TY  - JOUR
A1  - Arreola, Julio
A1  - Mätzkow, Malte
A1  - Durán, Marlena Palomar
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of the immobilization of bacterial spores on glass substrates with organosilanes
JF  - Physica status solidi (A) : Applications and materials science
N2  - Spores can be immobilized on biosensors to function as sensitive recognition elements. However, the immobilization can affect the sensitivity and reproducibility of the sensor signal. In this work, three different immobilization strategies with organosilanes were optimized and characterized to immobilize Bacillus atrophaeus spores on glass substrates. Five different silanization parameters were investigated: nature of the solvent, concentration of the silane, silanization time, curing process, and silanization temperature. The resulting silane layers were resistant to a buffer solution (e.g., Ringer solution) with a polysorbate (e.g., Tween®80) and sonication.
KW  - silanization
KW  - organosilanes
KW  - immobilization
KW  - endospores
KW  - biosensors
KW  - Bacillus atrophaeus
Y1  - 2016
U6  - http://dx.doi.org/10.1002/pssa.201532914
SN  - 1862-6319
VL  - 213
IS  - 6
SP  - 1463
EP  - 1470
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Degering, Christian
A1  - Eggert, Thorsten
A1  - Puls, Michael
A1  - Bongaerts, Johannes
A1  - Evers, Stefan
A1  - Maurer, Karl-Heinz
A1  - Jaeger, Karl-Erich
T1  - Optimization of protease secretion in Bacillus subtilis and Bacillus licheniformis by screening of homologous and herologous signal peptides
JF  - Applied and environmental microbiology
N2  - Bacillus subtilis and Bacillus licheniformis are widely used for the large-scale industrial production of proteins. These strains can efficiently secrete proteins into the culture medium using the general secretion (Sec) pathway. A characteristic feature of all secreted proteins is their N-terminal signal peptides, which are recognized by the secretion machinery. Here, we have studied the production of an industrially important secreted protease, namely, subtilisin BPN′ from Bacillus amyloliquefaciens. One hundred seventy-three signal peptides originating from B. subtilis and 220 signal peptides from the B. licheniformis type strain were fused to this secretion target and expressed in B. subtilis, and the resulting library was analyzed by high-throughput screening for extracellular proteolytic activity. We have identified a number of signal peptides originating from both organisms which produced significantly increased yield of the secreted protease. Interestingly, we observed that levels of extracellular protease were improved not only in B. subtilis, which was used as the screening host, but also in two different B. licheniformis strains. To date, it is impossible to predict which signal peptide will result in better secretion and thus an improved yield of a given extracellular target protein. Our data show that screening a library consisting of homologous and heterologous signal peptides fused to a target protein can identify more-effective signal peptides, resulting in improved protein export not only in the original screening host but also in different production strains.
Y1  - 2010
U6  - http://dx.doi.org/10.1128/AEM.01146-10
SN  - 1098-5336 (E-Journal); 0003-6919 (Print); 0099-2240 (Print)
VL  - 76
IS  - 19
SP  - 6370
EP  - 6378
PB  - American Society for Microbiology
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Faßbender, F.
A1  - Schmitt, G.
A1  - Schöning, Michael Josef
A1  - Lüth, H.
A1  - Buß, G.
A1  - Schultze, J. W.
T1  - Optimization of passivation layers for corrosion protection of silicon-based microelectrode arrays
JF  - Sensors and Actuators B. 68 (2000), H. 1-3
Y1  - 2000
SN  - 0925-4005
SP  - 128
EP  - 133
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Röhlen, Desiree
A1  - Wagner, Torsten
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Optimization of Cell-Based Multi-Chamber LAPS Measurements Utilizing FPGA-Controlled Laser-Diode Modules
JF  - physica status solidi a : applications and materials sciences
N2  - A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric device, which detects concentration changes of an analyte solution on the sensor surface in a spatially resolved way. It uses a light source to generate electron–hole pairs inside the semiconductor, which are separated in the depletion region due to an applied bias voltage across the sensor structure and hence, a surface-potential-dependent photocurrent can be read out. However, depending on the beam angle of the light source, scattering effects can occur, which influence the recorded signal in LAPS-based differential measurements. To solve this problem, a novel illumination unit based on a field programmable gate array (FPGA) consisting of 16 small-sized tunable infrared laser-diode modules (LDMs) is developed. Due to the improved focus of the LDMs with a beam angle of only 2 mrad, undesirable scattering effects are minimized. Escherichia coli (E. coli) K12 bacteria are used as a test microorganism to study the extracellular acidification on the sensor surface. Furthermore, a salt bridge chamber is built up and integrated with the LAPS system enabling multi-chamber differential measurements with a single Ag/AgCl reference electrode.
Y1  - 2018
U6  - http://dx.doi.org/10.1002/pssa.201800058
SN  - 1862-6319
VL  - 215
IS  - 15
SP  - Article number 1800058
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Mariano, K.
A1  - Keusgen, M.
A1  - Selmer, Thorsten
A1  - Schöning, Michael Josef
T1  - Optimization of an Enzyme-based Multi-parameter Biosensor for Monitoring Biogas Processes
JF  - Procedia Engineering
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.proeng.2015.08.702
SN  - 1877-7058
N1  - Part of special issue "Eurosensors 2015"
VL  - 120
SP  - 532
EP  - 535
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Yazici, Yasemen
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of an amperometric biosensor array for simultaneous measurement of ethanol, formate, d- and l-lactate
JF  - Electrochimica Acta
N2  - The immobilization of NAD+-dependent dehydrogenases, in combination with a diaphorase, enables the facile development of multiparametric sensing devices. In this work, an amperometric biosensor array for simultaneous determination of ethanol, formate, d- and l-lactate is presented. Enzyme immobilization on platinum thin-film electrodes was realized by chemical cross-linking with glutaraldehyde. The optimization of the sensor performance was investigated with regard to enzyme loading, glutaraldehyde concentration, pH, cofactor concentration and temperature. Under optimal working conditions (potassium phosphate buffer with pH 7.5, 2.5 mmol L-1 NAD+, 2.0 mmol L-1 ferricyanide, 25 °C and 0.4% glutaraldehyde) the linear working range and sensitivity of the four sensor elements was improved. Simultaneous and cross-talk free measurements of four different metabolic parameters were performed successfully. The reliable analytical performance of the biosensor array was demonstrated by application in a clarified sample of inoculum sludge. Thereby, a promising approach for on-site monitoring of fermentation processes is provided.
KW  - Simultaneous determination
KW  - Enzymatic biosensor
KW  - Diaphorase
KW  - Dehydrogenase
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.electacta.2017.07.119
SN  - 0013-4686
VL  - 251
SP  - 256
EP  - 262
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kirchner, Patrick
A1  - Oberländer, Jan
A1  - Friedrich, Peter
A1  - Berger, Jörg
A1  - Suso, Henri-Pierre
A1  - Kupyna, Andriy
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimisation and fabrication of a calorimetric gas sensor built up on a polyimide substrate for H2O2 monitoring
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1235
EP  - 1240
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Beging, Stefan
A1  - Rotter, L.
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Zang, Werner
A1  - Schöning, Michael Josef
T1  - Online-Messsysteme für die automatisierte Charakterisierung von feldeffektbasierten Biosensoren
JF  - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)
Y1  - 2007
SN  - 978-3-940046-45-1
N1  - Dresdner Sensor-Symposium <8, 2007, Dresden> ; Dresdner Beiträge zur Sensorik ; 29
SP  - 257
EP  - 260
PB  - TUDpress, Verl. der Wissenschaften
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Zatko, B.
A1  - Dubecký, F.
A1  - Bohacek, P.
A1  - Gombia, E.
A1  - Frigeri, P.
A1  - Mosca, R.
A1  - Franchi, S.
A1  - Huarn, J.
A1  - Nescas, V.
A1  - Sekacova, M.
A1  - Förster, Arnold
A1  - Kordos, P.
T1  - On the spectrometric performance limit of radiation detectors based on semi-insulating GaAs
JF  - Nuclear instruments and methods in physics research, Section A. 531 (2004), H. 1-2
Y1  - 2004
SN  - 0168-9002
SP  - 111
EP  - 120
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Groebel, Simone
A1  - Krumbe, Christoph
A1  - Wagner, Torsten
A1  - Selmer, Thorsten
A1  - Yoshinobu, Tatsuo
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Nutrient concentration-sensitive microorganism-based biosensor
JF  - Physica Status Solidi (a)
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100801
SN  - 1862-6319
VL  - 209
IS  - 5
SP  - 900
EP  - 904
PB  - Wiley-VCH
CY  - Weinheim
ER  -