TY - JOUR A1 - Aboulnaga, E. A. A1 - Zou, H. A1 - Selmer, Thorsten A1 - Xian, M. T1 - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16 JF - Journal of Biotechnology N2 - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.jbiotec.2018.03.007 SN - 0168-1656 VL - 274 SP - 15 EP - 27 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Abulnaga, El-Hussiny A1 - Pinkenburg, Olaf A1 - Schiffels, Johannes A1 - E-Refai, Ahmed A1 - Buckel, Wolfgang A1 - Selmer, Thorsten T1 - Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli JF - Journal of bacteriology Y1 - 2013 SN - 1098-5530 [E-Journal] SN - 0021-9193 [Print] VL - 195 IS - 16 SP - 3704 EP - 3713 ER - TY - JOUR A1 - Aggarwal, P. A1 - Dhiman, S. A1 - Kumar, G. A1 - Scherer, Ulrich W. A1 - Singla, M. L. A1 - Srivastava, A. T1 - Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose JF - Indian Journal of Pure and Applied Physics N2 - Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions. Y1 - 2012 SN - 0019-5596 VL - 50 IS - 2 SP - 129 EP - 132 ER - TY - JOUR A1 - Aggarwal, Prerna A1 - Singh, Virendra A1 - Singh, Arjun A1 - Scherer, Ulrich W. A1 - Singh, Tejvir A1 - Singla, Madan L. A1 - Srivastava, Alok T1 - Physico-chemical transformations in swift heavy ion modified poly(ethyleneterephthalate) JF - Radiation Physics and Chemistry Y1 - 2011 SN - 0969-806X N1 - In Press, Accepted Manuscript SP - 1 EP - 28 PB - Pergamon Press CY - Oxford ER - TY - CHAP A1 - Al-Kaidy, H. A1 - Ulber, R. A1 - Tippkötter, Nils T1 - A platform technology for the automated reaction control in magnetizable micro-fluidic droplets T2 - Biomaterials - made in bioreactors : book of abstracts, May 26 - 28, 2014, Radisson Blu Park Hotel and Conference Dentre, Radebeul, Germany Y1 - 2014 SP - 21 EP - 22 PB - DECHEMA CY - Frankfurt am Main ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Duwe, Anna A1 - Huster, Manuel A1 - Muffler, Kai A1 - Schlegel, Christin A1 - Tim, Sieker A1 - Stadtmüller, Ralf A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Biotechnology and bioprocess engineering – from the first ullmann's article to recent trends JF - ChemBioEng Reviews N2 - For several thousand years, biotechnology and its associated technical processes have had a great impact on the development of mankind. Based on empirical methods, in particular for the production of foodstuffs and daily commodities, these disciplines have become one of the most innovative future issues. Due to the increasing detailed understanding of cellular processes, production strains can now be optimized. In combination with modern bioprocesses, a variety of bulk and fine chemicals as well as pharmaceuticals can be produced efficiently. In this article, some of the current trends in biotechnology are discussed. Y1 - 2015 U6 - http://dx.doi.org/10.1002/cben.201500008 VL - 2 IS - 3 SP - 175 EP - 184 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Kuthan, Kai A1 - Hering, Thomas A1 - Tippkötter, Nils T1 - Aqueous droplets used as enzymatic microreactors and their electromagnetic actuation JF - Journal of Visualized Experiments N2 - For the successful implementation of microfluidic reaction systems, such as PCR and electrophoresis, the movement of small liquid volumes is essential. In conventional lab-on-a-chip-platforms, solvents and samples are passed through defined microfluidic channels with complex flow control installations. The droplet actuation platform presented here is a promising alternative. With it, it is possible to move a liquid drop (microreactor) on a planar surface of a reaction platform (lab-in-a-drop). The actuation of microreactors on the hydrophobic surface of the platform is based on the use of magnetic forces acting on the outer shell of the liquid drops which is made of a thin layer of superhydrophobic magnetite particles. The hydrophobic surface of the platform is needed to avoid any contact between the liquid core and the surface to allow a smooth movement of the microreactor. On the platform, one or more microreactors with volumes of 10 µL can be positioned and moved simultaneously. The platform itself consists of a 3 x 3 matrix of electrical double coils which accommodate either neodymium or iron cores. The magnetic field gradients are automatically controlled. By variation of the magnetic field gradients, the microreactors' magnetic hydrophobic shell can be manipulated automatically to move the microreactor or open the shell reversibly. Reactions of substrates and corresponding enzymes can be initiated by merging the microreactors or bringing them into contact with surface immobilized catalysts. Y1 - 2016 U6 - http://dx.doi.org/10.3791/54643 SN - 1940-087X IS - Issue 126 ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Tippkötter, Nils T1 - Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase JF - Engineering in Life Sciences N2 - In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1–30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established. Y1 - 2016 U6 - http://dx.doi.org/10.1002/elsc.201400124 VL - 16 IS - 3 SP - 222 EP - 230 PB - Wiley-VCH CY - Weinheim ER - TY - PAT A1 - Al-Kaidy, Huschyar A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - A system and a method for the implementation of chemical, biological or physical reactions [Europäische Patentanmeldung] N2 - The invention relates to a system for the implementation of chemical, biological or physical reactions, consisting of - one or more magnetic micro-reactors, each comprising a shell made of hydrophobic magnetic nanoparticles encapsulating an aqueous core, - a plane platform comprising a surface to receive the micro-reactors, - a source that generates a magnetic field above or underneath the platform for manipulating the one or more hydrophobic magnetic micro-reactors, or for moving them along the surface of the platform from one position to another position, characterized in that the aqueous core of the one or more magnetic micro-reactors contains a reaction solution or buffer, and wherein the magnetic field generated by the source correlates to a defined position on the surface of the platform. Y1 - 2013 PB - Europäisches Patentamt CY - Den Hague ER - TY - JOUR A1 - Aletsee, Ludwig A1 - Baumann, Marcus T1 - A laboratory incubator equipped with facilities to automatically simulate natural irradiance JF - Boletim do Instituto Oceanográfico / Universidade de São Paulo Y1 - 1991 SN - 1982-436X; 0080-6331 VL - Vol. 39 IS - No. 2 SP - 155 EP - 159 ER - TY - CHAP A1 - Artmann, Gerhard A1 - Meruvu, Haritha A1 - Kizildag, Sefa A1 - Temiz Artmann, Aysegül ED - Artmann, Gerhard ED - Temiz Artmann, Aysegül ED - Zhubanova, Azhar A. ED - Digel, Ilya T1 - Functional Toxicology and Pharmacology Test of Cell Induced Mechanical Tensile Stress in 2D and 3D Tissue Cultures T2 - Biological, Physical and Technical Basics of Cell Engineering N2 - Mechanical forces/tensile stresses are critical determinants of cellular growth, differentiation and migration patterns in health and disease. The innovative “CellDrum technology” was designed for measuring mechanical tensile stress of cultured cell monolayers/thin tissue constructs routinely. These are cultivated on very thin silicone membranes in the so-called CellDrum. The cell layers adhere firmly to the membrane and thus transmit the cell forces generated. A CellDrum consists of a cylinder which is sealed from below with a 4 μm thick, biocompatible, functionalized silicone membrane. The weight of cell culture medium bulbs the membrane out downwards. Membrane indentation is measured. When cells contract due to drug action, membrane, cells and medium are lifted upwards. The induced indentation changes allow for lateral drug induced mechanical tension quantification of the micro-tissues. With hiPS-induced (human) Cardiomyocytes (CM) the CellDrum opens new perspectives of individualized cardiac drug testing. Here, monolayers of self-beating hiPS-CMs were grown in CellDrums. Rhythmic contractions of the hiPS-cells induce membrane up-and-down deflections. The recorded cycles allow for single beat amplitude, single beat duration, integration of the single beat amplitude over the beat time and frequency analysis. Dose effects of agonists and antagonists acting on Ca2+ channels were sensitively and highly reproducibly observed. Data were consistent with published reference data as far as they were available. The combination of the CellDrum technology with hiPS-Cardiomyocytes offers a fast, facile and precise system for pharmacological and toxicological studies. It allows new preclinical basic as well as applied research in pharmacolgy and toxicology. Y1 - 2018 SN - 978-981-10-7904-7 U6 - http://dx.doi.org/10.1007/978-981-10-7904-7_7 SP - 157 EP - 192 PB - Springer CY - Singapore ER - TY - BOOK A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül A1 - Zhubanova, Azhar A. A1 - Digel, Ilya ED - Artmann, Gerhard ED - Temiz Artmann, Aysegül ED - Zhubanova, Azhar A. ED - Digel, Ilya T1 - Biological, physical and technical basics of cell engineering Y1 - 2018 SN - 978-981-10-7903-0 PB - Springer CY - Singapore ER - TY - JOUR A1 - Balakrishnan, Karthikeyan A1 - Andrei-Selmer, Luminita-Cornelia A1 - Selmer, Thorsten A1 - Bacher, Michael A1 - Dodel, Richard T1 - Comparison of Intravenous Immunoglobulins for Naturally Occurring Autoantibodies against Amyloid-β JF - Journal of Alzheimer's Disease Y1 - 2010 SN - 1387-2877 VL - 20 IS - 1 SP - 135 EP - 143 ER - TY - JOUR A1 - Barbazán, Paula A1 - Hagenbach, Adelheid A1 - Paulßen, Elisabeth A1 - Abram, Ulrich A1 - Carballo, Rosa A1 - Rodriguez-Hermida, Sabina A1 - Vázquez-López, Ezequiel M. T1 - Tricarbonyl Rhenium(I) and Technetium(I) Complexes with Hydrazones Derived from 4,5-Diazafluoren-9-one and 1,10-Phenanthroline-5,6-dione JF - European Journal of Inorganic Chemistry N2 - Tricarbonylrhenium(I) and -technetium(I) halide (halide = Cl and Br) complexes of ligands derived from 4,5-diazafluoren-9-one (df) and 1,10-phenanthroline-5,6-dione (phen) derivatives of benzoic and 2-hydroxybenzoic acid hydrazides have been prepared. The complexes have been characterized by elemental analysis, MS, IR, 1H NMR and absorption and emission UV/Vis spectroscopic methods. The metal centres (ReI and TcI) are coordinated through the nitrogen imine atoms and establish five-membered chelate rings, whereas the hydrazone groups stand uncoordinated. The 1H NMR spectra suggest the same behaviour in solution on the basis of only marginal variations in the chemical shifts of the hydrazine protons. Y1 - 2010 U6 - http://dx.doi.org/10.1002/ejic.201000522 SN - 1099-0682 IS - 29 SP - 4622 EP - 4630 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Baumann, Marcus ED - Hempel, G. T1 - Primary production and phytoplankton growth in the marginal ice zone of the Fram Strait and the interpretation of the field data with autecological experiments (Abstract) T2 - Oceanography and biology of Arctic seas : selected papers from the ICES Symposium on Marine Sciences of the Arctic and Subarctic Regions, held in Santander, 28 - 30 September 1987. (Rapports et procès-verbaux des réunions / Conseil International pour l'Exploration de la Mer ; 188) Y1 - 1989 SP - 128 PB - International Council for the Exploration of the Sea CY - Copenhagen ER - TY - JOUR A1 - Baumann, Marcus A1 - Brandini, Frederico A1 - Staubes, Regina T1 - The influence of light and temperature on carbonspecific DMS release by cultures of Phaeocystis antarctica and three antarctic diatoms / Baumann, Marcus E.M. ; Brandini, Frederico ; Staubes, Regina JF - Marine Chemistry. 45 (1994), H. 1-2 Y1 - 1994 SN - 0304-4203 SP - 129 EP - 136 ER - TY - JOUR A1 - Baumann, Marcus A1 - Goeyens, L. A1 - Semeneh, M. A1 - Elskens, M. T1 - Phytoplankton nutrient utilisation and nutrient signature in the Southern Ocean / Goeyens, L. ; Semeneh, M. ; Baumann, M.E.M. ; Elskens, M. ; Shopova, D. ; Dehairs, F. JF - Journal of Marine Systems. 17 (1998), H. 1-4 Y1 - 1998 SN - 0924-7963 SP - 143 EP - 157 ER - TY - JOUR A1 - Baumann, Marcus A1 - Gradinger, R. T1 - Distribution of Phytoplankton Communities in Relation to the Large Scale Hydrographical Regime in the Fram Strait 1984 / Gradinger, R. ; Baumann, M.E.M. JF - Marine Biology. 111 (1991), H. 2 Y1 - 1991 SN - 0025-3162 SP - 311 EP - 321 ER - TY - JOUR A1 - Baumann, Marcus A1 - Hirche, H.-J. A1 - Kattner, G. A1 - Gradinger, R. T1 - Plankton distribution and the impact of copepod grazing on primary production in Fram Strait, Greenland Sea / Hirche, H.-J. ; Baumann, M.E.M. ; Kattner, G.; Gradinger, R. JF - Journal of Marine Systems. 2 (1991), H. 3-4 Y1 - 1991 SN - 0924-7963 SP - 477 EP - 494 ER - TY - JOUR A1 - Baumann, Marcus A1 - Jahnke, J. T1 - Chemical and Physical Effects on the Shape and Growth of the Diatom Biddulphia sinensis GREVILLE in Batch Cultures: A Contribution to Bioindication in Plankton Ecology / Jahnke, J. ; Baumann, M. JF - Hydrobiological Bulletin . 17 (1983), H. 1 Y1 - 1983 SN - 0165-1404 SP - 5 EP - 20 ER -