alcohols (pages 125–129)

      T. Daußmann, T. C. Rosen and P. Dünkelmann

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620910

      Biocatalytic processes are useful methods for the production of chiral intermediates. Alcohol dehydrogenase from Lactobacillus brevis (oxidoreductase) and (S)-oxynitrilase from Manihot esculenta (hydroxynitrile lyase) are described in detail with respect to industrial applications.

    5. Reactor Performance in the Presence of Catalyst Deactivation (pages 131–138)

      E. Flaschel

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620900

      The main variable of enzymatic processes is often found to be the operating temperature. Processes should, therefore, be optimized in order to determine the temperature which leads to a minimal demand of enzyme preparation. For the prediction of such optimal reactor operation, modeling of the temperature dependence of the process has to be performed. Examples of such modeling are given for the hydrolysis of lactose in UHT milk by means of three different β-galactosidases.

    6. Reaction Engineering Aspects of Microbial Mercury Removal (pages 139–148)

      J. Leonhäuser, M. Röhricht, I. Wagner-Döbler and W.-D. Deckwer

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620904

      Mercury-resistant microorganisms are widespread in natural environments and can effectively be used to demercurize Hg(II)-contaminated wastewaters. To find the performance limits with regard to Hg(II) loadings and residual Hg(II) at the reactor outlet and to provide a reasonable basis for an optimal and safe process design, comprehensive studies were carried out with different single microbes as well as microbial consortia.

    7. Optimization of Reaction Parameters and Cultivation Conditions for Biocatalytic Hydrogen Transfer Employing Overexpressed ADH-‘A’ from Rhodococcus ruber DSM 44541 in E. coli (pages 149–154)

      K. Edegger, C. C. Gruber, K. Faber, A. Hafner and W. Kroutil

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620902

      The alcohol dehydrogenase ADH-‘A’ from Rhodococcus ruber DSM 44541 represents a highly efficient catalyst for biocatalytic hydrogen transfer reactions. Starting from an exceedingly low level of active ADH-‘A’ in E. coli, the apparent specific activity of ADH-‘A’ overexpressed in E. coli cells could be drastically enhanced by optimizing the host and induction/growth conditions.

    8. From Enzyme Kinetics to Metabolic Network Modeling – Visualization Tool for Enhanced Kinetic Analysis of Biochemical Network Models (pages 155–162)

      M. Oldiges, S. Noack, A. Wahl, E. Qeli, B. Freisleben and W. Wiechert

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620911

      Model-based analysis of enzyme kinetics allows the determination of optimal conditions for their use in biocatalysis. Demonstrated for an Escherichia coli model of the central carbon metabolism, methods for visualization and animation of simulation data were applied and extended to facilitate model analysis and biological interpretation.

    9. Mathematical Modeling of Size Exclusion Chromatography (pages 163–169)

      B. Zelic and B. Nesek

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620903

      A mathematical model of the size exclusion chromatography (SEC) process in chromatographic columns has been developed. It considers axial dispersion in the bulk-fluid phase, interfacial film mass-transfer between the stationary and mobile phases, and diffusion of solutes within the macro pores of the packing particles. The model was validated by comparing theoretical and experimental retention times for the different columns.

    10. Electroenzymatic Synthesis of Chiral Sulfoxides (pages 170–174)

      C. Kohlmann and S. Lütz

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620907

      Chloroperoxidase from Caldariomyces fumago is able to enantioselectively oxidize various sulfides to the corresponding (R)-enantiomer of the sulfoxides. For these oxidations the enzyme requires an oxidant. Most commonly, tert-butyl hydroperoxide and hydrogen peroxide are used. As it is known that these oxidants inactivate the enzyme, the enzymatic reaction was combined with the electrochemical in situ generation of hydrogen peroxide.

    11. Comparative Study of Cyanobacteria as Biocatalysts for the Asymmetric Synthesis of Chiral Building Blocks (pages 175–179)

      J. Havel and D. Weuster-Botz

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620909

      Three representative cyanobacteria, Synechococcus PCC 7942, Anabaena variabilis, and Nostoc muscorum, were studied for their ability to asymmetrically reduce prochiral ketones. Photosynthesis as well as respiration was applied for intracellular regeneration of the NAD(P)H cofactor. It was shown for the first time that all cyanobacteria were able to reduce the prochiral ketones asymmetrically, without light for cofactor regeneration.

    12. Horseradish Peroxidase Combined With Oxidase Enzymes a Valuable Bioanalytical Tool: Lactate Oxidase – A Case Study (pages 181–186)

      V. Vojinovic, L. Bertin, J. M. S. Cabral and L. P. Fonseca

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620908

      A significant improvement of the stability of the immobilized oxidases by in situ reduction of the harmful H2O2 is reported. A lactate sensor, containing lactate oxidase aimed for bioprocess monitoring, has been described and characterized. Operational stabilities have been achieved that allow up to 8 h continuous lactate conversion with virtually no activity loss.

    13. Selective Recovery of Carbohydrates from Aqueous Solution Facilitated by a Carrier (pages 187–192)

      D. Hameister and K. Kragl

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620906

      The recovery of carbohydrates from aqueous media is a difficult separation problem due to the large, irregular and multivalent structure of carbohydrates and their low solubility in organic solvents. A method for the selective recovery of different mono- and disaccharides from aqueous media has been developed. Various organic solvents have been tested and parameters influencing the selectivity and yield of extracted carbohydrates have been studied.

    14. Easy Access to Enantiomerically Pure Nonproteinogenic Amino Acids (pages 193–194)

      K. Laumen and O. Ghisalba

      Version of Record online: 23 MAR 2006 | DOI: 10.1002/elsc.200620905

      Enantiomerically pure nonproteinogenic amino acids are of increasing interest as versatile chemical building blocks for drug discovery activities in many therapeutic indication areas. A new chemoenzymatic access with alcalase as the enantioselective biocatalyst, opens a new way for the larger-scale preparation of nonproteinogenic enantiomerically pure D- and L-α-amino acids.

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