@article{ZhangHeimbachScheeretal.2016, author = {Zhang, Jin and Heimbach, Tycho and Scheer, Nico and Barve, Avantika and Li, Wenkui and Lin, Wen and He, Handan}, title = {Clinical Exposure Boost Predictions by Integrating Cytochrome P450 3A4-Humanized Mouse Studies With PBPK Modeling}, series = {Journal of Pharmaceutical Sciences}, volume = {Volume 105}, journal = {Journal of Pharmaceutical Sciences}, number = {Issue 4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-3549}, doi = {doi.org/10.1016/j.xphs.2016.01.021}, pages = {1398 -- 1404}, year = {2016}, abstract = {NVS123 is a poorly water-soluble protease 56 inhibitor in clinical development. Data from in vitro hepatocyte studies suggested that NVS123 is mainly metabolized by CYP3A4. As a consequence of limited solubility, NVS123 therapeutic plasma exposures could not be achieved even with high doses and optimized formulations. One approach to overcome NVS123 developability issues was to increase plasma exposure by coadministrating it with an inhibitor of CYP3A4 such as ritonavir. A clinical boost effect was predicted by using physiologically based pharmacokinetic (PBPK) modeling. However, initial boost predictions lacked sufficient confidence because a key parameter, fraction of drug metabolized by CYP3A4 (ƒₘCYP3A4), could not be estimated with accuracy on account of disconnects between in vitro and in vivo preclinical data. To accurately estimate ƒₘCYP3A4 in human, an in vivo boost effect study was conducted using CYP3A4-humanized mouse model which showed a 33- to 56-fold exposure boost effect. Using a top-down approach, human ƒₘCYP3A4 for NVS123 was estimated to be very high and included in the human PBPK modeling to support subsequent clinical study design. The combined use of the in vivo boost study in CYP3A4-humanized mouse model mice along with PBPK modeling accurately predicted the clinical outcome and identified a significant NVS123 exposure boost (∼42-fold increase) with ritonavir.}, language = {en} } @article{ScheerBalimaneHaywardetal.2012, author = {Scheer, Nico and Balimane, Praveen and Hayward, Michael D. and Buechel, Sandra and Kauselmann, Gunther and Wolf, C. Roland}, title = {Generation and Characterization of a Novel Multidrug Resistance Protein 2 Humanized Mouse Line}, series = {Drug Metabolism and Disposition}, volume = {40}, journal = {Drug Metabolism and Disposition}, number = {11}, publisher = {ASPET}, address = {Bethesda, Md.}, issn = {1521-0111}, doi = {10.1124/dmd.112.047605}, pages = {2212 -- 2218}, year = {2012}, abstract = {The multidrug resistance protein (MRP) 2 is predominantly expressed in liver, intestine, and kidney, where it plays an important role in the excretion of a range of drugs and their metabolites or endogenous compounds into bile, feces, and urine. Mrp knockout [Mrp2(-/-)] mice have been used recently to study the role of MRP2 in drug disposition. Here, we describe the first generation and initial characterization of a mouse line humanized for MRP2 (huMRP2), which is nulled for the mouse Mrp2 gene and expresses the human transporter in the organs and cell types where MRP2 is normally expressed. Analysis of the mRNA expression for selected cytochrome P450 and transporter genes revealed no major changes in huMRP2 mice compared with wild-type controls. We show that human MRP2 is able to compensate functionally for the loss of the mouse transporter as demonstrated by comparable bilirubin levels in the humanized mice and wild-type controls, in contrast to the hyperbilirubinemia phenotype that is observed in MRP2(-/-) mice. The huMRP2 mouse provides a model to study the role of the human transporter in drug disposition and in assessing the in vivo consequences of inhibiting this transporter by compounds interacting with human MRP2.}, language = {en} } @article{AbulnagaPinkenburgSchiffelsetal.2013, author = {Abulnaga, El-Hussiny and Pinkenburg, Olaf and Schiffels, Johannes and E-Refai, Ahmed and Buckel, Wolfgang and Selmer, Thorsten}, title = {Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli}, series = {Journal of bacteriology}, volume = {195}, journal = {Journal of bacteriology}, number = {16}, issn = {1098-5530 [E-Journal]}, pages = {3704 -- 3713}, year = {2013}, language = {en} } @article{MeyerStorkHoeckerBerndt1992, author = {Meyer-Stork, L. Sebastian and H{\"o}cker, Hartwig and Berndt, Heinz}, title = {Syntheses and reactions of urethanes of cellobiose and cellulose-containing uretdione groups}, series = {Journal of applied polymer science}, volume = {44}, journal = {Journal of applied polymer science}, number = {6}, issn = {1097-4628}, pages = {1043 -- 1049}, year = {1992}, language = {en} } @book{Tippkoetter2010, author = {Tippk{\"o}tter, Nils}, title = {Reaktionssysteme zur Aufarbeitung und Umsetzung nachwachsender Rohstoffe : Einsatz chromatographischer Verfahren sowie Membran- und Festbettreaktoren zur Verarbeitung von Molke, St{\"a}rke und Cellulose}, publisher = {Logos-Verlag}, address = {Berlin}, isbn = {978-3-8325-2717-4}, pages = {III, 269 Seiten}, year = {2010}, language = {de} } @misc{AlKaidyUlberTippkoetter2014, author = {Al-Kaidy, H. and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Eine Plattform-Technologie f{\"u}r die automatisierte Reaktionsf{\"u}hrung in magnetisierbaren mikrofluidischen Tropfen}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450424}, pages = {1419 -- 1420}, year = {2014}, abstract = {{\"U}blicherweise werden biotechnologische Reaktionssysteme im mikrofluidischen Maßstab in vorstrukturierten Bauteilen oder mit auf Wellplatten basierenden Robotersystemen realisiert. In dem hier vorgestellten System werden chemische oder biologische Reaktionen mit magnetischen Mikroreaktoren (MR) durchgef{\"u}hrt, bei denen hydrophobe magnetische Mikropartikel einen w{\"a}ssrigen Kern umschließen. Solche MR bieten eine gute Kontrolle der Reaktionsbedingungen, eine verbesserte Sicherheit und Portabilit{\"a}t. Die neue Plattformtechnologie erm{\"o}glicht die zweidimensionale Bewegung der magnetischen MR auf einer planaren Ebene. Oberhalb oder unterhalb der Plattform werden Magnetfeldgradienten zum Manipulieren und Bewegen eines oder mehrerer magnetischer MR erzeugt. Die optimal auf die MR wirkenden magnetischen Kr{\"a}fte werden experimentell ermittelt und simuliert. Die Aktivierung der Magnetfelder wird automatisiert durch elektrische Spulen mit Eisenkern bzw. Neodymmagnet gesteuert. Angewendet wurde das System beim reversiblen {\"O}ffnen von MR, um z. B. Reaktionspartner in den w{\"a}ssrigen Kern zu injizieren oder Proben zu entnehmen. Ferner wurde Lac-case A und b-Glucosidase auf einer Quarzglasoberfl{\"a}che immobilisiert und mit einem MR zum Reagieren gebracht. Weiterhin wurden MR fusioniert und so ein w{\"a}ssriger Kern bestehend aus Laccase mit einem aus dem entsprechenden Substrat Syringaldazin vereint.}, language = {de} } @misc{RothkranzKrafftTippkoetter2022, author = {Rothkranz, Berit and Krafft, Simone and Tippk{\"o}tter, Nils}, title = {Media optimization for sustainable fuel production: How to produce biohydrogen from renewable resources with Thermotoga neapolitana}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255305}, pages = {1298 -- 1299}, year = {2022}, abstract = {Hydrogen is playing an increasingly important role in research and politics as an energy carrier of the future. Since hydrogen has commonly been produced from methane by steam reforming, the need for climate-friendly, alternative production routes is emerging. In addition to electrolysis, fermentative routes for the production of so-called biohydrogen are "green" alternatives. The application of microorganisms offers the advantage of sustainable production from renewable resources using easily manageable technologies. In this project, the hyperthermophilic, anaerobic microorganism Thermotoga neapolitana is used for the productio nof biohydrogen from renewable resources. The enzymatically hydrolyzed resources were used in fermentation leading to yield coefficients of 1.8 mole H₂ per mole glucose when using hydrolyzed straw and ryegrass supplemented with medium, respectively. These results are similar to the hydrogen yields when using Thermotoga basal medium with glucose (TBGY) as control group. In order to minimize the supplementation of the hydrolysate and thus increase the economic efficiency of the process, the essential media components were identified. The experiments revealed NaCl, KCl, and glucose as essential components for cell growth as well as biohydrogen production. When excluding NaCl, a decrease of 96\% in hydrogen production occured.}, language = {en} } @misc{VarrialeKukaTippkoetteretal.2022, author = {Varriale, Ludovica and Kuka, Katrin and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Use of a green biomass in a biorefinery platform}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255095}, pages = {1299}, year = {2022}, abstract = {The emerging environmental issues due to the use of fossil resources are encouraging the exploration of new renewable resources. Biomasses are attracting more interest due to the low environmental impacts, low costs, and high availability on earth. In this scenario, green biorefineries are a promising platform in which green biomasses are used as feedstock. Grasses are mainly composed of cellulose and hemicellulose, and lignin is available in a small amount. In this work, a perennial ryegrass was used as feedstock to develop a green bio-refinery platform. Firstly, the grass was mechanically pretreated, thus obtaining a press juice and a press cake fraction. The press juice has high nutritional values and can be employed as part of fermentation media. The press cake can be employed as a substrate either in enzymatic hydrolysis or in solid-state fermentation. The overall aim of this work was to demonstrate different applications of both the liquid and the solid fractions. For this purpose, the filamentous fungus A. niger and the yeast Y. lipolythica were selected for their ability to produce citric acid. Finally, the possibility was assessed to use the press juice as part of fermentation media to cultivate S. cerevisiae and lactic acid bacteria for ethanol and lactic acid fermentation.}, language = {en} } @techreport{Tippkoetter2021, author = {Tippk{\"o}tter, Nils}, title = {TreBec - Herstellung eines Mehrwegbechers aus Treber : Sachbericht zum Verwendungsnachweis}, publisher = {FH Aachen}, address = {J{\"u}lich}, doi = {10.2314/KXP:1858723302}, pages = {10 Seiten}, year = {2021}, abstract = {Laufzeit des Vorhabens und Berichtszeitraum: 01.10.2020-30.09.2021}, language = {de} } @misc{PothMonzonTippkoetteretal.2009, author = {Poth, S. and Monzon, M. and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Fermentation von Hydrolysaten aus Lignocellulose}, series = {Chemie Ingenieur Technik}, volume = {81}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.200950243}, pages = {1220}, year = {2009}, abstract = {Die {\"o}konomische Abh{\"a}ngigkeit von fossilen Brennstoffen und der klimatische Wandel durch die Nutzung dieser haben zu einer intensiven Suche nach erneuerbaren Rohstoffen f{\"u}r die Produktion von Chemikalien und Treibstoffen gef{\"u}hrt. Ein viel versprechender Rohstoff in diesem Zusammenhang sind Zucker, die mittels enzymatischer Hydrolyse aus Lignocellulose gewonnen werden k{\"o}nnen. Die Fermentation erfolgt mit Cellulose- bzw. Hemicellulose-Fraktionen, welche durch thermo-chemische Vorbehandlung von Holz gewonnen und anschließend enzymatisch hydrolysiert werden. Die in den Hydrolysaten enthaltenen Zuckermonomere dienen als Kohlenstoffquelle f{\"u}r die Produktion von Ethanol. Da sowohl Glucose als auch Xylose in den unterschiedlichen Fraktionen enthalten sind, wird zur Umsetzung dieser eine Co-Fermentation zweier Hefen durchgef{\"u}hrt. Im Rahmen der Optimierung dieser Fermentationen werden neben der Erg{\"a}nzung der Hydrolysate durch notwendige Salze auch Verfahrenweisen wie Fed-Batch-Fermentationen untersucht. Ein weiterer interessanter Ansatz, welcher in diesem Rahmen gepr{\"u}ft wird, ist die enzymatische Hydrolyse der Lignocellulose-Fraktionen und die simultane Fermentation der dabei entstehenden Zucker in einem Schritt. Des Weiteren wurde die Eignung der Hydrolysate f{\"u}r die Biomasseproduktion anderer Mikroorganismen wie Escherichia coli getestet.}, language = {de} } @book{WagemannTippkoetter2019, author = {Wagemann, Kurt and Tippk{\"o}tter, Nils}, title = {Biorefineries / Kurt Wagemann, Nils Tippk{\"o}tter (editors)}, series = {Advances in biochemical engineering/biotechnology book series (ABE)}, journal = {Advances in biochemical engineering/biotechnology book series (ABE)}, publisher = {Springer}, address = {Cham (Switzerland)}, isbn = {978-3-319-97117-9}, doi = {10.1007/978-3-319-97119-3}, pages = {VI, 549 Seiten}, year = {2019}, language = {en} } @misc{TippkoetterDuweRaisetal.2014, author = {Tippk{\"o}tter, Nils and Duwe, Anna and Rais, Dominik and Zibek, Susanne and Zorn, H.}, title = {Optimierung und Scale-up der enzymatischen Hydrolyse inkl. Ligninabbau}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450287}, pages = {1515}, year = {2014}, abstract = {Prim{\"a}re Ziele der Hydrolyse pflanzlicher nachwachsender Rohstoffe sind m{\"o}glichst hohe Zuckerkonzentrationen f{\"u}r nachfolgende Fermentationen und eine Maximierung der Produktivit{\"a}t. Zur Optimierung dieser Prozesse wird Organosolv-aufgeschlossene Buchenholz-Cellulose verwendet. Die Hydrolyse des Faserstoffes erfolgt mithilfe von Novozymes CTec2-Enzymen. Die Hydrolysen konnten durch neue R{\"u}hrerelemente auf einen Maßstab von 1000 L {\"u}bertragen werden. Dabei konnten maximale Ausbeuten (g Glucose g -1 Glucose im Faserstoff) bis 81 g g - 1 und Konzentrationen von 152 g L -1 erreicht werden. Zurzeit k{\"o}nnen unter Einsatz eines Feststoffreaktors Cellulosefasern in einer Konzentration bis 400 g L -1 enzymatisch hydrolysiert werden. Die cellulolytischen Enzyme stoßen bei hohen Feststoffkonzentrationen an ihre Grenzen. Mit steigendem Feststoffgehalt nimmt die Hydrolyseausbeute ab. Ein Ansatz zur Steigerung der Effizienz ist der Einsatz ligninolytischer Enzyme, die Ligninreste an der Organosolv-Cellulose aufschließen k{\"o}nnen. Eine solche Verbesserung der Zug{\"a}nglichkeit f{\"u}r cellulolytische Enzyme an ihr Substrat wurde durch Kultur{\"u}berst{\"a}nde verschiedener ligninolytischer Pilze erreicht. Mit Kultur{\"u}berst{\"a}nden von Stereum sp. sind Steigerungen der Glucoseausbeuten um bis zu 30 \% m{\"o}glich.}, language = {de} } @article{BerndtKlostermeyerZahn1972, author = {Berndt, Heinz and Klostermeyer, Henning and Zahn, Helmut}, title = {Zur Synthese monomerer cyclischer Cystinpeptidderivate, I : Synthese der Sequenz A 6-9 des Schafinsulins als Cyclocystinylderivat}, series = {Justus Liebigs Annalen der Chemie}, volume = {759}, journal = {Justus Liebigs Annalen der Chemie}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1099-0690}, doi = {10.1002/jlac.19727590109}, pages = {114 -- 120}, year = {1972}, abstract = {Es wird die Synthese der Sequenz A 6-9 des Schafinsulins in der gesch{\"u}tzten Form Boc-Cys-Cys-Ala-Gly-OBuᵗ (5) sowie das Verhalten dieses monomeren cyclischen Cystinpeptidderivates gegen{\"u}ber den in der Peptidchemie gebr{\"a}uchlichen Reagenzien Bortrifluorid/Eisessig, Tri{\"a}thylamin und Hydrazinhydrat beschrieben.}, language = {de} } @book{Berndt2014, author = {Berndt, Heinz}, title = {Neue Kondensations-Methoden zur Synthese definierter Peptid-Derivate}, address = {Aachen}, pages = {XII, VI, 207 S. : graph. Darst.}, year = {2014}, language = {de} } @misc{RossJonesTeumerCapitainetal.2018, author = {Ross-Jones, J. and Teumer, T. and Capitain, C. and Tippk{\"o}tter, Nils and Krause, M. J. and Methner, F.-J. and R{\"a}dle, M.}, title = {Analytical methods for in-line characterization of beer haze}, series = {Trends in Brewing}, journal = {Trends in Brewing}, year = {2018}, abstract = {In most beers, producers strive to minimize haze to maximize visual appeal. To detect the formation of particulates, a measurement system for sub-micron particles is required. Beer haze is naturally occurring, composed of protein or polyphenol particles; in their early stage of growth their size is smaller than 2 µm. Microscopy analysis is time and resource intensive; alternatively, backscattering is an inexpensive option for detecting particle sizes of interest.}, language = {en} } @incollection{OezdilBerndtHoecker1991, author = {{\"O}zdil, S. and Berndt, Heinz and H{\"o}cker, Hartwig}, title = {Systematische Erfassung der Best{\"a}ndigkeit von Ryton-, P84- und Dralon ATF 1063-Fasern unter Einwirkung verschiedener NOx-Konzentrationen in einem definierten Temperaturintervall}, series = {Schriftenreihe des Deutschen Wollforschungsinstitutes an der Technischen Hochschule Aachen e.V.}, booktitle = {Schriftenreihe des Deutschen Wollforschungsinstitutes an der Technischen Hochschule Aachen e.V.}, number = {107}, publisher = {Dt. Wollforschungsinstitut}, address = {Aachen}, issn = {0930-3723}, pages = {89 -- 129}, year = {1991}, language = {de} } @inproceedings{SchnabelBerndt1973, author = {Schnabel, Eberhard and Berndt, Heinz}, title = {Zur selektive Abspaltbarkeit der t-Butyloxycarbonylgruppe}, series = {Peptides 1971 : proceedings of the Eleventh European Peptide Symposium, Vienna, Austria, April 1971}, booktitle = {Peptides 1971 : proceedings of the Eleventh European Peptide Symposium, Vienna, Austria, April 1971}, editor = {Nesvadba, H.}, publisher = {North-Holland Publ. [u.a.]}, address = {Amsterdam [u.a.]}, isbn = {0-7204-4120-X}, pages = {69 -- 70}, year = {1973}, language = {en} } @misc{TippkoetterMoehring2014, author = {Tippk{\"o}tter, Nils and M{\"o}hring, S.}, title = {Nutzung von F{\"a}ulepilzen f{\"u}r die selektive Gewinnung von Cellulose und Lignin aus nicht vorbehandelter lignocellulosehaltiger Biomasse}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450353}, pages = {1385}, year = {2014}, abstract = {Einige Arten der Braun- und Weißf{\"a}ulepilze sind in der Lage, selektiv entweder Lignin oder Cellulose im Holz abzubauen. Diese Pilze k{\"o}nnen f{\"u}r eine energiesparende Vorbehandlung lignocellulosehaltiger Biomasse f{\"u}r Bioraffinerien genutzt werden, ohne auf technisch aufw{\"a}ndige Aufschlussapparate zur{\"u}ckgreifen zu m{\"u}ssen. Weißf{\"a}ulepilze bauen bevorzugt Lignin ab, wodurch die verbleibende Cellulose leichter f{\"u}r enzymatische Hydrolysen in das Monosaccharid Glucose zug{\"a}nglich wird. Braunf{\"a}ulepilze bauen dagegen Cellulose und Hemicellulose ab. Die Auswirkungen der Behandlung von Weizenstroh mit verschiedenen Pilzarten werden zurzeit untersucht. Dabei werden die Ver{\"a}nderung der enzymatischen Hydrolysierbarkeit des Substrats sowie die gebildeten Ligninderivate bestimmt. Detaillierte Betrachtungen der Biomassever{\"a}nderung werden mithilfe spezifischer F{\"a}rbemethoden durchgef{\"u}hrt, durch die morphologische Ver{\"a}nderungen der Pflanzengewebe in der 3D-Lichtmikroskopie dargestellt werden k{\"o}nnen.}, language = {de} } @misc{PasteurLudwigTippkoetteretal.2010, author = {Pasteur, A. and Ludwig, B. and Tippk{\"o}tter, Nils and Diller, R. and Kampeis, P. and Ulber, Roland}, title = {Aufarbeitung von β-Lactamantibiotika mittels selektiver, magnetischer Adsorbermaterialien}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201050270}, pages = {1587}, year = {2010}, abstract = {b-Lactame geh{\"o}ren zu den wirkungsvollsten Antibiotika, jedoch lassen sich viele nur schwierig fermentativ erzeugen. Ein Problem bei der fermentativen Produktion ist die Hydrolyse des Lactamrings im w{\"a}ssrigen Milieu. Das Ziel des von der DBU gef{\"o}rderten Projekts ist die selektive In-situ-Adsorption der b-Lactamantibiotika unter anschließender magnetischer Separation. Durch die Isolation im Hochgradientenmagnetseparator (HGMS) ist eine Fest-fest-fl{\"u}ssig-Trennung und somit ein erheblicher Zeitgewinn im Downstreamprozess m{\"o}glich. Zus{\"a}tzlich kommt es zur Einsparung an L{\"o}sungsmittel und Energie, was neben Reduzierung der Antibiotikahydrolyse auch in {\"o}kologischer Hinsicht einen interessanten Aspekt darstellt. Als Tr{\"a}germaterial f{\"u}r die Adsorbermatrix werden magnetisierbare Eisenoxidpartikel eingesetzt, die in einer Silikamatrix eingebettet sind. Diese Adsorber sollen auf Selektivit{\"a}t in Wasser und verschiedenen Medien getestet werden. Zus{\"a}tzlich werden die Abbauprodukte des b-Lactams analysiert, um eine Aussage {\"u}ber die Stabilisierung des Antibiotikums durch die selektiven Adsorber treffen zu k{\"o}nnen. Diese Ergebnisse werden mit kommerziell erh{\"a}ltlichen Adsorbern verglichen. Die Aufreinigung der Antibiotika soll direkt aus der Fermentationsbr{\"u}he erfolgen. Um die Trennung der magnetischen, selektiven Adsorber von der Biomasse zu gew{\"a}hrleisten, soll der HGMS in die Fermentation integriert werden. Das filament{\"o}se Wachstum des Mikroorganismus erfordert eine Neuauslegung der Filtermatrix.}, language = {de} } @misc{HeringUlberTippkoetter2014, author = {Hering, T. and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Aktiver und passiver antimikrobieller Oberfl{\"a}chenschutz durch funktionalisierte Mikropartikel}, series = {Chemie Ingenieur Technik}, volume = {9}, journal = {Chemie Ingenieur Technik}, number = {86}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450264}, pages = {1474 -- 1475}, year = {2014}, abstract = {Mikrobielle Verunreinigungen von Oberfl{\"a}chen in technischen und medizinischen Systemen sind allgegenw{\"a}rtig. Sie basieren {\"u}blicherweise auf adsorptiven Oberfl{\"a}chenbindungen organischer Komponenten (Proteine und Fette) oder Membrankomponenten aerogener sowie wassergebundener Mikroorganismen. In laufenden Forschungsarbeiten wird eine aktive sowie passive Biomodifikation von Oberfl{\"a}chen zu deren Schutz vor Adsorption von Proteinen und Mikroorganismen verfolgt. Der antimikrobielle Schutz soll dabei sowohl durch die Mikrostrukturierung bzw. Rauheitsanpassung der Oberfl{\"a}chen durch deren Beschichtung mit Mikro-und Nanopartikeln erfolgen. Ferner werden antimikrobielle Enzyme und funktionelle Gruppen auf den Mikropartikeln gebunden, um den Oberfl{\"a}chenschutz zu verst{\"a}rken. In ersten Versuchen wurden quart{\"a}re Ammoniumverbindungen auf eigens synthetisierten superparamagnetischen Eisenoxid-Nanopartikeln (Durchmesser 10 - 30 nm) immobilisiert und die wachstumshemmende Wirkung untersucht. Erste Ergebnisse zeigten, dass eine Konzentration von 10 mg mL⁻¹ der Ammoniumverbindung in einer Wachstumshemmung des verwendeten Gram-negativen Modell-Mikroorganismus E. coli GFPmut2 resultiert. Zurzeit werden synergistisch wirkende Kombinationen von Partikeln mit Proteasen, quart{\"a}ren Ammoniumverbindungen, hydrophoben Oberfl{\"a}chen und mikrostrukturierten Oberfl{\"a}chen als antimikrobieller Schutz untersucht.}, language = {de} } @inproceedings{BerndtKalbeKuropkaetal.1989, author = {Berndt, Heinz and Kalbe, Jochen and Kuropka, Rolf and Meyer-Stork, L. Sebastian and Sauter, S. L. and H{\"o}cker, Hartwig}, title = {Eindeutige Charakterisierung von Tierhaaren und Tierhaar-Mischungen durch DNA-Analytik}, series = {Beitr{\"a}ge zur 15. Gemeinsamen Tagung der Aachener Textilforschungsinstitute und des "Wollfadens", zugleich 32. Arbeitstagung des Deutschen Wollforschungsinstitutes an der Technischen Hochschule Aachen : am 06. und 07. Oktober 1988. - (Schriftenreihe des Deutschen Wollforschungsinstituts an der Technischen Hochschule Aachen e. V. ; 104)}, booktitle = {Beitr{\"a}ge zur 15. Gemeinsamen Tagung der Aachener Textilforschungsinstitute und des "Wollfadens", zugleich 32. Arbeitstagung des Deutschen Wollforschungsinstitutes an der Technischen Hochschule Aachen : am 06. und 07. Oktober 1988. - (Schriftenreihe des Deutschen Wollforschungsinstituts an der Technischen Hochschule Aachen e. V. ; 104)}, publisher = {Dt. Wollforschungsinst.}, address = {Aachen}, issn = {0930-3723}, pages = {29 -- 32}, year = {1989}, language = {de} } @article{ZhantlessovaSavitskayaKistaubayevaetal.2022, author = {Zhantlessova, Sirina and Savitskaya, Irina and Kistaubayeva, Aida and Ignatova, Ludmila and Talipova, Aizhan and Pogrebnjak, Alexander and Digel, Ilya}, title = {Advanced "Green" prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy}, series = {Polymers}, volume = {14}, journal = {Polymers}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym14153224}, pages = {Artikel 3224}, year = {2022}, abstract = {Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for "grafting" of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality.}, language = {en} } @article{DallasSalphatiGomezZepedaetal.2016, author = {Dallas, Shannon and Salphati, Laurent and Gomez-Zepeda, David and Wanek, Thomas and Chen, Liangfu and Chu, Xiaoyan and Kunta, Jeevan and Mezler, Mario and Menet, Marie-Claude and Chasseigneaux, Stephanie and Decl{\`e}ves, Xavier and Langer, Oliver and Pierre, Esaie and DiLoreto, Karen and Hoft, Carolin and Laplanche, Loic and Pang, Jodie and Pereira, Tony and Andonian, Clara and Simic, Damir and Rode, Anja and Yabut, Jocelyn and Zhang, Xiaolin and Scheer, Nico}, title = {Generation and Characterization of a Breast Cancer Resistance Protein Humanized Mouse Model}, series = {Molecular Pharmacology}, volume = {89}, journal = {Molecular Pharmacology}, number = {5}, publisher = {ASPET}, address = {Bethesda, Md.}, issn = {1521-0111}, doi = {10.1124/mol.115.102079}, pages = {492 -- 504}, year = {2016}, abstract = {Breast cancer resistance protein (BCRP) is expressed in various tissues, such as the gut, liver, kidney and blood brain barrier (BBB), where it mediates the unidirectional transport of substrates to the apical/luminal side of polarized cells. Thereby BCRP acts as an efflux pump, mediating the elimination or restricting the entry of endogenous compounds or xenobiotics into tissues and it plays important roles in drug disposition, efficacy and safety. Bcrp knockout mice (Bcrp-/-) have been used widely to study the role of this transporter in limiting intestinal absorption and brain penetration of substrate compounds. Here we describe the first generation and characterization of a mouse line humanized for BCRP (hBCRP), in which the mouse coding sequence from the start to stop codon was replaced with the corresponding human genomic region, such that the human transporter is expressed under control of the murine Bcrp promoter. We demonstrate robust human and loss of mouse BCRP/Bcrp mRNA and protein expression in the hBCRP mice and the absence of major compensatory changes in the expression of other genes involved in drug metabolism and disposition. Pharmacokinetic and brain distribution studies with several BCRP probe substrates confirmed the functional activity of the human transporter in these mice. Furthermore, we provide practical examples for the use of hBCRP mice to study drug-drug interactions (DDIs). The hBCRP mouse is a promising model to study the in vivo role of human BCRP in limiting absorption and BBB penetration of substrate compounds and to investigate clinically relevant DDIs involving BCRP.}, language = {en} } @misc{DuweSchlegelTippkoetteretal.2014, author = {Duwe, A. and Schlegel, C. and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Sequentielle Extraktion von Cellulose zur effizienten Nutzung der Stoffstr{\"o}me in der Holzbioraffinerie}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450308}, pages = {1400}, year = {2014}, abstract = {In der Reihe der nachwachsenden Rohstoffe besitzt Holz als erneuerbare und umweltfreundliche Ressource ein großes Potenzial. {\"U}ber 11 Mio. ha Holz, das laut der Fachagentur f{\"u}r nachwachsende Rohstoffe (FNR) auch f{\"u}r industrielle Zwecke genutzt werden kann, wuchsen im Jahr 2013 allein auf bundesdeutscher Fl{\"a}che. 56,8 Mio. m³ j{\"a}hrlicher Holzeinschlag in den letzten zehn Jahren wurde zu knapp der H{\"a}lfte stofflich und der Rest energetisch verwertet. Im Rahmen dieser Arbeit konnte auf der Basis vom Holz der Buche, die nach Fichte und Kiefer die dritth{\"a}ufigste Baumart in Deutschland ist und 15\% der deutschen Waldfl{\"a}che ausmacht, die Fraktionierung der polymeren Hauptbestandteile mit niedrigem energetischen Einsatz erreicht werden. Hierbei werden in einem nachgeschalteten Extraktionsprozess die beiden Komponenten Hemicellulose und Lignin in fl{\"u}ssiger Form von der finalen festen Cellulosefraktion abgetrennt. Die Extraktion der Hemicellulose erfolgt durch eine Liquid Hot Water (LHW)-Behandlung. Untersucht wird der katalytische Zusatz anorganischer S{\"a}uren wie H₃PO₄ und H₂SO₄. Im Hinblick auf die weitere Verwertung von Lignin zu aromatischen Synthesebausteinen kommt die Organosolv-Extraktion mit einem Ethanol/Wasser-Gemisch zum Einsatz. Von Vorteil ist die weitere Verwendung beider Stoffstr{\"o}me ohne F{\"a}llungsschritt und nachteiliger Verd{\"u}nnung der Hemicellulose.}, language = {en} } @incollection{HahnKellyMuffleretal.2011, author = {Hahn, Thomas and Kelly, Svenja and Muffler, Kai and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Extraction of lignocellulose and algae for the production of bulk and fine chemicals}, series = {Industrial scale natural products extraction}, booktitle = {Industrial scale natural products extraction}, editor = {Hans-J{\"o}rg, Bart and Pilz, Stephan}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-32504-7 (Print)}, doi = {10.1002/9783527635122}, pages = {221 -- 245}, year = {2011}, language = {en} } @misc{AlKaidyTippkoetterKaiseretal.2014, author = {Al-Kaidy, H. and Tippk{\"o}tter, Nils and Kaiser, P. and Wollny, S. and Ulber, Roland}, title = {Aufreinigung von Cytochrom P450BMP mittels magnetischer Partikel und die enzymatische Synthese von 9, 10-Dihydroxystearins{\"a}ure}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450420}, pages = {1420}, year = {2014}, abstract = {Cytochrom P450 sind H{\"a}m-Proteine, die zur Enzymklasse der Oxidoreduktasen (EC 1.14.xy) geh{\"o}ren. Eine wichtige Reaktion ist die Hydroxylierung nichtaktivierter C-H-Bindungen, die in technischen Systemen von großem Interesse ist. Durch die Verwendung von M-IDA-2-Partikeln ist eine direkte Aufreinigung mit gleichzeitiger Immobilisierung und die Applikation der Enzyme aus dem Zelllysat m{\"o}glich. Damit ist das Verfahren mehr als f{\"u}nf Stunden schneller als die konventionelle Chromatographie und mehr als 80 \% der Aufreinigungszeit wird gespart. Mit dem isolierten nativen Enzym konnte die Plattformchemikalie 9,10-Dihydroxystearins{\"a}ure aus {\"O}ls{\"a}ure hergestellt werden. Unter anderem f{\"u}r die Kunststoffindustrie k{\"o}nnen aus diesem Produkt wichtige Monomere wie z. B. Azelains{\"a}ure hergestellt werden. Die Bildung des Produkts erfolgt in einem zweiphasigen Reaktionssystem an der Grenzfl{\"a}che zwischen dem {\"O}l und der w{\"a}ssrigen Phase als Feststoff. Um das immobilisierte Enzym aktiv in die obere Phase zu transportieren, wurde eine neue magnetische Mischvorrichtung entwickelt. Das Reaktionsprodukt wurde mit NMR, GC-MS und HPLC-MS analysiert und mit einem chemisch synthetisierten Standard von 9,10-Dihydroxystearins{\"a}ure verglichen. Derzeit werden Studien des immobilisierten H{\"a}ms des Enzyms durchgef{\"u}hrt.}, language = {de} } @misc{HeringUlberTippkoetter2016, author = {Hering, T. and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Antimikrobielle Oberfl{\"a}chenmodifikation durch Mikropartikel}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201650084}, pages = {1302}, year = {2016}, abstract = {Die Ausbildung von Biofilmen in technischen Anlagen, wie z. B. K{\"u}hlkreisl{\"a}ufen, Wasseraufbereitungssystemen und Bioreaktoren, f{\"u}hren zu Materialsch{\"a}den (Biofouling) und stark erh{\"o}htem Energieaufwand. Im Rahmen der aktuellen Forschungsarbeiten erfolgen aktive sowie passive Bio-Modifikationen auf funktionalisierten magnetischen Mikropartikelober-fl{\"a}chen. Um die verschiedenen funktionalisierten magnetischen Mikropartikel zu analysieren und ihre antimikrobielle Wirkung zu testen, wird der Einsatz einer 3D-gedruckten, magnetischen Plattform f{\"u}r ein Fluoreszenz-basiertes Screening-System untersucht. F{\"u}r den Oberfl{\"a}chenschutz wurden verschiedene, antimikrobiell funktionalisierte Partikelkombinationen mit dem Mikroorganismus Escherichia coli GFPmut2 in Bezug auf aktiven Oberfl{\"a}chenschutz verglichen. Um die antimikrobielle Oberfl{\"a}cheneffekte von synergistischen Kombinationen unterschiedlich funktionalisierter Partikel zu bestimmen, werden Oberfl{\"a}chen einem Magnetfeld ausgesetzt, das die Mikropartikel als definierte Schicht auf ihnen zur{\"u}ck h{\"a}lt. Diese modifizierten Oberfl{\"a}chen k{\"o}nnen sowohl durch Fluoreszenzspektroskopie als auch -mikroskopie analysiert werden.}, language = {de} } @article{Berndt1979, author = {Berndt, Heinz}, title = {Synthese der Sequenz 71—86 des Humanproinsulins, I : Synthese der Sequenz 71—86 als monomeres cyclisches Biscystinpeptidderivat und als Tetra-S-tritylderivat}, series = {Hoppe-Seyler's Zeitschrift f{\"u}r physiologische Chemie}, volume = {360}, journal = {Hoppe-Seyler's Zeitschrift f{\"u}r physiologische Chemie}, number = {1}, issn = {1437-4315}, doi = {10.1515/bchm2.1979.360.1.747}, pages = {747 -- 760}, year = {1979}, language = {de} } @article{TeumerCapitainRossJonesetal.2018, author = {Teumer, T. and Capitain, C. and Ross-Jones, J. and Tippk{\"o}tter, Nils and R{\"a}dle, M. and Methner, F.-J.}, title = {In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor}, series = {BrewingScience}, volume = {71}, journal = {BrewingScience}, number = {5/6}, publisher = {Fachverlag Hans Carl}, address = {N{\"u}rnberg}, issn = {1613-2041}, pages = {49 -- 55}, year = {2018}, abstract = {In the present work an optical sensor in combination with a spectrally resolved detection device for in-line particle-size-monitoring for quality control in beer production is presented. The principle relies on the size and wavelength dependent backscatter of growing particles in fluids. Measured interference structures of backscattered light are compared with calculated theoretical values, based on Mie-Theory, and fitted with a linear least square method to obtain particle size distributions. For this purpose, a broadband light source in combination with a process-CCD-spectrometer (charge ? coupled device spectrometer) and process adapted fiber optics are used. The goal is the development of an easy and flexible measurement device for in-line-monitoring of particle size. The presented device can be directly installed in product fill tubes or vessels, follows CIP- (cleaning in place) and removes the need of sample taking. A proof of concept and preliminary results, measuring protein precipitation, are presented.}, language = {en} } @techreport{TippkoetterWagner2019, author = {Tippk{\"o}tter, Nils and Wagner, Sebastian}, title = {Biomimetischer Klebstoff aus ligninhaltigen Pflanzenresten (Teilvorhaben 1 und 2) : Schlussbericht zum Vorhaben : Laufzeit: 01.01.2016 bis 31.03.2019}, publisher = {FH Aachen}, address = {J{\"u}lich}, doi = {10.2314/KXP:169732777X}, pages = {109 S.}, year = {2019}, language = {de} } @article{RoeschKratzHeringetal.2016, author = {R{\"o}sch, C. and Kratz, F. and Hering, T. and Trautmann, S. and Umanskaya, N. and Tippk{\"o}tter, Nils and M{\"u}ller-Renno, C.M. and Ulber, Roland and Hannig, M. and Ziegler, C.}, title = {Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity}, series = {Colloids and Surfaces B: Biointerfaces}, volume = {149}, journal = {Colloids and Surfaces B: Biointerfaces}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.colsurfb.2016.09.048}, pages = {115 -- 121}, year = {2016}, abstract = {The interplay of albumin (BSA) and lysozyme (LYZ) adsorbed simultaneously on titanium was analyzed by gel electrophoresis and BCA assay. It was found that BSA and lysozyme adsorb cooperatively. Additionally, the isoelectric point of the respective protein influences the adsorption. Also, the enzymatic activity of lysozyme and amylase (AMY) in mixtures with BSA was considered with respect to a possible influence of protein-protein interaction on enzyme activity. Indeed, an increase of lysozyme activity in the presence of BSA could be observed. In contrast, BSA does not influence the activity of amylase.}, language = {en} } @article{MolinnusBaeckerSiegertetal.2015, author = {Molinnus, Denise and B{\"a}cker, Matthias and Siegert, Petra and Willenberg, H. and Poghossian, Arshak and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Detection of Adrenaline Based on Substrate Recycling Amplification}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.708}, pages = {540 -- 543}, year = {2015}, abstract = {An amperometric enzyme biosensor has been applied for the detection of adrenaline. The adrenaline biosensor has been prepared by modification of an oxygen electrode with the enzyme laccase that operates at a broad pH range between pH 3.5 to pH 8. The enzyme molecules were immobilized via cross-linking with glutaraldehyde. The sensitivity of the developed adrenaline biosensor in different pH buffer solutions has been studied.}, language = {en} } @article{TippkoetterWollnyKampeisetal.2011, author = {Tippk{\"o}tter, Nils and Wollny, S. and Kampeis, P. and Oster, J. and Schneider, H. and Ulber, Roland}, title = {Magnetseparation von Proteinen : Separation von Zielmolek{\"u}len durch hochselektive Aptamere}, series = {GIT Labor-Fachzeitschrift}, volume = {55}, journal = {GIT Labor-Fachzeitschrift}, number = {10}, publisher = {Wiley}, address = {Weinheim}, pages = {666}, year = {2011}, abstract = {Durch die Kombination von Oligonukleotid-Liganden (Aptameren) hoher Bindungsaffinit{\"a}ten mit hochselektiv abtrennbaren magnetisierbaren Mikropartikeln wird eine einstufige Separation von Zielmolek{\"u}len aus mikrobiologischen Produktionsans{\"a}tzen m{\"o}glich. Die Aptamere werden hierf{\"u}r reversibel auf den Partikeloberfl{\"a}chen gebunden und f{\"u}r die spezifische Isolierung von Bioprodukten eingesetzt. Die Abtrennung der beladenen Partikel erfolgt durch einen neuen Rotor-Stator-Separator mit Hochgradient-Magnetfeld.}, language = {de} } @incollection{WagemannTippkoetter2018, author = {Wagemann, Kurt and Tippk{\"o}tter, Nils}, title = {Biorefineries: a short introduction}, series = {Biorefineries}, booktitle = {Biorefineries}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-97117-9}, doi = {10.1007/10_2017_4}, pages = {1 -- 11}, year = {2018}, abstract = {The terms bioeconomy and biorefineries are used for a variety of processes and developments. This short introduction is intended to provide a delimitation and clarification of the terminology as well as a classification of current biorefinery concepts. The basic process diagrams of the most important biorefinery types are shown.}, language = {en} } @article{WulfhorstDuweMerseburgetal.2016, author = {Wulfhorst, Helene and Duwe, Anna-Maria and Merseburg, Johannes and Tippk{\"o}tter, Nils}, title = {Compositional analysis of pretreated (beech) wood using differential scanning calorimetry and multivariate data analysis}, series = {Tetrahedron}, volume = {72}, journal = {Tetrahedron}, number = {46}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.tet.2016.04.029}, pages = {7329 -- 7334}, year = {2016}, abstract = {The composition of plant biomass varies depending on the feedstock and pre-treatment conditions and influences its processing in biorefineries. In order to ensure optimal process conditions, the quantitative proportion of the main polymeric components of the pre-treated biomass has to be determined. Current standard procedures for biomass compositional analysis are complex, the measurements are afflicted with errors and therefore often not comparable. Hence, new powerful analytical methods are urgently required to characterize biomass. In this contribution, Differential Scanning Calorimetry (DSC) was applied in combination with multivariate data analysis (MVA) to detect the cellulose content of the plant biomass pretreated by Liquid Hot Water (LHW) and Organosolv processes under various conditions. Unlike conventional techniques, the developed analytic method enables the accurate quantification of monosaccharide content of the plant biomass without any previous sample preparation. It is easy to handle and avoids errors in sample preparation.}, language = {en} } @techreport{Tippkoetter2018, author = {Tippk{\"o}tter, Nils}, title = {Lokale Vorbehandlung nachwachsender Rohstoffe f{\"u}r Bioraffinerien (BioSats) : Schlussbericht zum Vorhaben : Laufzeit: 01.03.2012 bis 30.04.2017}, organization = {Technische Universit{\"a}t Kaiserslautern}, doi = {10.2314/GBV:1024204243}, pages = {191 Seiten}, year = {2018}, language = {de} } @article{WackwitzBongaertsGoodmanetal.1999, author = {Wackwitz, B. and Bongaerts, Johannes and Goodman, S. D. and Unden, Gottfried}, title = {Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significance}, series = {Molecular and general genetics : MGG}, volume = {Vol. 262}, journal = {Molecular and general genetics : MGG}, number = {Iss. 4 - 5}, issn = {1617-4623 (E-Journal); 1617-4615 (Print)}, pages = {876 -- 883}, year = {1999}, language = {en} } @article{TippkoetterRoikaewUlber2008, author = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland}, title = {Nitrate removal from whey concentrate with biotechnological regeneration of the waste water}, series = {European dairy magazine : EDM}, journal = {European dairy magazine : EDM}, number = {1}, isbn = {0936-6318}, pages = {30 -- 32}, year = {2008}, language = {en} } @article{UndenBeckerBongaertsetal.1995, author = {Unden, G. and Becker, S. and Bongaerts, Johannes and Holighaus, G. and Schirawski, J. and Six, S.}, title = {O2-sensing and O2-dependent gene regulation in facultatively anaerobic bacteria}, series = {Archives of microbiology}, volume = {Vol. 164}, journal = {Archives of microbiology}, number = {Iss. 2}, issn = {1432-072X (E-Journal); 0003-9276 (Print); 0302-8933 (Print)}, pages = {81 -- 90}, year = {1995}, language = {en} } @inproceedings{TippkoetterStueckmannWinkelmannetal.2007, author = {Tippk{\"o}tter, Nils and St{\"u}ckmann, H. and Winkelmann, G. and Noack, U. and Beutel, S. and Scheper, T. and Ulber, Roland}, title = {Optimisation of antibody-labelling of gold colloids for their application in an immunchromatographic assay for microcystin-LR}, series = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme}, booktitle = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme}, publisher = {Dechema}, address = {Frankfurt am Main}, pages = {126}, year = {2007}, language = {en} } @misc{AlKaidyTippkoetterUlber2016, author = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Vorrichtung und Verfahren zur Bestimmung des Kontaktwinkels eines Fl{\"u}ssigk{\"o}rpers mit einer Festk{\"o}rperoberfl{\"a}che}, year = {2016}, abstract = {Die vorliegende Erfindung betrifft eine Vorrichtung und ein Verfahren zur Bestimmung des Kontaktwinkels eines fl{\"u}ssigen oder mit Fl{\"u}ssigkeit gef{\"u}llten K{\"o}rpers. Dieser besteht aus einem Tr{\"a}ger (1) und einer damit verbundenen, in einem Winkelbereich von mehr als 0 ° bis maximal 90 ° neigbaren Ebene (8) mit einer darin ausgebildeten Abrollbahn (9) f{\"u}r den fl{\"u}ssigen oder mit Fl{\"u}ssigkeit gef{\"u}llten K{\"o}rper. An der Ebene (8) sind mehrere Sensoren (11,12) zur Erfassung der Rolldauer des K{\"o}rpers entlang der Rollstrecke angeordnet. Erfindungsgem{\"a}ß ist vorgesehen, dass die Einstellung des Neigungswinkels der Ebene (8) {\"u}ber ein Winkelmessger{\"a}t (10) erfolgt, wodurch ein Abrollwinkel erfassbar ist, bei dem der K{\"o}rper in Bewegung ger{\"a}t. Aus der Rolldauer, der Rollstrecke und dem Abrollwinkel wird der Kontaktwinkel des K{\"o}rpers ermittelt.}, language = {de} } @article{TippkoetterDeterdingUlber2008, author = {Tippk{\"o}tter, Nils and Deterding, A. and Ulber, Roland}, title = {Determination of acetic acid in fermentation broth by gas-diffusion technique}, series = {Engineering in Life Sciences}, volume = {8}, journal = {Engineering in Life Sciences}, number = {1, Special Issue: Technical Systems for the Use in Life Sciences}, doi = {10.1002/elsc.200820227}, pages = {62 -- 67}, year = {2008}, abstract = {Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5-5.0 g/L acetic acid with a relative standard deviation of <5 \% was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents.}, language = {en} } @article{BaeckerRakowskiPoghossianetal.2013, author = {B{\"a}cker, Matthias and Rakowski, D. and Poghossian, Arshak and Biselli, Manfred and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis}, series = {Journal of Biotechnology}, volume = {163}, journal = {Journal of Biotechnology}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2012.03.014}, pages = {371 -- 376}, year = {2013}, abstract = {A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses.}, language = {en} } @article{TranBongaertsVladetal.1997, author = {Tran, Quang Hon and Bongaerts, Johannes and Vlad, Dorina and Unden, Gottfried}, title = {Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications}, series = {European journal of biochemistry}, volume = {Vol. 244}, journal = {European journal of biochemistry}, number = {Iss. 1}, issn = {0014-2956}, pages = {155 -- 160}, year = {1997}, language = {en} } @article{WiegandVoigtAlbrechtetal.2013, author = {Wiegand, Sandra and Voigt, Birgit and Albrecht, Dirk and Bongaerts, Johannes and Evers, Stefan and Hecker, Michael and Daniel, Rolf and Liesegang, Heiko}, title = {Fermentation stage-dependent adaptations of Bacillus licheniformis during enzyme production}, series = {Microbial Cell Factories}, volume = {12}, journal = {Microbial Cell Factories}, publisher = {Biomed Central}, address = {London}, issn = {1475-2859}, doi = {10.1186/1475-2859-12-120}, pages = {120}, year = {2013}, language = {en} } @inproceedings{TippkoetterRoikaewUlber2008, author = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland}, title = {An automated pilot plant for the bioengineering processing of concentrated whey}, series = {European BioPerspectives : in cooperation with BIOTECHNICA 2008 : 7 - 9 October 2008 Hannover, Germany ; book of abstracts ; abstracts, poster programme}, booktitle = {European BioPerspectives : in cooperation with BIOTECHNICA 2008 : 7 - 9 October 2008 Hannover, Germany ; book of abstracts ; abstracts, poster programme}, publisher = {Dechema}, address = {Frankfurt am Main}, pages = {98}, year = {2008}, language = {en} } @article{ZientzBongaertsUnden1998, author = {Zientz, Evelyn and Bongaerts, Johannes and Unden, Gottfried}, title = {Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system}, series = {Journal of bacteriology}, volume = {Vol. 180}, journal = {Journal of bacteriology}, number = {No. 20}, issn = {1098-5530 (E-Journal); 0021-9193 (Print)}, pages = {5421 -- 5425}, year = {1998}, language = {en} } @inproceedings{DeterdingTippkoetterUlber2006, author = {Deterding, A. and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Online-Essigs{\"a}ureanalytik in Fermentationsbr{\"u}hen mittels Fließdiffusionstechnik (FDT)}, series = {Technische Systeme f{\"u}r Biotechnologie und Umwelt : 13. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 25.09. - 27.09.2006}, booktitle = {Technische Systeme f{\"u}r Biotechnologie und Umwelt : 13. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 25.09. - 27.09.2006}, editor = {Beckmann, Dieter}, address = {Heiligenstadt}, organization = {Institut f{\"u}r Bioprozeß- und Analysenmeßtechnik}, isbn = {978-3-00-018621-9}, pages = {273 -- 280}, year = {2006}, language = {de} } @incollection{UlberMufflerTippkoetteretal.2011, author = {Ulber, Roland and Muffler, Kai and Tippk{\"o}tter, Nils and Hirth, Thomas and Sell, Dieter}, title = {Introduction to Renewable Resources in the Chemical Industry}, series = {Renewable raw materials : new feedstocks for the chemical industry}, booktitle = {Renewable raw materials : new feedstocks for the chemical industry}, editor = {Ulber, Roland and Sell, Dieter and Hirth, Thomas}, edition = {1. Auflage}, publisher = {Wiley-VCH-Verlag}, address = {Weinheim}, isbn = {978-3-527-32548-1}, pages = {1 -- 6}, year = {2011}, language = {de} } @article{WiesenTippkoetterMuffleretal.2014, author = {Wiesen, Sebastian and Tippk{\"o}tter, Nils and Muffler, Kai and Suck, Kirstin and Sohling, Ulrich and Ruf, Nils and Ulber, Roland}, title = {Adsorptive Vorbehandlung von Rohglycerin f{\"u}r die 1,3-Propandiol Fermentation mit Clostridium diolis}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {1-2}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201300080}, pages = {129 -- 135}, year = {2014}, abstract = {Bei der Gewinnung von Fetts{\"a}uren aus Pflanzen{\"o}len, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, f{\"a}llt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fetts{\"a}uren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fetts{\"a}uren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erh{\"o}hen.}, language = {de} }