TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Grassilage als Rohstoff für die chemische Industrie JF - Chemie Ingenieur Technik N2 - Grassilage stellt einen nachwachsenden Rohstoff mit großem Potenzial dar. Neben Cellulose und Hemicellulose enthält sie auch organische Säuren, insbesondere Milchsäure. In einem Bioraffinerie-Projekt wird die Milchsäure aus der Silage isoliert und mit gentechnisch optimierten Stämmen zu L-Lysin weiterverarbeitet. Die Lignocellulose wird hydrolysiert und zu Ethanol fermentiert. Ein besonderes Augenmerk liegt auf der Integration der unterschiedlichen Prozesse sowie der einzelnen Prozessschritte zu einem Gesamtprozess, der sämtliche Inhaltsstoffe der Silage verwertet. Y1 - 2010 U6 - https://doi.org/10.1002/cite.201000088 SN - 1522-2640 VL - 82 IS - 8, Special Issue: Industrielle Nutzung nachwachsender Rohstoffe SP - 1153 EP - 1159 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development JF - Engineering in Life Sciences N2 - Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step. Y1 - 2011 U6 - https://doi.org/10.1002/elsc.201000160 N1 - Special Issue "Bioprocess‐oriented plant design" VL - 11 IS - 4 SP - 436 EP - 442 PB - Wiley CY - Weinheim ER - TY - GEN A1 - Tippkötter, Nils A1 - Sieker, T. A1 - Wiesen, S. A1 - Duwe, A. A1 - Roth, J. A1 - Ulber, Roland T1 - Simultane Saccharifizierung und Fermentierung (SSF) sowie Produktion von Aceton, Butanol, Ethanol (ABE) und Dicarbonsäuren aus technischer Cellulose T2 - Chemie Ingenieur Technik N2 - Technische Cellulose wurde als möglicher Rohstoff zur fermentativen Produktbildung untersucht. Hierfür wird Cellulose in der Lignocellulose-Bioraffinerie hergestellt und daraus Hydrolysat gewonnen. Die Prüfung der technischen Hydrolysate als Substrate erfolgte anhand eines breiten Spektrums an Bioprodukten, von Kraftstoffen wie Ethanolund Butanol, bis zu den Dicarbonsäuren Itacon- und Bernsteinsäure. Dabei werden Bakterien, Hefen und Pilze als Produktionsorganismen eingesetzt. Die einzelnen Herstellverfahren stellen unterschiedliche Anforderungen an die Substrathandhabung. Im Fall der Ethanol- und Butanol-Gewinnung kann eine simultane Saccharifizierung und Fermentierung (SSF) durchgeführt werden. Aufgrund der Produkttoxizität erfordert die Butanol-Herstellung dabei eine In-situ-Produktabtrennung durch Lösemittelimprägnierte Partikel. Die Herstellung der beiden Dicarbonsäuren unterscheidet sich in der Sensitivität der verwendeten Mikroorganismen gegenüber Inhibitoren, die in Spuren im Hydrolysat enthalten sind. Die Bernteinsäurebildung mit Actinobacillussuccinogenes kann mit unbehandeltem Hydrolysat erfolgen. Dagegen erfordert die Gewinnung von Itaconsäure mit A. terreus eine Detoxifizierung des Hydrolysats. Insgesamt konnte gezeigt werden, dass sämtliche Bioraffinerie-Hydrolysate als Substrate für unterschiedliche Fermentationen geeignet sind. Y1 - 2014 U6 - https://doi.org/10.1002/cite.201450297 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung 2014 und 31. DECHEMA-Jahrestagung der Biotechnologen, 30. September - 2. Oktober 2014, Eurogress Aachen VL - 86 IS - 9 SP - 1518 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Handtke, Stefan A1 - Schroeter, Rebecca A1 - Jürgen, Britta A1 - Methling, Karen A1 - Schlüter, Rabea A1 - Albrecht, Dirk A1 - Hijum, Sacha A. F. T. van A1 - Bongaerts, Johannes A1 - Maurer, Karl-Heinz A1 - Lalk, Michael A1 - Schweder, Thomas A1 - Hecker, Michael A1 - Voigt, Birgit T1 - Bacillus pumilus reveals a remarkably high resistance to hydrogen peroxide provoked oxidative stress JF - PLOS one N2 - Bacillus pumilus is characterized by a higher oxidative stress resistance than other comparable industrially relevant Bacilli such as B. subtilis or B. licheniformis. In this study the response of B. pumilus to oxidative stress was investigated during a treatment with high concentrations of hydrogen peroxide at the proteome, transcriptome and metabolome level. Genes/proteins belonging to regulons, which are known to have important functions in the oxidative stress response of other organisms, were found to be upregulated, such as the Fur, Spx, SOS or CtsR regulon. Strikingly, parts of the fundamental PerR regulon responding to peroxide stress in B. subtilis are not encoded in the B. pumilus genome. Thus, B. pumilus misses the catalase KatA, the DNA-protection protein MrgA or the alkyl hydroperoxide reductase AhpCF. Data of this study suggests that the catalase KatX2 takes over the function of the missing KatA in the oxidative stress response of B. pumilus. The genome-wide expression analysis revealed an induction of bacillithiol (Cys-GlcN-malate, BSH) relevant genes. An analysis of the intracellular metabolites detected high intracellular levels of this protective metabolite, which indicates the importance of bacillithiol in the peroxide stress resistance of B. pumilus. Y1 - 2014 U6 - https://doi.org/10.1371/journal.pone.0085625 SN - 1932-6203 VL - 9 IS - 1 PB - PLOS CY - San Francisco ER - TY - GEN A1 - Graf, Alain-Michel A1 - Steinhof, Rafael A1 - Lotz, Martin A1 - Tippkötter, Nils A1 - Kasper, Cornelia A1 - Beutel, Sascha A1 - Ulber, Roland T1 - Downstream-Processing mit Membranadsorbern zur Isolierung nativer Proteinfraktionen aus Kartoffelfruchtwasser T2 - Chemie Ingenieur Technik N2 - Bei der Stärkeproduktion entstehendes Kartoffelfruchtwasser besitzt mit 2 – 3 % einen hohen Anteil an ernährungsphysiologisch interessanten Proteinen. Die industrielle Gewinnung dieser Proteinfracht liefert jedoch lediglich ein minderwertiges, denaturiertes Produkt. Mit Hilfe der Membranadsorber-Technologie lassen sich aus Kartoffelfruchtwasser unter milden Reaktionsbedingungen native bioaktive Proteinfraktionen gewinnen. Geeignete Trennbedingungen wurden im Labormaßstab entwickelt und in den Technikumsmaßstab übertragen. An Anionenaustauscher-Membranadsorbern mit einer Membranfläche von 10 000 cm2 wurde eine Patatinhaltige Fraktion (44 kDa) mit Bindungskapazitäten von 0,37 mg/cm2 isoliert. Eine niedermolekulare Proteinfraktion mit Protease-Inhibitoren konnte durch Kationenaustauscher-Membranadsorber mit Bindungskapazitäten von 1,00 mg/cm2 gewonnen werden. Sie ist für verschiedenste Applikationen in der pharmazeutischen, kosmetischen und der Nahrungsmittelindustrie interessant z. B. für Appetitzügler oder muskelaufbauende Proteinpräparate. Der Aufreinigung der nativen Proteinfraktionen durch Ultra-/Diafiltration schließt sich die Konfektionierung durch Sprühtrocknung an. Die bioanalytische Charakterisierung der Produkte belegt die Reinheit und die enzymatische Aktivität sowie die Abreicherung von Störkomponenten wie Glykoalkaloide und Polyphenoloxidasen. Y1 - 2009 U6 - https://doi.org/10.1002/cite.200800139 VL - 81 IS - 3 SP - 267 EP - 274 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Kappler-Tanudyaya, Nathalie A1 - Schmitt, Heike A1 - Tippkötter, Nils A1 - Meyer, Lina A1 - Lenzen, Sigurd A1 - Ulber, Roland T1 - Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose JF - Biotechnology Journal N2 - Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently. Y1 - 2007 U6 - https://doi.org/10.1002/biot.200700004 SN - 1860-7314 VL - 2 IS - 6 SP - 692 EP - 699 ER - TY - JOUR A1 - Muschallik, Lukas A1 - Kipp, Carina Ronja A1 - Recker, Inga A1 - Bongaerts, Johannes A1 - Pohl, Martina A1 - Gelissen, Melanie A1 - Schöning, Michael Josef A1 - Selmer, Thorsten A1 - Siegert, Petra T1 - Synthesis of α-hydroxy ketones and vicinal diols with the Bacillus licheniformis DSM 13T butane-2, 3-diol dehydrogenase JF - Journal of Biotechnology N2 - The enantioselective synthesis of α-hydroxy ketones and vicinal diols is an intriguing field because of the broad applicability of these molecules. Although, butandiol dehydrogenases are known to play a key role in the production of 2,3-butandiol, their potential as biocatalysts is still not well studied. Here, we investigate the biocatalytic properties of the meso-butanediol dehydrogenase from Bacillus licheniformis DSM 13T (BlBDH). The encoding gene was cloned with an N-terminal StrepII-tag and recombinantly overexpressed in E. coli. BlBDH is highly active towards several non-physiological diketones and α-hydroxyketones with varying aliphatic chain lengths or even containing phenyl moieties. By adjusting the reaction parameters in biotransformations the formation of either the α-hydroxyketone intermediate or the diol can be controlled. Y1 - 2020 SN - 2590-1559 U6 - https://doi.org/10.1016/j.jbiotec.2020.09.016 VL - 202 IS - Vol. 324 SP - 61 EP - 70 PB - Elsevier CY - Amsterdam 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 - Krämer, Marco A1 - Bongaerts, Johannes A1 - Bovenberg, Roel A1 - Kremer, Susanne A1 - Müller, Ulrike A1 - Orf, Sonja A1 - Wubbolts, Marcel A1 - Raeven, Leon T1 - Metabolic engineering for microbial production of shikimic acid JF - Metabolic engineering Y1 - 2003 SN - 1096-7184 (E-Journal); 1096-7176 (Print) VL - Vol. 5 IS - Iss. 4 SP - 277 EP - 283 ER - TY - JOUR A1 - Capitain, Charlotte A1 - Ross-Jones, Jesse A1 - Möhring, Sophie A1 - Tippkötter, Nils T1 - Differential scanning calorimetry for quantification of polymer biodegradability in compost JF - International Biodeterioration & Biodegradation N2 - The objective of this study is the establishment of a differential scanning calorimetry (DSC) based method for online analysis of the biodegradation of polymers in complex environments. Structural changes during biodegradation, such as an increase in brittleness or crystallinity, can be detected by carefully observing characteristic changes in DSC profiles. Until now, DSC profiles have not been used to draw quantitative conclusions about biodegradation. A new method is presented for quantifying the biodegradation using DSC data, whereby the results were validated using two reference methods. The proposed method is applied to evaluate the biodegradation of three polymeric biomaterials: polyhydroxybutyrate (PHB), cellulose acetate (CA) and Organosolv lignin. The method is suitable for the precise quantification of the biodegradability of PHB. For CA and lignin, conclusions regarding their biodegradation can be drawn with lower resolutions. The proposed method is also able to quantify the biodegradation of blends or composite materials, which differentiates it from commonly used degradation detection methods. Y1 - 2020 U6 - https://doi.org/10.1016/j.ibiod.2020.104914 SN - 0964-8305 VL - 149 SP - In Press, Article number 104914 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roikaew, N. A1 - Ulber, Roland T1 - Nitratentfernung aus Molkekonzentrat mit biotechnologischer Regeneration der Abwässer JF - Deutsche Milchwirtschaft Y1 - 2007 SN - 0012-0480 VL - 58 IS - 15 SP - 540 EP - 542 ER - TY - JOUR A1 - Engel, Mareike A1 - Holtmann, Dirk A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Increased Biobutanol Production by Mediator‐Less Electro‐Fermentation JF - Biotechnology Journal N2 - A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at −600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6% compared to 23.3% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry. Y1 - 2018 U6 - https://doi.org/10.1002/biot.201800514 SN - 1860-7314 VL - 14 IS - 4 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Engel, Mareike A1 - Gemünde, Andre A1 - Holtmann, Dirk A1 - Müller-Renno, Christine A1 - Ziegler, Christiane A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Clostridium acetobutylicum’s connecting world: cell appendage formation in bioelectrochemical systems JF - ChemElectroChem N2 - Bacterial cell appendix formation supports cell-cell interaction, cell adhesion and cell movement. Additionally, in bioelectrochemical systems (BES), cell appendages have been shown to participate in extracellular electron transfer. In this work, the cell appendix formation of Clostridium acetobutylicum in biofilms of a BES are imaged and compared with conventional biofilms. Under all observed conditions, the cells possess filamentous appendages with a higher number and density in the BES. Differences in the amount of extracellular polymeric substance in the biofilms of the electrodes lead to the conclusion that the cathode can be used as electron donor and the anode as electron acceptor by C. acetobutylicum. When using conductive atomic force microscopy, a current response of about 15 nA is found for the cell appendages from the BES. This is the first report of conductivity for clostridial cell appendices and represents the basis for further studies on their role for biofilm formation and electron transfer. Y1 - 2019 U6 - https://doi.org/10.1002/celc.201901656 SN - 2196-0216 VL - 7 IS - 2 SP - 414 EP - 420 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roikaew, Wipa A1 - Ulber, Roland A1 - Hoffmann, Alexander A1 - Denzler, Hans-Jörg A1 - Buchholz, Heinrich T1 - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food JF - Biotechnology Progress N2 - Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. Y1 - 2010 U6 - https://doi.org/10.1002/btpr.384 SN - 8756-7938 VL - 26 IS - 3 SP - 756 EP - 762 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Voigt, Birgit A1 - Albrecht, Dirk A1 - Sievers, Susanne A1 - Becher, Dörte A1 - Bongaerts, Johannes A1 - Evers, Stefan A1 - Schweder, Thomas A1 - Maurer, Karl-Heinz A1 - Hecker, Michael T1 - High-resolution proteome maps of Bacillus licheniformis cells growing in minimal medium JF - Proteomics Y1 - 2015 U6 - https://doi.org/10.1002/pmic.201400504 SN - 1615-9861 VL - 15 IS - 15 SP - 2629 EP - 2633 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Duwe, A. A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Lignocellulose-Biorefinery: Ethanol-Focused T2 - Biorefineries N2 - The development prospects of the world markets for petroleum and other liquid fuels are diverse and partly contradictory. However, comprehensive changes for the energy supply of the future are essential. Notwithstanding the fact that there are still very large deposits of energy resources from a geological point of view, the finite nature of conventional oil reserves is indisputable. To reduce our dependence on oil, the EU, the USA, and other major economic zones rely on energy diversification. For this purpose, alternative materials and technologies are being sought, and is most obvious in the transport sector. The objective is to progressively replace fossil fuels with renewable and more sustainable fuels. In this respect, biofuels have a pre-eminent position in terms of their capability of blending with fossil fuels and being usable in existing cars without substantial modification. Ethanol can be considered as the primary renewable liquid fuel. In this chapter enzymes, micro-organisms, and processes for ethanol production based on renewable resources are described. KW - Bioethanol KW - Biorefinery KW - Lignocellulose feedstook Y1 - 2018 U6 - https://doi.org/10.1007/10_2016_72 N1 - Part of the Advances in Biochemical Engineering/Biotechnology book series (ABE,volume 166) SP - 177 EP - 215 PB - Springer CY - Cham ER - TY - JOUR A1 - Hoffstadt, Kevin A1 - Nikolausz, Marcell A1 - Krafft, Simone A1 - Bonatelli, Maria A1 - Kumar, Vivekanantha A1 - Harms, Hauke A1 - Kuperjans, Isabel T1 - Optimization of the ex situ biomethanation of hydrogen and carbon dioxide in a novel meandering plug flow reactor: start-up phase and flexible operation JF - Bioengineering KW - methanation KW - plug flow reactor KW - bubble column KW - biomethane KW - P2G Y1 - 2024 U6 - https://doi.org/10.3390/bioengineering11020165 SN - 2306-5354 VL - 11 IS - 2 PB - MDPI CY - Basel ER - TY - CHAP A1 - Wulfhorst, H. A1 - Duwe, A. A1 - Möhring, S. A1 - Jurca, O. A1 - Tippkötter, Nils T1 - Analysis of pretreated biomass by differential scanning 132 calorimetry and multivariate data analysis T2 - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany Y1 - 2016 SP - 132 PB - DECHEMA CY - Frankfurt am Main ER - TY - JOUR A1 - Sieker, Tim A1 - Ulber, Roland A1 - Dimitrova, Darina A1 - Bart, Hans-Jörg A1 - Neuner, Andreas A1 - Heinzle, Elmar A1 - Tippkötter, Nils T1 - Silage : Fermentationsrohstoff für die chemische Industrie? JF - labor&more N2 - In Anbetracht des zu erwartenden Rückgangs der Verfügbarkeit fossiler Rohstoffe müssen nicht nur für den Energiesektor, sondern auch für die Herstellung industrieller Produkte alternative Rohstoffe gefunden werden. Ein Beispiel für einen nicht in Nahrungsmittelkonkurrenz stehenden nachwachsenden Rohstoff ist grüne Biomasse wie Gras und Klee. Diese lassen sich in Deutschland auf großen Flächen anbauen und enthalten eine Vielzahl potenzieller Substrate für Fermentationen. Y1 - 2009 IS - 2 SP - 44 EP - 45 ER - TY - PAT A1 - Stadtmüller, Ralf A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Method for production of single-stranded macronucleotides N2 - The invention relates to a method for production of single-stranded macronucleotides by amplifying and ligating an extended monomeric single-stranded target nucleic acid sequence (targetss) into a repetitive cluster of double-stranded target nucleic acid sequences (targetds), and subsequently cloning the construct into a vector (aptagene vector). The aptagene vector is transformed into host cells for replication of the aptagene and isolated in order to optain single-stranded target sequences (targetss). The invention also relates to single-stranded nucleic acids, produced by a method of the invention. Y1 - 2015 N1 - Patent auch unter EP2774996, EP2774996, US2017145460 und US9944966 veröffentlicht. ER - TY - JOUR A1 - Gerigk, M. A1 - Maaß, D. A1 - Kreutzer, A. A1 - Sprenger, G. A1 - Bongaerts, Johannes A1 - Wubbolts, Marcel A1 - Takors, Ralf T1 - Enhanced pilot-scale fed-batch L-phenylalanine production with recombinant Escherichia coli by fully integrated reactive extraction JF - Bioprocess and biosystems engineering Y1 - 2002 SN - 1432-0797 (E-Journal); 1615-7605 (E-Journal); 0178-515X (Print); 1615-7591 (Print) VL - Vol. 25 IS - Iss. 1 SP - 43 EP - 52 ER - TY - JOUR A1 - Tippkötter, Nils A1 - Stückmann, Henning A1 - Kroll, Stephen A1 - Winkelmann, Gunda A1 - Noack, Udo A1 - Scheper, Thomas A1 - Ulber, Roland T1 - A semi-quantitative dipstick assay for microcystin JF - Analytical and Bioanalytical Chemistry N2 - An immunochromatographic lateral flow dipstick assay for the fast detection of microcystin-LR was developed. Colloid gold particles with diameters of 40 nm were used as red-colored antibody labels for the visual detection of the antigen. The new dipstick sensor is capable of detecting down to 5 µg·l−1 (ppb; total inversion of the color signal) or 1 ppb (observation of color grading) of microcystin-LR. The course of the labeling reaction was observed via spectrometric wave shifts caused by the change of particle size during the binding of antibodies. Different stabilizing reagents showed that especially bovine serum albumin (BSA) and casein increase the assays sensitivity and the conjugate stability. Performance of the dipsticks was quantified by pattern processing of capture zone CCD images. Storage stability of dipsticks and conjugate suspensions over 115 days under different conditions were monitored. The ready-to-use dipsticks were successfully tested with microcystin-LR-spiked samples of outdoor drinking- and salt water and applied to the tissue of microcystin-fed mussels. Y1 - 2009 U6 - https://doi.org/10.1007/s00216-009-2750-8 SN - 1618-2650 VL - 394 IS - 3 SP - 863 EP - 869 PB - springer CY - Berlin ER - TY - JOUR A1 - Muschallik, Lukas A1 - Molinnus, Denise A1 - Jablonski, Melanie A1 - Kipp, Carina Ronja A1 - Bongaerts, Johannes A1 - Pohl, Martina A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Selmer, Thorsten A1 - Siegert, Petra T1 - Synthesis of α-hydroxy ketones and vicinal (R, R)-diols by Bacillus clausii DSM 8716ᵀ butanediol dehydrogenase JF - RSC Advances N2 - α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the R-selective 2,3-butanediol dehydrogenase from B. clausii DSM 8716ᵀ (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed. In addition, surprisingly alkyl phenyl dicarbonyls, like 2-hydroxy-1-phenylpropan-1-one and phenylglyoxal are accepted, whereas their derivatives with two phenyl groups are not substrates. Supplementation of Mn²⁺ (1 mM) increases BcBDH's activity in biotransformations. Furthermore, the biocatalytic reduction of 5-methyl-2,3-hexanedione to mainly 5-methyl-3-hydroxy-2-hexanone with only small amounts of 5-methyl-2-hydroxy-3-hexanone within an enzyme membrane reactor is demonstrated. Y1 - 2020 U6 - https://doi.org/10.1039/D0RA02066D SN - 2046-2069 VL - 10 SP - 12206 EP - 12216 PB - Royal Society of Chemistry (RSC) CY - Cambridge ER - TY - JOUR A1 - Küppers, Tobias A1 - Steffen, Victoria A1 - Hellmuth, Hendrik A1 - O'Connell, Timothy A1 - Bongaerts, Johannes A1 - Maurer, Karl-Heinz A1 - Wiechert, Wolfgang T1 - Developing a new production host from a blueprint: Bacillus pumilus as an industrial enzyme producer JF - Microbial cell factories Y1 - 2014 U6 - https://doi.org/10.1186/1475-2859-13-46 SN - 1475-2859 (E-Journal) VL - 13 SP - Article No. 46 PB - BioMed Central CY - London ER - TY - CHAP A1 - Möhring, S. A1 - Wulfhorst, H. A1 - Roth, J. A1 - Tippkötter, Nils T1 - Pretreatment strategies for lignocellulosic biomass T2 - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany Y1 - 2016 SP - 131 PB - DECHEMA CY - Frankfurt am Main ER - TY - CHAP A1 - Roth, J. A1 - Möhring, S. A1 - Tippkötter, Nils T1 - Characterization and evaluation of lignocellulosic biomass 130 hydrolysates for ABE fermentation T2 - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany Y1 - 2016 SP - 130 PB - DECHEMA CY - Frankfurt am Main 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 - https://doi.org/10.3791/54643 SN - 1940-087X IS - Issue 126 ER - TY - JOUR A1 - Heinze, D. A1 - Mang, Thomas A1 - Popescu, C. A1 - Weichold, O. T1 - Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers JF - Thermochimica Acta N2 - Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃–(CH₂CH (OCO(CH₂)ₘCH₃))ₙ–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain. Y1 - 2016 U6 - https://doi.org/10.1016/j.tca.2016.05.015 SN - 0040-6031 (electronic) VL - 637 SP - 143 EP - 153 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pinkenburg, Olaf A1 - Schiffels, Johannes A1 - Selmer, Thorsten T1 - Das CoLibry-Konzept – ein Werkzeugkasten für die Synthetische Biologie: Bioproduktion JF - BIOspektrum N2 - Regardless of size or destination, synthetic biology starts with com-parably small information units, which need to be combined and properly arranged in order to achieve a certain goal. This may be the de novo synthesis of individual genes from oligonucleotides, a shuffling of protein domains in order to create novel biocatalysts, the assembly of multiple enzyme encoding genes in metabolic pathway design, or strain development at the production stage. The CoLibry concept has been designed in order to close the gap between recombinant production of individual genes and genome editing. Y1 - 2016 U6 - https://doi.org/10.1007/s12268-016-0734-8 VL - 22 IS - 6 SP - 593 EP - 595 PB - Springer CY - Berlin ER - TY - JOUR A1 - Ghosch, S. A1 - Baier, M. A1 - Schütz, J. A1 - Schneider, Felix A1 - Scherer, Ulrich W. T1 - Analysis of electronic autoradiographs by mathematical post-processing JF - Radiation Effects and Defects in Solids: Incorporating plasma science and plasma technology N2 - Autoradiography is a well-established method of nuclear imaging. When different radionuclides are present simultaneously, additional processing is needed to distinguish distributions of radionuclides. In this work, a method is presented where aluminium absorbers of different thickness are used to produce images with different cut-off energies. By subtracting images pixel-by-pixel one can generate images representing certain ranges of β-particle energies. The method is applied to the measurement of irradiated reactor graphite samples containing several radionuclides to determine the spatial distribution of these radionuclides within pre-defined energy windows. The process was repeated under fixed parameters after thermal treatment of the samples. The greyscale images of the distribution after treatment were subtracted from the corresponding pre-treatment images. Significant changes in the intensity and distribution of radionuclides could be observed in some samples. Due to the thermal treatment parameters the most significant differences were observed in the ³H and ¹⁴C inventory and distribution. Y1 - 2016 U6 - https://doi.org/10.1080/10420150.2016.1155587 SN - 1029-4953 VL - 171 IS - 1-2 SP - 161 EP - 172 PB - Taylor & Francis CY - London ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie, 5: Elektrochemie Y1 - 2016 SN - 978-3-662-47559-1 PB - Springer CY - Berlin ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie, 4: Reaktionskinetik Y1 - 2016 SN - 978-3-662-47674-1 PB - Springer CY - Berlin ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie, 3: Phasengleichgewichte Y1 - 2016 SN - 978-3-662-47571-3 PB - Springer CY - Berlin ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie, 2: Chemische Thermodynamik Y1 - 2016 SN - 978-3-662-47621-5 PB - Springer CY - Berlin ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie, 1: Grundlagen der Thermodynamik und Verhalten der Gase Y1 - 2016 SN - 978-3-662-47676-5 PB - Springer CY - Berlin ER - TY - BOOK A1 - Lauth, Jakob A1 - Kowalczyk, Jürgen T1 - Einführung in die Physik und Chemie der Grenzflächen und Kolloide Y1 - 2016 SN - 978-3-662-47018-3 U6 - https://doi.org/10.1007/978-3-662-47018-3 PB - Springer CY - Berlin ER - TY - BOOK A1 - Feuerriegel, Uwe T1 - Verfahrenstechnik mit EXCEL: Verfahrenstechnische Berechnungen effektiv durchführen und professionell dokumentieren Y1 - 2016 SN - 978-3-658-02902-9 U6 - https://doi.org/10.1007/978-3-658-02903-6 N1 - 152 Abbildungen, 94 Abbildungen in Farbe Gedruckt in der Bibliothek unter der Signatur: 21 ZNK 11 PB - Springer Fachmedien CY - Wiesbaden ER - 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 - https://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 - Druckenmüller, Katharina A1 - Günther, Klaus A1 - Elbers, Gereon T1 - Near-infrared spectroscopy (NIRS) as a tool to monitor exhaust air from poultry operations JF - Science of the Total Environment N2 - Intensive poultry operation systems emit a considerable volume of inorganic and organic matter in the surrounding environment. Monitoring cleaning properties of exhaust air cleaning systems and to detect small but significant changes in emission characteristics during a fattening cycle is important for both emission and fattening process control. In the present study, we evaluated the potential of near-infrared spectroscopy (NIRS) combined with chemometric techniques as a monitoring tool of exhaust air from poultry operation systems. To generate a high-quality data set for evaluation, the exhaust air of two poultry houses was sampled by applying state-of-the-art filter sampling protocols. The two stables were identical except for one crucial difference, the presence or absence of an exhaust air cleaning system. In total, twenty-one exhaust air samples were collected at the two sites to monitor spectral differences caused by the cleaning device, and to follow changes in exhaust air characteristics during a fattening period. The total dust load was analyzed by gravimetric determination and included as a response variable in multivariate data analysis. The filter samples were directly measured with NIR spectroscopy. Principal component analysis (PCA), linear discriminant analysis (LDA), and factor analysis (FA) were effective in classifying the NIR exhaust air spectra according to fattening day and origin. The results indicate that the dust load and the composition of exhaust air (inorganic or organic matter) substantially influence the NIR spectral patterns. In conclusion, NIR spectroscopy as a tool is a promising and very rapid way to detect differences between exhaust air samples based on still not clearly defined circumstances triggered during a fattening period and the availability of an exhaust air cleaning system. Y1 - 2018 U6 - https://doi.org/10.1016/j.scitotenv.2018.02.072 SN - 0048-9697 VL - 630 SP - 536 EP - 543 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Temiz Artmann, Aysegül T1 - Sicanlarda, akut egzersiz sonucu gelisen oksidan stresin lökosit aktivasyon degisiklikleri ile ile olan iliskisi ve eritrosit deformabilitesine etkisi T1 - The oxidative stress effect on leukocyte activation and erythrocyte deformability after acute exercise in rats Y1 - 1996 N1 - Dokuz Eylül Üniversitesi, Izmir, Diss., 1996. Veröffentlicht unter Temiz, Ayşegül ER - TY - THES A1 - Temiz Artmann, Aysegül T1 - Sicanlarda egzersiz sonrasi oksidatif hasar ve eritrosit membran degisikliklerinin hemoreolojik etkileri T1 - The effect of oxidative stress and erythrocyte membrane changes on hemorheological factors following exercise in rats Y1 - 2001 N1 - Dokuz Eylül Üniversitesi, Izmir, Diss., 2001. Veröffentlicht unter Temiz, Aysegül ER - TY - JOUR A1 - Pilas, Johanna A1 - Yazici, Y. A1 - Selmer, Thorsten A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Application of a portable multi-analyte biosensor for organic acid determination in silage JF - Sensors N2 - Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media. Y1 - 2018 U6 - https://doi.org/10.3390/s18051470 SN - 1424-8220 VL - 18 IS - 5 PB - MDPI CY - Basel ER - TY - CHAP A1 - Kazuki, Yasuhiro A1 - Kobayashi, Kaoru A1 - Hirabayashi, Masumi A1 - Abe, Satoshi A1 - Kajitani, Naoyo A1 - Kazuki, Kanoko A1 - Takehara, Shoko A1 - Takiguchi, Masato A1 - Satoh, Daisuke A1 - Kuze, Jiro A1 - Sakuma, Tetsushi A1 - Kaneko, Takehito A1 - Mashimo, Tomoji A1 - Osamura, Minori A1 - Hashimoto, Mari A1 - Wakatsuki, Riko A1 - Hirashima, Rika A1 - Fujiwara, Ryoichi A1 - Deguchi, Tsuneo A1 - Kurihara, Atsushi A1 - Tsukazaki, Yasuko A1 - Senda, Naoto A1 - Yamamoto, Takashi A1 - Scheer, Nico A1 - Oshimura, Mitsuo T1 - Humanized UGT2 and CYP3A transchromosomic rats for improved prediction of human drug metabolism T2 - PNAS Proceedings of the National Academy of Sciences of the United States of America Y1 - 2019 U6 - https://doi.org/10.1073/pnas.1808255116 SN - 1091-6490 VL - 116 IS - 8 SP - 3072 EP - 3081 ER - TY - JOUR A1 - Wilson, C. E. A1 - Dickie, A. P. A1 - Schreiter, K. A1 - Wehr, R. A1 - Wilson, E. M. A1 - Bial, J. A1 - Scheer, Nico A1 - Wilson, I. D. A1 - Riley, R. J. T1 - The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice JF - Archives of Toxicology N2 - The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans. Y1 - 2018 U6 - https://doi.org/10.1007/s00204-018-2212-1 SN - 1432-0738 VL - 92 IS - 6 SP - 1953 EP - 1967 PB - Springer ER - TY - JOUR A1 - Ross, Jillian A1 - Plummer, Simon M. A1 - Rode, Anja A1 - Scheer, Nico A1 - Bower, Conrad C. A1 - Vogel, Ortwin A1 - Henderson, Colin J. A1 - Wolf, C. Roland A1 - Elcombe, Clifford R. T1 - Human constitutive androstane receptor (CAR) and pregnane X receptor (PXR) support the hypertrophic but not the hyperplastic response to the murine nongenotoxic hepatocarcinogens phenobarbital and chlordane in vivo JF - Toxicological Sciences N2 - Mouse nongenotoxic hepatocarcinogens phenobarbital (PB) and chlordane induce hepatomegaly characterized by hypertrophy and hyperplasia. Increased cell proliferation is implicated in the mechanism of tumor induction. The relevance of these tumors to human health is unclear. The xenoreceptors, constitutive androstane receptors (CARs), and pregnane X receptor (PXR) play key roles in these processes. Novel “humanized” and knockout models for both receptors were developed to investigate potential species differences in hepatomegaly. The effects of PB (80 mg/kg/4 days) and chlordane (10 mg/kg/4 days) were investigated in double humanized PXR and CAR (huPXR/huCAR), double knockout PXR and CAR (PXRKO/CARKO), and wild-type (WT) C57BL/6J mice. In WT mice, both compounds caused increased liver weight, hepatocellular hypertrophy, and cell proliferation. Both compounds caused alterations to a number of cell cycle genes consistent with induction of cell proliferation in WT mice. However, these gene expression changes did not occur in PXRKO/CARKO or huPXR/huCAR mice. Liver hypertrophy without hyperplasia was demonstrated in the huPXR/huCAR animals in response to both compounds. Induction of the CAR and PXR target genes, Cyp2b10 and Cyp3a11, was observed in both WT and huPXR/huCAR mouse lines following treatment with PB or chlordane. In the PXRKO/CARKO mice, neither liver growth nor induction of Cyp2b10 and Cyp3a11 was seen following PB or chlordane treatment, indicating that these effects are CAR/PXR dependent. These data suggest that the human receptors are able to support the chemically induced hypertrophic responses but not the hyperplastic (cell proliferation) responses. At this time, we cannot be certain that hCAR and hPXR when expressed in the mouse can function exactly as the genes do when they are expressed in human cells. However, all parameters investigated to date suggest that much of their functionality is maintained. Y1 - 2010 U6 - https://doi.org/10.1093/toxsci/kfq118 SN - 1096-0929 VL - 116 IS - 2 SP - 452 EP - 466 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Scheer, Nico A1 - Ross, Jillian A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Wolf, C. Roland T1 - In vivo responses of the human and murine pregnane X receptor to dexamethasone in mice JF - Drug Metabolism and Disposition N2 - Dexamethasone (DEX) is a potent and widely used anti-inflammatory and immunosuppressant glucocorticoid. It can bind and activate the pregnane X receptor (PXR), which plays a critical role as xenobiotic sensor in mammals to induce the expression of many enzymes, including cytochromes P450 in the CYP3A family. This induction results in its own metabolism. We have used a series of transgenic mouse lines, including a novel, improved humanized PXR line, to compare the induction profile of PXR-regulated drug-metabolizing enzymes after DEX administration, as well as looking at hepatic responses to rifampicin (RIF). The new humanized PXR model has uncovered further intriguing differences between the human and mouse receptors in that RIF only induced Cyp2b10 in the new humanized model. DEX was found to be a much more potent inducer of Cyp3a proteins in wild-type mice than in mice humanized for PXR. To assess whether PXR is involved in the detoxification of DEX in the liver, we analyzed the consequences of high doses of the glucocorticoid on hepatotoxicity on different PXR genetic backgrounds. We also studied these effects in an additional mouse model in which functional mouse Cyp3a genes have been deleted. These strains exhibited different sensitivities to DEX, indicating a protective role of the PXR and CYP3A proteins against the hepatotoxicity of this compound. Y1 - 2010 U6 - https://doi.org/10.1124/dmd.109.031872 SN - 1521-009X VL - 38 IS - 7 SP - 1046 EP - 1053 PB - ASPET CY - Bethesda ER - TY - JOUR A1 - Scheer, Nico A1 - Ross, Jillian A1 - Rode, Anja A1 - Zevnik, Branko A1 - Niehaves, Sandra A1 - Faust, Nicole A1 - Wolf, C. Roland T1 - A novel panel of mouse models to evaluate the role of human pregnane X receptor and constitutive androstane receptor in drug response JF - Journal of Clinical Investigation Y1 - 2008 U6 - https://doi.org/https://doi.org/10.1172/JCI35483 SN - 1558-8238 VL - 118 IS - 9 SP - 3228 EP - 3239 ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - McEwan, Jillian A1 - Beuger, Vincent A1 - Stanley, Lesley A. A1 - Rode, Anja A1 - Wolf, C. Roland T1 - Modeling Human Cytochrome P450 2D6 Metabolism and Drug-drug Interaction by a Novel Panel of Knockout and Humanized Mouse Lines JF - Molecular Pharmacology N2 - The highly polymorphic human cytochrome P450 2D6 enzyme is involved in the metabolism of up to 25% of all marketed drugs and accounts for significant individual differences in response to CYP2D6 substrates. Because of the differences in the multiplicity and substrate specificity of CYP2D family members among species, it is difficult to predict pathways of human CYP2D6-dependent drug metabolism on the basis of animal studies. To create animal models that reflect the human situation more closely and that allow an in vivo assessment of the consequences of differential CYP2D6 drug metabolism, we have developed a novel straightforward approach to delete the entire murine Cyp2d gene cluster and replace it with allelic variants of human CYP2D6. By using this approach, we have generated mouse lines expressing the two frequent human protein isoforms CYP2D6.1 and CYP2D6.2 and an as yet undescribed variant of this enzyme, as well as a Cyp2d cluster knockout mouse. We demonstrate that the various transgenic mouse lines cover a wide spectrum of different human CYP2D6 metabolizer phenotypes. The novel humanization strategy described here provides a robust approach for the expression of different CYP2D6 allelic variants in transgenic mice and thus can help to evaluate potential CYP2D6-dependent interindividual differences in drug response in the context of personalized medicine. Y1 - 2012 U6 - https://doi.org/10.1124/mol.111.075192 SN - 1521-0111 VL - 81 IS - 1 SP - 63 EP - 72 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Reugels, Alexander M. A1 - Boggetti, Barbara A1 - Scheer, Nico A1 - Campos-Ortega, José A. T1 - Asymmetric localization of Numb:EGFP in dividing neuroepithelial cells during neurulation in Danio rerio JF - Developmental Dynamics Y1 - 2006 U6 - https://doi.org/10.1002/dvdy.20699 SN - 1097-0177 VL - 235 IS - 4 SP - 934 EP - 948 ER - TY - JOUR A1 - Hans, Stefan A1 - Scheer, Nico A1 - Riedl, Iris A1 - Weizäcker, Elisabeth von A1 - Blader, Patrick A1 - Campos-Ortega, José A. T1 - her3, a zebrafish member of the hairy-E(spl) family, is repressed by Notch signalling JF - Development Y1 - 2004 U6 - https://doi.org/10.1242/dev.01167 SN - 1477-9129 VL - 131 IS - 12 SP - 2957 EP - 2969 ER -