@article{WernerGroebelKrumbeetal.2012, author = {Werner, Frederik and Groebel, Simone and Krumbe, Christoph and Wagner, Torsten and Selmer, Thorsten and Yoshinobu, Tatsuo and Baumann, Marcus and Sch{\"o}ning, Michael Josef}, title = {Nutrient concentration-sensitive microorganism-based biosensor}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100801}, pages = {900 -- 904}, year = {2012}, language = {en} } @article{TakenagaBiselliSchnitzleretal.2014, author = {Takenaga, Shoko and Biselli, Manfred and Schnitzler, Thomas and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis-Menten-like kinetics for cell culturing}, series = {Physica status solidi A : Applications and materials science}, volume = {211}, journal = {Physica status solidi A : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330464}, pages = {1410 -- 1415}, year = {2014}, abstract = {The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17-200 mM) follows a Michaelis-Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Theoretical study and simulation of light-addressable potentiometric sensors}, series = {Physica status solidi (A) : applications and materials}, volume = {211}, journal = {Physica status solidi (A) : applications and materials}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201330354}, pages = {1467 -- 1472}, year = {2014}, abstract = {The light-addressable potentiometric sensor (LAPS) is a semiconductor-based potentiometric sensor using a light probe with an ability of detecting the concentration of biochemical species in a spatially resolved manner. As an important biomedical sensor, research has been conducted to improve its performance, for instance, to realize high-speed measurement. In this work, the idea of facilitating the device-level simulation, instead of using an equivalent-circuit model, is presented for detailed analysis and optimization of the performance of the LAPS. Both carrier distribution and photocurrent response have been simulated to provide new insight into both amplitude-mode and phase-mode operations of the LAPS. Various device parameters can be examined to effectively design and optimize the LAPS structures and setups for enhanced performance.}, language = {en} } @incollection{WendorffEggertPohletal.2007, author = {Wendorff, Marion and Eggert, Thorsten and Pohl, Martina and Dresen, Carola and M{\"u}ller, Michael and Jaeger, Karl-Erich and Sprenger, Georg A. and Sch{\"u}rmann, Melanie and Sch{\"u}rmann, Martin and Johnen, Sandra and Sprenger, Gerda and Sahm, Hermann and Inoue, Tomoyuki and Sch{\"o}rken, Ulrich and Breittaupt, Holger and Fr{\"o}lich, Bettina and Heim, Petra and Iding, Hans and Juchem, Bettina and Siegert, Petra and Kula, Maria-Regina and Weckbecker, Andrea and Hummel, Werner and Fessner, Wolf-Dieter and Elling, Lothar and Wolberg, Michael and Bode, Silke and Feldmann, Ralf and Geilenkirchen, Petra and Schubert, Thomas and Walter, Lydia and D{\"u}nnwald, Thomas and Demir, Ayhan S. and Kolter-Jung, Doris and Nitsche, Adam and D{\"u}nkelmann, Pascal and Cosp, Annabel and Lingen, Bettina}, title = {Catalytic asymmetric synthesis : section 2.2}, series = {Asymmetric synthesis with chemical and biological methods / ed. by Dieter Enders ...}, booktitle = {Asymmetric synthesis with chemical and biological methods / ed. by Dieter Enders ...}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-31473-7}, pages = {298 -- 413}, year = {2007}, language = {en} } @article{RaueWambachGloeggleretal.2014, author = {Raue, Markus and Wambach, M. and Gl{\"o}ggler, S. and Grefen, Dana and Kaufmann, R. and Abetz, C. and Georgopanos, P. and Handge, U. A. and Mang, Thomas and Bl{\"u}mich, B. and Abetz, V.}, title = {Investigation of historical hard rubber ornaments of Charles Goodyear}, series = {Macromolecular chemistry and physics}, volume = {Vol. 215}, journal = {Macromolecular chemistry and physics}, number = {No. 3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1022-1352}, pages = {245 -- 254}, year = {2014}, language = {en} } @article{BreuerRaueStrobeletal.2016, author = {Breuer, Lars and Raue, Markus and Strobel, M. and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, R. and Wagner, Torsten}, title = {Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems}, series = {Physica status solidi (a)}, volume = {213}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300}, doi = {10.1002/pssa.201533056}, pages = {1520 -- 1525}, year = {2016}, abstract = {Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.}, language = {en} } @article{AlKaidyTippkoetter2016, author = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils}, title = {Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase}, series = {Engineering in Life Sciences}, volume = {16}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/elsc.201400124}, pages = {222 -- 230}, year = {2016}, abstract = {In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1-30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established.}, language = {en} } @misc{TippkoetterUlber2009, author = {Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Eine magnetische horizontale Wirbelschicht f{\"u}r die Durchmischung und R{\"u}ckhaltung von magnetisierbaren Mikropartikeln im Durchfluss}, series = {Chemie Ingenieur Technik}, volume = {81}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.200950076}, pages = {1168}, year = {2009}, abstract = {Magnetisierbare Partikel als Tr{\"a}ger von Katalysatoren k{\"o}nnen durch Anlegen eines magnetisches Feldes einfach und schnell abgetrennt werden. Die Wiedergewinnung von wertvollen Enzymen unter geringem Energie- und Materialeinsatz der magnetischen Abtrennung er{\"o}ffnet einen Wettbewerbsvorteil f{\"u}r Produktionsprozesse. Die Abtrennung von magnetisierbaren Partikeln vom {\"U}berstand wird {\"u}blicherweise entweder durch Anlegen eines {\"a}ußeren Magnetfelds und der resultierenden Ablagerung der Partikel an den Reaktorw{\"a}nden oder durch Hochgradientenmagnetseparation (HGMS)durchgef{\"u}hrt. Beide Verfahren resultieren meist in der Bildung eines Filterkuchens aus Magnetpartikeln und den Feststoffen des Reaktionsmediums. Das magnetische horizontale Wirbelbett erm{\"o}glicht simultan eine kontinuierliche Reaktionsf{\"u}hrung und die R{\"u}ckhaltung der Partikel im Durchfluss. Die Partikelsuspension fließt durch einen Rohrreaktor, der in einem Magnetfeld mit wechselnden Feldgradienten eingebracht ist. Die {\"A}nderung des Magnetfeldgradienten erfolgt entgegen der Str{\"o}mungsrichtung der Reaktionsl{\"o}sung. Durch alternierende Feldmaxima an den beiden Seiten des Reaktors werden die magnetisierbaren Partikel zu dessen W{\"a}nden gezogen. Bei Umkehrung des Feldes wandern die Partikel an die gegen{\"u}berliegende Reaktorwand. Durch Wahl einer geeigneten Wechselfrequenz kann eine kontinuierliche Durchmischung und R{\"u}ckhaltung der Mikropartikel im durchstr{\"o}mten Rohr erreicht werden. Somit k{\"o}nnen Immobilisierungsreaktionen und Biotransformationen mit den Partikelsystemen im Durchfluss durchgef{\"u}hrt werden.}, language = {en} } @article{SiekerNeunerDimitrovaetal.2010, author = {Sieker, Tim and Neuner, Andreas and Dimitrova, Darina and Tippk{\"o}tter, Nils and Bart, Hans-J{\"o}rg and Heinzle, Elmar and Ulber, Roland}, title = {Grassilage als Rohstoff f{\"u}r die chemische Industrie}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {8, Special Issue: Industrielle Nutzung nachwachsender Rohstoffe}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1522-2640}, doi = {10.1002/cite.201000088}, pages = {1153 -- 1159}, year = {2010}, abstract = {Grassilage stellt einen nachwachsenden Rohstoff mit großem Potenzial dar. Neben Cellulose und Hemicellulose enth{\"a}lt sie auch organische S{\"a}uren, insbesondere Milchs{\"a}ure. In einem Bioraffinerie-Projekt wird die Milchs{\"a}ure aus der Silage isoliert und mit gentechnisch optimierten St{\"a}mmen 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 s{\"a}mtliche Inhaltsstoffe der Silage verwertet.}, language = {de} } @misc{TippkoetterSiekerWiesenetal.2014, author = {Tippk{\"o}tter, Nils and Sieker, T. and Wiesen, S. and Duwe, A. and Roth, J. and Ulber, Roland}, title = {Simultane Saccharifizierung und Fermentierung (SSF) sowie Produktion von Aceton, Butanol, Ethanol (ABE) und Dicarbons{\"a}uren aus technischer Cellulose}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450297}, pages = {1518}, year = {2014}, abstract = {Technische Cellulose wurde als m{\"o}glicher Rohstoff zur fermentativen Produktbildung untersucht. Hierf{\"u}r wird Cellulose in der Lignocellulose-Bioraffinerie hergestellt und daraus Hydrolysat gewonnen. Die Pr{\"u}fung der technischen Hydrolysate als Substrate erfolgte anhand eines breiten Spektrums an Bioprodukten, von Kraftstoffen wie Ethanolund Butanol, bis zu den Dicarbons{\"a}uren Itacon- und Bernsteins{\"a}ure. 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) durchgef{\"u}hrt werden. Aufgrund der Produkttoxizit{\"a}t erfordert die Butanol-Herstellung dabei eine In-situ-Produktabtrennung durch L{\"o}semittelimpr{\"a}gnierte Partikel. Die Herstellung der beiden Dicarbons{\"a}uren unterscheidet sich in der Sensitivit{\"a}t der verwendeten Mikroorganismen gegen{\"u}ber Inhibitoren, die in Spuren im Hydrolysat enthalten sind. Die Bernteins{\"a}urebildung mit Actinobacillussuccinogenes kann mit unbehandeltem Hydrolysat erfolgen. Dagegen erfordert die Gewinnung von Itacons{\"a}ure mit A. terreus eine Detoxifizierung des Hydrolysats. Insgesamt konnte gezeigt werden, dass s{\"a}mtliche Bioraffinerie-Hydrolysate als Substrate f{\"u}r unterschiedliche Fermentationen geeignet sind.}, language = {de} }