TY - JOUR A1 - Deppe, Veronika Maria A1 - Klatte, Stephanie A1 - Bongaerts, Johannes A1 - Maurer, Karl-Heinz A1 - O'Connell, Timothy A1 - Meinhardt, Friedhelm T1 - Genetic control of Amadori product degradation in Bacillus subtilis via regulation of frlBONMD expression by FrlR JF - Applied and environmental microbiology Y1 - 2011 SN - 1098-5336 (E-Journal); 0003-6919 (Print); 0099-2240 (Print) VL - Vol. 77 IS - No. 9 SP - 2839 EP - 2846 PB - American Society of Mechanical Engineers (ASME) CY - New York ER - TY - JOUR A1 - Ulber, Roland A1 - Tippkötter, Nils A1 - Buchholz, H. A1 - Demmer, W. A1 - Scheper, T. T1 - Innovative Verfahren in der Molkeaufarbeitung zur Gewinnung neuer Produkte JF - Deutsche Milchwirtschaft Y1 - 2008 SN - 0012-0480 VL - 59 IS - 19 SP - 704 EP - 706 ER - TY - CHAP A1 - Frotscher, Ralf A1 - Goßmann, Matthias A1 - Raatschen, Hans-Jürgen A1 - Temiz Artmann, Aysegül A1 - Staat, Manfred T1 - Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM T2 - Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45) N2 - We present an electromechanically coupled Finite Element model for cardiac tissue. It bases on the mechanical model for cardiac tissue of Hunter et al. that we couple to the McAllister-Noble-Tsien electrophysiological model of purkinje fibre cells. The corresponding system of ordinary differential equations is implemented on the level of the constitutive equations in a geometrically and physically nonlinear version of the so-called edge-based smoothed FEM for plates. Mechanical material parameters are determined from our own pressure-deflection experimental setup. The main purpose of the model is to further examine the experimental results not only on mechanical but also on electrophysiological level down to ion channel gates. Moreover, we present first drug treatment simulations and validate the model with respect to the experiments. Y1 - 2015 SN - 978-3-319-02534-6 ; 978-3-319-02535-3 SP - 187 EP - 212 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Engel, M. A1 - Thieringer, J. A1 - Tippkötter, Nils T1 - Microbial electrosynthesis for sustainable biobutanol production T2 - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany Y1 - 2016 SP - 77 EP - 78 PB - DECHEMA CY - Frankfurt am Main ER - TY - JOUR A1 - Borgmeier, Claudia A1 - Bongaerts, Johannes A1 - Meinhardt, Friedhelm T1 - Genetic analysis of the Bacillus licheniformis degSU operon and the impact of regulatory mutations on protease production JF - Journal of biotechnology N2 - Disruption experiments targeted at the Bacillus licheniformis degSU operon and GFP-reporter analysis provided evidence for promoter activity immediately upstream of degU. pMutin mediated concomitant introduction of the degU32 allele – known to cause hypersecretion in Bacillus subtilis – resulted in a marked increase in protease activity. Application of 5-fluorouracil based counterselection through establishment of a phosphoribosyltransferase deficient Δupp strain eventually facilitated the marker-free introduction of degU32 leading to further protease enhancement achieving levels as for hypersecreting wild strains in which degU was overexpressed. Surprisingly, deletion of rapG – known to interfere with DegU DNA-binding in B. subtilis – did not enhance protease production neither in the wild type nor in the degU32 strain. The combination of degU32 and Δupp counterselection in the type strain is not only equally effective as in hypersecreting wild strains with respect to protease production but furthermore facilitates genetic strain improvement aiming at biological containment and effectiveness of biotechnological processes. KW - Marker-free mutagenesis KW - Extracellular enzymes KW - Uracil-phosphoribosyltransferase KW - Hypersecretion Y1 - 2012 U6 - https://doi.org/10.1016/j.jbiotec.2012.02.011 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 159 IS - 1-2 SP - 12 EP - 20 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Molinnus, Denise A1 - Sorich, Maren A1 - Bartz, Alexander A1 - Siegert, Petra A1 - Willenberg, Holger S. A1 - Lisdat, Fred A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate JF - Sensors and Actuators B: Chemical N2 - An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure. Y1 - 2016 U6 - https://doi.org/10.1016/j.snb.2016.06.064 SN - 0925-4005 VL - 237 SP - 190 EP - 195 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Beging, Stefan A1 - Biselli, Manfred A1 - Poghossian, Arshak A1 - Wang, J. A1 - Zang, Werner A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Concept for a solid-state multi-parameter sensor system for cell-culture monitoring JF - Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI Y1 - 2009 SN - 0013-4686 SP - 6107 EP - 6112 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Biselli, Manfred A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Schnitzler, Thomas A1 - Zang, Werner A1 - Wagner, P. T1 - Entwicklung eines modularen festkörperbasierten Sensorsystems für die Überwachung von Zellkulturfermenationen JF - Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vorträge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in Nürnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA) Y1 - 2010 SN - 978-3-8007-3260-9 N1 - Fachtagung Sensoren und Messsysteme 15, 2010, Nürnberg ; Gesellschaft Mess- und Automatisierungstechnik SP - 688 EP - 691 PB - VDE Verlag CY - Berlin ER - TY - CHAP A1 - Tippkötter, Nils A1 - Schünemann, V. A1 - Christmann, R. A1 - Pasteur, A. A1 - Schweizer, J. A1 - Ulber, Roland ED - Beckmann, Dieter T1 - Bioaffinity Layering magnetisierbarer Mikro- und Nanopartikel T2 - Technische Systeme für die Lebenswissenschaften : 14. Heiligenstädter Kolloquium, Heilbad Heiligenstadt, 22.09. - 24.09.2008 Y1 - 2008 SN - 978-3-00-025695-0 SP - 97 EP - 98 CY - Heiligenstadt ER - TY - JOUR A1 - Huck, Christina A1 - Schiffels, Johannes A1 - Herrera, Cony N. A1 - Schelden, Maximilian A1 - Selmer, Thorsten A1 - Poghossian, Arshak A1 - Baumann, Marcus A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor JF - Physica Status Solidi (A) N2 - Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the “welfare” of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis–Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed. Y1 - 2013 U6 - https://doi.org/10.1002/pssa.201200900 SN - 0031-8965 VL - 210 IS - 5 SP - 926 EP - 931 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Thiel, Alexander A1 - Tippkötter, Nils A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - New zeolite adsorbents for downstream processing of polyphenols from renewable resources JF - Engineering in Life Sciences N2 - Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources. Y1 - 2013 U6 - https://doi.org/10.1002/elsc.201200188 VL - 13 IS - 3 SP - 239 EP - 246 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Teumer, T. A1 - Capitain, C. A1 - Ross-Jones, J. A1 - Tippkötter, Nils A1 - Rädle, M. A1 - Methner, F.-J. T1 - In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor JF - BrewingScience N2 - 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. Y1 - 2018 SN - 1613-2041 VL - 71 IS - 5/6 SP - 49 EP - 55 PB - Fachverlag Hans Carl CY - Nürnberg ER - TY - RPRT A1 - Tippkötter, Nils A1 - Wagner, Sebastian T1 - Biomimetischer Klebstoff aus ligninhaltigen Pflanzenresten (Teilvorhaben 1 und 2) : Schlussbericht zum Vorhaben : Laufzeit: 01.01.2016 bis 31.03.2019 Y1 - 2019 U6 - https://doi.org/10.2314/KXP:169732777X N1 - Förderkennzeichen BMEL 22030514 - 22004615 PB - FH Aachen CY - Jülich ER - TY - JOUR A1 - Rösch, C. A1 - Kratz, F. A1 - Hering, T. A1 - Trautmann, S. A1 - Umanskaya, N. A1 - Tippkötter, Nils A1 - Müller-Renno, C.M. A1 - Ulber, Roland A1 - Hannig, M. A1 - Ziegler, C. T1 - Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity JF - Colloids and Surfaces B: Biointerfaces N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1016/j.colsurfb.2016.09.048 VL - 149 IS - 1 SP - 115 EP - 121 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Molinnus, Denise A1 - Bäcker, Matthias A1 - Siegert, Petra A1 - Willenberg, H. A1 - Poghossian, Arshak A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Detection of Adrenaline Based on Substrate Recycling Amplification JF - Procedia Engineering N2 - 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. Y1 - 2015 U6 - https://doi.org/10.1016/j.proeng.2015.08.708 SN - 1877-7058 N1 - Eurosensors 2015 VL - 120 SP - 540 EP - 543 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tippkötter, Nils A1 - Wollny, S. A1 - Kampeis, P. A1 - Oster, J. A1 - Schneider, H. A1 - Ulber, Roland T1 - Magnetseparation von Proteinen : Separation von Zielmolekülen durch hochselektive Aptamere JF - GIT Labor-Fachzeitschrift N2 - Durch die Kombination von Oligonukleotid-Liganden (Aptameren) hoher Bindungsaffinitäten mit hochselektiv abtrennbaren magnetisierbaren Mikropartikeln wird eine einstufige Separation von Zielmolekülen aus mikrobiologischen Produktionsansätzen möglich. Die Aptamere werden hierfür reversibel auf den Partikeloberflächen gebunden und für die spezifische Isolierung von Bioprodukten eingesetzt. Die Abtrennung der beladenen Partikel erfolgt durch einen neuen Rotor-Stator-Separator mit Hochgradient-Magnetfeld. Y1 - 2011 VL - 55 IS - 10 SP - 666 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Wagemann, Kurt A1 - Tippkötter, Nils T1 - Biorefineries: a short introduction T2 - Biorefineries N2 - 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. KW - Bioeconomy KW - Biorefinery definitions KW - Introduction KW - Process schemes KW - Renewable resources Y1 - 2018 SN - 978-3-319-97117-9 SN - 978-3-319-97119-3 U6 - https://doi.org/10.1007/10_2017_4 N1 - (Advances in Biochemical Engineering/Biotechnology book series ; Vol. 166) SP - 1 EP - 11 PB - Springer CY - Cham ER - TY - JOUR A1 - Wulfhorst, Helene A1 - Duwe, Anna-Maria A1 - Merseburg, Johannes A1 - Tippkötter, Nils T1 - Compositional analysis of pretreated (beech) wood using differential scanning calorimetry and multivariate data analysis JF - Tetrahedron N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1016/j.tet.2016.04.029 VL - 72 IS - 46 SP - 7329 EP - 7334 PB - Elsevier CY - Amsterdam ER - TY - RPRT A1 - Tippkötter, Nils T1 - Lokale Vorbehandlung nachwachsender Rohstoffe für Bioraffinerien (BioSats) : Schlussbericht zum Vorhaben : Laufzeit: 01.03.2012 bis 30.04.2017 Y1 - 2018 U6 - https://doi.org/10.2314/GBV:1024204243 ER - TY - JOUR A1 - Wackwitz, B. A1 - Bongaerts, Johannes A1 - Goodman, S. D. A1 - Unden, Gottfried T1 - Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significance JF - Molecular and general genetics : MGG Y1 - 1999 SN - 1617-4623 (E-Journal); 1617-4615 (Print) VL - Vol. 262 IS - Iss. 4 - 5 SP - 876 EP - 883 ER -