Faseroptische Sauerstoffsensoren für Biotechnologie, Umwelt‐ und Lebensmitteltechnik

Köneke, Ralf; Comte, Andreas; Jürgens, H.; Kohls, Oliver; Lam, Hung; Scheper, Thomas

doi:10.1002/cite.330701224

Cited by 9 publications

(3 citation statements)

References 9 publications

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“…Kinetic Measurements. Catalase activities of complexes 1 (in N -methylformamide) and 3 (in acetonitrile) were measured at 25 °C on the basis of fluorescence quenching using an oxygen sensor …”

Section: Methodsmentioning

confidence: 99%

Preparation of Highly Efficient Manganese Catalase Mimics

et al. 2002

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The series of compounds [Mn(bpia)(mu-OAc)](2)(ClO(4))(2) (1), [Mn(2)(bpia)(2)(muO)(mu-OAc)](ClO(4))(3).CH(3)CN (2), [Mn(bpia)(mu-O)](2)(ClO(4))(2)(PF(6)).2CH(3)CN (3), [Mn(bpia)(Cl)(2)](ClO)(4) (4), and [(Mn(bpia)(Cl))(2)(mu-O)](ClO(4))(2).2CH(3)CN (5) (bpia = bis(picolyl)(N-methylimidazol-2-yl)amine) represents a structural, spectroscopic, and functional model system for manganese catalases. Compounds 3 and 5 have been synthesized from 2 via bulk electrolysis and ligand exchange, respectively. All complexes have been structurally characterized by X-ray crystallography and by UV-vis and EPR spectroscopies. The different bridging ligands including the rare mono-mu-oxo and mono-mu-oxo-mono-mu-carboxylato motifs lead to a variation of the Mn-Mn separation across the four binuclear compounds of 1.50 A (Mn(2)(II,II) = 4.128 A, Mn(2)(III,III) = 3.5326 and 3.2533 A, Mn(2)(III,IV) = 2.624 A). Complexes 1, 2, and 3 are mimics for the Mn(2)(II,II), the Mn(2)(III,III), and the Mn(2)(III,IV) oxidation states of the native enzyme. UV-vis spectra of these compounds show similarities to those of the corresponding oxidation states of manganese catalase from Thermus thermophilus and Lactobacillus plantarum. Compound 2 exhibits a rare example of a Jahn-Teller compression. While complexes 1 and 3 are efficient catalysts for the disproportionation of hydrogen peroxide and contain an N(4)O(2) donor set, 4 and 5 show no catalase activity. These complexes have an N(4)Cl(2) and N(4)OCl donor set, respectively, and serve as mimics for halide inhibited manganese catalases. Cyclovoltammetric data show that the substitution of oxygen donor atoms with chloride causes a shift of redox potentials to more positive values. To our knowledge, complex 1 is the most efficient binuclear functional manganese catalase mimic exhibiting saturation kinetics to date.

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Section: Methodsmentioning

confidence: 99%

Preparation of Highly Efficient Manganese Catalase Mimics

et al. 2002

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“…Kinetic Measurements: Catalase activities of all complexes were measured at 25 °C on the basis of fluorescence quenching using an oxygen sensor 42. Hydrogen peroxide solution in water was placed in a vessel equipped with a thermostat (5 mL, prepared in different concentrations from 36.6% hydrogen peroxide solution in water, concentration determined iodometrically and manganometrically).…”

Section: Methodsmentioning

confidence: 99%

Tuning the Catalase Activity of Dinuclear Manganese Complexes by Utilizing Different Substituted Tripodal Ligands

et al. 2004

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A series of five new dinuclear manganese(II/II) compounds with derivatives of 2-{[bis(pyridin-2-ylmethyl)amino]-methyl}phenol (HL 1 ) were synthesized and structurally characterized. All complexes crystallize in monoclinic space groups and exhibit Mn···Mn separations in the range of 3.392(8)−3.493(2) Å caused by bis(µ-phenoxo) bridging modes. The derivatives of HL 1 contain either electron-donating or -withdrawing substituents. A correlation between the electronic character of the different ring substituents, the

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“…The measurement principle for pO 2 is based on dynamic fluorescence quenching of molecular oxygen 3–6. The fluorescence intensity depends on the oxygen concentration in proximity to the fluorescent dye and is lowered by increasing pO 2 .…”

Section: Concepts Of Single‐use Sensorsmentioning

confidence: 99%

Process analytical sensors and image‐based techniques for single‐use bioreactors

Bluma

Höpfner

Prediger

et al. 2011

Engineering in Life Sciences

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In the field of biotechnology, the estimation of relevant process parameters is still a challenge. Particularly with regard to efficient control of processes with high product yields, a real‐time and reliable documentation with process analytical sensors is essential. Moreover, stricter regulations of the US Food and Drug Administration for the pharmaceutical industry concerning process documentation, imposed by the Process and Analytical Technology Initiative, have increased the demand for sensors that are able to very accurately monitor and document the production process. For the monitoring and control of bioprocesses, a huge variety of sensors is used. Most systems are based on optical or electrochemical sensors. Furthermore, the market demand for disposable sensor systems increases rapidly as the application of disposable bioreactors represents the biggest technical advance in modern biotechnology. These presterilized plastic bags significantly reduce the cost/income ratio and build a meaningful concept for the design and implementation of standardized peripheral bioproduction. Simple and flexible adaptation of sensors is a bottleneck and high‐production requirements of the sensor components have to be met. This contribution gives an overview on concepts of sensor systems and image‐based techniques that allow the online estimation of relevant process parameters used in single‐use bioreactor systems.

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Faseroptische Sauerstoffsensoren für Biotechnologie, Umwelt‐ und Lebensmitteltechnik

Abstract: Es wurde gezeigt, daB es moglich ist, allein anhand der 2D-Fluoreszenzdaten Aussagen uber die Biomasse (optische Dichte), das Stoffwechselverhalten (CO,) und die Eduktkon-

Cited by 9 publications

References 9 publications

Preparation of Highly Efficient Manganese Catalase Mimics

Preparation of Highly Efficient Manganese Catalase Mimics

Tuning the Catalase Activity of Dinuclear Manganese Complexes by Utilizing Different Substituted Tripodal Ligands

Process analytical sensors and image‐based techniques for single‐use bioreactors

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