@article{RibitschKarlBirnerGruenbergeretal.2010, author = {Ribitsch, D. and Karl, W. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Wieland, S. and Siegert, Petra and Maurer, Karl-Heinz and Schwab, H.}, title = {C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli}, series = {Journal of biotechnology}, volume = {150}, journal = {Journal of biotechnology}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2010.09.947}, pages = {408 -- 416}, year = {2010}, abstract = {Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477. This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7-11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease.}, language = {en} } @article{ReisertHenkelSchneideretal.2009, author = {Reisert, Steffen and Henkel, H. and Schneider, A. and Sch{\"a}fer, Daniel and Friedrich, P. and Berger, J{\"o}rg and Sch{\"o}ning, Michael Josef}, title = {Entwicklung eines Handheld-Sensorsystems f{\"u}r die „On-line"-Messung der H2O2-Konzentration in aseptischen Entkeimungsprozessen}, series = {9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]}, journal = {9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]}, publisher = {TUDpress}, address = {Dresden}, isbn = {978-3-941298-44-6}, pages = {285 -- 288}, year = {2009}, language = {de} } @article{RibitschHeumannKarletal.2012, author = {Ribitsch, D. and Heumann, S. and Karl, W. and Gerlach, J. and Leber, R. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Siegert, Petra and Lange, J. and Maurer, Karl-Heinz and Berg, G. and Guebitz, G. M. and Schwab, H.}, title = {Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli}, series = {Journal of biotechnology}, volume = {157}, journal = {Journal of biotechnology}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2011.09.025}, pages = {140 -- 147}, year = {2012}, abstract = {A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2.}, language = {en} } @incollection{PoghossianSchusserBaeckeretal.2015, author = {Poghossian, Arshak and Schusser, Sebastian and B{\"a}cker, Matthias and Leinhos, Marcel and Sch{\"o}ning, Michael Josef}, title = {Real-time in-situ electrical monitoring of the degradation of biopolymers using semiconductor field-effect devices}, series = {Biodegradable biopolymers. Vol. 1}, booktitle = {Biodegradable biopolymers. Vol. 1}, publisher = {Nova Science Publ.}, address = {Hauppauge}, isbn = {978-1-63483-632-6}, pages = {135 -- 153}, year = {2015}, language = {en} } @inproceedings{BegingPoghossianMlyneketal.2010, author = {Beging, Stefan and Poghossian, Arshak and Mlynek, D. and Hataihimakul, S. and Pedraza, A. and Dhawan, S. and Laube, N. and Kleinen, Lisa and Baldsiefen, Gerhard and Busch, Heinrich von and Sch{\"o}ning, Michael Josef}, title = {Ion-selective sensors for the determination of the risk of urinary stone formation}, series = {Micro- and Nanosystems in biochemical diagnosis : Principles and applications}, booktitle = {Micro- and Nanosystems in biochemical diagnosis : Principles and applications}, address = {Warsaw}, pages = {74 -- 80}, year = {2010}, language = {en} } @article{BegingPoghossianSchoeningetal.2008, author = {Beging, Stefan and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Hataihimakul, Sudkanung and Busch, Heinz and Baldsiefen, Gerhard and Laube, N. and Kleinen, Lisa and Hosseiny, Reyhaneh}, title = {Feldeffektbasierender Ca2+-sensitiver Sensor f{\"u}r den Einsatz im Nativurin zur Bestimmung des Harnsteinbildungsrisikos}, series = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, journal = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092011-5}, pages = {775 -- 782}, year = {2008}, language = {de} } @article{MiyamotoKanekoMatsuoetal.2010, author = {Miyamoto, Ko-ichiro and Kaneko, Kazumi and Matsuo, Akira and Wagner, Torsten and Kanoh, Shin`ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Miniaturized chemical imaging sensor system using an OLED display panel}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2010.09.160}, pages = {516 -- 519}, year = {2010}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the currentvoltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.}, language = {en} } @article{PoghossianWagnerSchoening2010, author = {Poghossian, Arshak and Wagner, Holger and Sch{\"o}ning, Michael Josef}, title = {Automatisiertes „wafer level"-Testsystem zur Charakterisierung von siliziumbasierten Chemo- und Biosensoren}, series = {Tagungsband: Sensoren und Messsysteme 2010}, journal = {Tagungsband: Sensoren und Messsysteme 2010}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-3260-9}, pages = {89 -- 92}, year = {2010}, abstract = {Es wurde ein automatisiertes, computerunterst{\"u}tztes Testsystem f{\"u}r die Funktionspr{\"u}fung und Charakterisierung von (bio-)chemischen Sensoren auf Waferebene entwickelt und in einen konventionellen Spitzenmessplatz integriert. Das System erm{\"o}glicht die Charakterisierung und Identifizierung „funktionstauglicher" Sensoren bereits auf Waferebene zwischen den einzelnen Herstellungsschritten, wodurch weitere, bisher {\"u}bliche Verarbeitungsschritte wie das Fixieren, Bonden und Verkapseln f{\"u}r die defekten oder nicht funktionstauglichen Sensorstrukturen entf{\"a}llt. Außerdem bietet eine speziell entworfene miniaturisierte Durchflussmesszelle die M{\"o}glichkeit, bereits auf Waferlevel die Sensitivit{\"a}t, Drift, Hysterese und Ansprechzeit der (bio-)chemischen Sensoren zu charakterisieren. Das System wurde exemplarisch mit kapazitiven, pH-sensitiven EIS- (Elektrolyt-Isolator-Silizium) Strukturen und ISFET- (ionensensitiver Feldeffekttransistor) Strukturen mit verschiedenen Geometrien und Gate-Layouts getestet.}, language = {de} } @article{KirchnerOberlaenderFriedrichetal.2010, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Rysstad, Gunnar and Berger, J{\"o}rg and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2010.09.098}, pages = {264 -- 267}, year = {2010}, abstract = {A calorimetric gas sensor is presented for the monitoring of gas-phase H2O2 at elevated temperature during sterilization processes in aseptic food industry. The sensor consists of two temperature-sensitive thin-film resistances built up on a polyimide foil with a thickness of 25 μm, which are passivated with a layer of SU-8 photo resist and catalytically activated with manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilizes the elevated temperature of an evaporated H2O2 aerosol. In an experimental set-up, the sensor has shown a sensitivity of 4.78 °C/(\%v/v) in a H2O2 concentration range of 0 to 10\% v/v at an evaporation temperature of 240 ∘C. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied evaporation temperatures of the gas stream. The sensor characterization demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of sterilization processes.}, language = {en} } @article{BohrnStuetzFleischeretal.2010, author = {Bohrn, Ulrich and St{\"u}tz, Evamaria and Fleischer, Maximilian and Sch{\"o}ning, Michael Josef}, title = {Real-time detection of CO by eukaryotic cells}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, pages = {17 -- 20}, year = {2010}, abstract = {In this contribution, we focus on the detection of toxic gases with living eukaryotic cells. A cell-based gas sensor system, able to measure the effects of direct exposure of gases to cells in real-time, was set up. Impedance data as well as oxygen consumption of Chinese hamster lung fibroblast cells (V79) were analysed upon exposure to carbon monoxide (CO). The CO (diluted in wet synthetic air) affects the cell respiration as indicated by an attenuated respiration signal after the CO exposure as well as an instant increase of the capacitive part of the impedance signal during the gas exposure.}, language = {en} }