@article{UlberTippkoetterBuchholzetal.2008, author = {Ulber, Roland and Tippk{\"o}tter, Nils and Buchholz, H. and Demmer, W. and Scheper, T.}, title = {Innovative Verfahren in der Molkeaufarbeitung zur Gewinnung neuer Produkte}, series = {Deutsche Milchwirtschaft}, volume = {59}, journal = {Deutsche Milchwirtschaft}, number = {19}, issn = {0012-0480}, pages = {704 -- 706}, year = {2008}, language = {de} } @incollection{FrotscherGossmannRaatschenetal.2015, author = {Frotscher, Ralf and Goßmann, Matthias and Raatschen, Hans-J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Staat, Manfred}, title = {Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM}, series = {Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45)}, booktitle = {Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45)}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-319-02534-6 ; 978-3-319-02535-3}, pages = {187 -- 212}, year = {2015}, abstract = {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.}, language = {en} } @inproceedings{EngelThieringerTippkoetter2016, author = {Engel, M. and Thieringer, J. and Tippk{\"o}tter, Nils}, title = {Microbial electrosynthesis for sustainable biobutanol production}, series = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany}, booktitle = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany}, publisher = {DECHEMA}, address = {Frankfurt am Main}, pages = {77 -- 78}, year = {2016}, language = {en} } @article{BorgmeierBongaertsMeinhardt2012, author = {Borgmeier, Claudia and Bongaerts, Johannes and Meinhardt, Friedhelm}, title = {Genetic analysis of the Bacillus licheniformis degSU operon and the impact of regulatory mutations on protease production}, series = {Journal of biotechnology}, volume = {159}, journal = {Journal of biotechnology}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2012.02.011}, pages = {12 -- 20}, year = {2012}, abstract = {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.}, language = {en} } @article{MolinnusSorichBartzetal.2016, author = {Molinnus, Denise and Sorich, Maren and Bartz, Alexander and Siegert, Petra and Willenberg, Holger S. and Lisdat, Fred and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate}, series = {Sensors and Actuators B: Chemical}, volume = {237}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.06.064}, pages = {190 -- 195}, year = {2016}, abstract = {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.}, language = {en} } @article{BaeckerBegingBisellietal.2009, author = {B{\"a}cker, Matthias and Beging, Stefan and Biselli, Manfred and Poghossian, Arshak and Wang, J. and Zang, Werner and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Concept for a solid-state multi-parameter sensor system for cell-culture monitoring}, series = {Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI}, journal = {Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0013-4686}, pages = {6107 -- 6112}, year = {2009}, language = {en} } @article{BiselliBaeckerPoghossianetal.2010, author = {Biselli, Manfred and B{\"a}cker, Matthias and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Schnitzler, Thomas and Zang, Werner and Wagner, P.}, title = {Entwicklung eines modularen festk{\"o}rperbasierten Sensorsystems f{\"u}r die {\"U}berwachung von Zellkulturfermenationen}, series = {Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vortr{\"a}ge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in N{\"u}rnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA)}, journal = {Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vortr{\"a}ge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in N{\"u}rnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA)}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-3260-9}, pages = {688 -- 691}, year = {2010}, language = {de} } @inproceedings{TippkoetterSchuenemannChristmannetal.2008, author = {Tippk{\"o}tter, Nils and Sch{\"u}nemann, V. and Christmann, R. and Pasteur, A. and Schweizer, J. and Ulber, Roland}, title = {Bioaffinity Layering magnetisierbarer Mikro- und Nanopartikel}, series = {Technische Systeme f{\"u}r die Lebenswissenschaften : 14. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 22.09. - 24.09.2008}, booktitle = {Technische Systeme f{\"u}r die Lebenswissenschaften : 14. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 22.09. - 24.09.2008}, editor = {Beckmann, Dieter}, address = {Heiligenstadt}, isbn = {978-3-00-025695-0}, pages = {97 -- 98}, year = {2008}, language = {de} } @article{HuckSchiffelsHerreraetal.2013, author = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201200900}, pages = {926 -- 931}, year = {2013}, abstract = {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.}, language = {en} } @article{ThielTippkoetterSucketal.2013, author = {Thiel, Alexander and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland}, title = {New zeolite adsorbents for downstream processing of polyphenols from renewable resources}, series = {Engineering in Life Sciences}, volume = {13}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/elsc.201200188}, pages = {239 -- 246}, year = {2013}, abstract = {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.}, language = {en} }