@article{MuschallikMolinnusBongaertsetal.2017,
  author    = {Muschallik, Lukas and Molinnus, Denise and Bongaerts, Johannes and Pohl, Martina and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Siegert, Petra and Selmer, Thorsten},
  title     = {(R,R)-Butane-2,3-diol Dehydrogenase from Bacillus clausii DSM 8716T: Cloning and Expression of the bdhA-Gene, and Initial Characterization of Enzyme},
  series = {Journal of Biotechnology},
  volume    = {258},
  journal   = {Journal of Biotechnology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0168-1656},
  doi       = {10.1016/j.jbiotec.2017.07.020},
  pages     = {41 -- 50},
  year      = {2017},
  abstract  = {The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716T was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33-43\%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12 U/mg and 23 U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115 U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74 U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD+ was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development.},
  language  = {en}
}
@article{HaegerBongaertsSiegert2022,
  author    = {Haeger, Gerrit and Bongaerts, Johannes and Siegert, Petra},
  title     = {A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent},
  series = {Analytical Biochemistry},
  journal   = {Analytical Biochemistry},
  number    = {624},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1096-0309},
  doi       = {10.1016/j.ab.2022.114819},
  pages     = {Artikel 114819},
  year      = {2022},
  abstract  = {An improved and convenient ninhydrin assay for aminoacylase activity measurements was developed using the commercial EZ Nin™ reagent. Alternative reagents from literature were also evaluated and compared. The addition of DMSO to the reagent enhanced the solubility of Ruhemann's purple (RP). Furthermore, we found that the use of a basic, aqueous buffer enhances stability of RP. An acidic protocol for the quantification of lysine was developed by addition of glacial acetic acid. The assay allows for parallel processing in a 96-well format with measurements microtiter plates.},
  language  = {en}
}
@article{PohlSiegertMeschetal.1998,
  author    = {Pohl, Martina and Siegert, Petra and Mesch, K. and Bruhn, H. and Gr{\"o}tzinger, Joachim},
  title     = {Active site mutants of pyruvate decarboxylase from Zymomonas mobilis : a site-directed mutagenesis study of L112, I472, I476, E473 and N482},
  series = {European journal of biochemistry},
  volume    = {Vol. 257},
  journal   = {European journal of biochemistry},
  number    = {Iss. 3},
  issn      = {1432-1033 (E-Journal); 1742-4658 (E-Journal); 0014-2956 (Print); 1742-464X (Print)},
  pages     = {538 -- 546},
  year      = {1998},
  language  = {en}
}
@article{IdingSiegertMeschetal.1998,
  author    = {Iding, Hans and Siegert, Petra and Mesch, K. and Pohl, Martina},
  title     = {Application of α-keto acid decarboxylases in biotransformations},
  series = {Biochimica et biophysica acta (BBA) - Protein structure and molecular enzymology},
  volume    = {Vol. 1385},
  journal   = {Biochimica et biophysica acta (BBA) - Protein structure and molecular enzymology},
  number    = {Iss. 2},
  issn      = {1879-2588 (E-Journal); 0167-4838 (Print)},
  pages     = {307 -- 322},
  year      = {1998},
  language  = {en}
}
@article{IdingDuennwaldGreineretal.2000,
  author    = {Iding, Hans and D{\"u}nnwald, Thomas and Greiner, Lasse and Liese, Andreas and M{\"u}ller, Michael and Siegert, Petra and Gr{\"o}tzinger, Joachim and Demir, Ayhan S. and Pohl, Martina},
  title     = {Benzoylformate Decarboxylase from Pseudomonas putida as Stable Catalyst for the Synthesis of Chiral 2-Hydroxy Ketones},
  series = {Chemistry - a European journal},
  volume    = {Vol. 6},
  journal   = {Chemistry - a European journal},
  number    = {Iss. 8},
  issn      = {1521-3765 (E-Journal); 0947-6539 (Print)},
  pages     = {1483 -- 1495},
  year      = {2000},
  language  = {en}
}
@inproceedings{SiegertIdingBaumannetal.2000,
  author    = {Siegert, Petra and Iding, Hans and Baumann, Martin and McLeish, Michael J. and Kenyon, George L. and Pohl, Martina},
  title     = {Broadening of the substrate spectra of two ThDP-dependent decarboxylases using site-directed-mutagenesis},
  series = {Proceedings of the 4th International Congress on Biochemical Engineering : 17 and 18 February 2000, Stuttgart},
  booktitle = {Proceedings of the 4th International Congress on Biochemical Engineering : 17 and 18 February 2000, Stuttgart},
  organization    = {International Congress on Biochemical Engineering <4, 2000, Stuttgart>},
  isbn      = {3-8167-5570-4},
  pages     = {38 -- 42},
  year      = {2000},
  language  = {en}
}
@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}
}
@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{DuennwaldDemirSiegertetal.2001,
  author    = {D{\"u}nnwald, Thomas and Demir, Ayhan S. and Siegert, Petra and Pohl, Martina and M{\"u}ller, Michael},
  title     = {ChemInform Abstract: Enantioselective synthesis of (S)-2-Hydroxypropanone derivatives by Benzoylformate Decarboxylase Catalyzed C—C Bond Formation},
  series = {Cheminform},
  volume    = {Vol. 32},
  journal   = {Cheminform},
  number    = {Iss. 4},
  issn      = {1522-2667 (E-Journal); 0931-7597 (Print)},
  pages     = {Publ. online},
  year      = {2001},
  language  = {en}
}
@article{WeldenSeverinsPoghossianetal.2022,
  author    = {Welden, Melanie and Severins, Robin and Poghossian, Arshak and Wege, Christina and Bongaerts, Johannes and Siegert, Petra and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor},
  series = {Chemosensors},
  volume    = {10},
  journal   = {Chemosensors},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2227-9040},
  doi       = {10.3390/chemosensors10060218},
  pages     = {Artikel 218},
  year      = {2022},
  abstract  = {Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte-insulator-semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716ᵀ is immobilized via biotin-streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage-current, capacitance-voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution.},
  language  = {en}
}
@article{MolinnusBaeckerSiegertetal.2015,
  author    = {Molinnus, Denise and B{\"a}cker, Matthias and Siegert, Petra and Willenberg, H. and Poghossian, Arshak and Keusgen, M. and Sch{\"o}ning, Michael Josef},
  title     = {Detection of Adrenaline Based on Substrate Recycling Amplification},
  series = {Procedia Engineering},
  volume    = {120},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2015.08.708},
  pages     = {540 -- 543},
  year      = {2015},
  abstract  = {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.},
  language  = {en}
}
@article{MolinnusHardtSiegertetal.2018,
  author    = {Molinnus, Denise and Hardt, Gabriel and Siegert, Petra and Willenberg, Holger S. and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Detection of Adrenaline in Blood Plasma as Biomarker for Adrenal Venous Sampling},
  series = {Electroanalysis},
  volume    = {30},
  journal   = {Electroanalysis},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1521-4109},
  doi       = {10.1002/elan.201800026},
  pages     = {937 -- 942},
  year      = {2018},
  abstract  = {An amperometric bi-enzyme biosensor based on substrate recycling principle for the amplification of the sensor signal has been developed for the detection of adrenaline in blood. Adrenaline can be used as biomarker verifying successful adrenal venous sampling procedure. The adrenaline biosensor has been realized via modification of a galvanic oxygen sensor with a bi-enzyme membrane combining a genetically modified laccase and a pyrroloquinoline quinone-dependent glucose dehydrogenase. The measurement conditions such as pH value and temperature were optimized to enhance the sensor performance. A high sensitivity and a low detection limit of about 0.5-1 nM adrenaline have been achieved in phosphate buffer at pH 7.4, relevant for measurements in blood samples. The sensitivity of the biosensor to other catecholamines such as noradrenaline, dopamine and dobutamine has been studied. Finally, the sensor has been successfully applied for the detection of adrenaline in human blood plasma.},
  language  = {en}
}
@article{MolinnusMuschallikGonzalezetal.2018,
  author    = {Molinnus, Denise and Muschallik, Lukas and Gonzalez, Laura Osorio and Bongaerts, Johannes and Wagner, Torsten and Selmer, Thorsten and Siegert, Petra and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Development and characterization of a field-effect biosensor for the detection of acetoin},
  series = {Biosensors and Bioelectronics},
  volume    = {115},
  journal   = {Biosensors and Bioelectronics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.bios.2018.05.023},
  pages     = {1 -- 6},
  year      = {2018},
  abstract  = {A capacitive electrolyte-insulator-semiconductor (EIS) field-effect biosensor for acetoin detection has been presented for the first time. The EIS sensor consists of a layer structure of Al/p-Si/SiO₂/Ta₂O₅/enzyme acetoin reductase. The enzyme, also referred to as butane-2,3-diol dehydrogenase from B. clausii DSM 8716T, has been recently characterized. The enzyme catalyzes the (R)-specific reduction of racemic acetoin to (R,R)- and meso-butane-2,3-diol, respectively. Two different enzyme immobilization strategies (cross-linking by using glutaraldehyde and adsorption) have been studied. Typical biosensor parameters such as optimal pH working range, sensitivity, hysteresis, linear concentration range and long-term stability have been examined by means of constant-capacitance (ConCap) mode measurements. Furthermore, preliminary experiments have been successfully carried out for the detection of acetoin in diluted white wine samples.},
  language  = {en}
}
@article{DuenkelmannKolterJungNitscheetal.2002,
  author    = {D{\"u}nkelmann, Pascal and Kolter-Jung, Doris and Nitsche, Adam and Demir, Ayhan S. and Siegert, Petra and Lingen, Bettina and Baumann, Martin and Pohl, Martina and M{\"u}ller, Michael},
  title     = {Development of a donor-acceptor concept for enzymatic cross-coupling reactions of adehydes : the first asymmetric cross-benzoin condensation},
  series = {Journal of the American Chemical Society},
  volume    = {Vol. 124},
  journal   = {Journal of the American Chemical Society},
  issn      = {1520-5126 (E-Journal); 0002-7863 (Print)},
  pages     = {12084 -- 12085},
  year      = {2002},
  language  = {en}
}
@article{DuennwaldDemirSiegertetal.2000,
  author    = {D{\"u}nnwald, Thomas and Demir, Ayhan S. and Siegert, Petra and Pohl, Martina and M{\"u}ller, Michael},
  title     = {Enantioselective Synthesis of (S)-2-Hydroxypropanone Derivatives by Benzoylformate Decarboxylase Catalyzed C-C Bond Formation},
  series = {European journal of organic chemistry},
  volume    = {Vol. 2000},
  journal   = {European journal of organic chemistry},
  number    = {Iss. 11},
  issn      = {0365-5490 (E-Journal); 1099-0690 (E-Journal); 0075-4617 (Print); 0170-2041 (Print); 0947-3440 (Print); 1434-193X (Print); 1434-243X (Print)},
  pages     = {2161 -- 2170},
  year      = {2000},
  language  = {en}
}
@article{NiehausGaborWielandetal.2011,
  author    = {Niehaus, F. and Gabor, E. and Wieland, S. and Siegert, Petra and Maurer, Karl-Heinz and Eck, J.},
  title     = {Enzymes for the laundry industries: tapping the vast metagenomic pool of alkaline proteases},
  series = {Microbial biotechnology},
  volume    = {Vol. 4},
  journal   = {Microbial biotechnology},
  number    = {Iss. 6},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1432-0614 (E-Journal); 0171-1741 (Print); 0175-7598 (Print); 0340-2118 (Print)},
  pages     = {767 -- 776},
  year      = {2011},
  language  = {en}
}
@article{SiegertMcLeishBaumannetal.2005,
  author    = {Siegert, Petra and McLeish, Michael J. and Baumann, Martin and Iding, Hans and Kneen, Malea M. and Kenyon, George L. and Pohl, Martina},
  title     = {Exchanging the substrate specificities of pyruvate decarboxylase from Zymomonas mobilis and benzoylformate decarboxylase from Pseudomonas putida},
  series = {Protein engineering, design, and selection : peds},
  volume    = {Vol. 18},
  journal   = {Protein engineering, design, and selection : peds},
  number    = {Iss. 7},
  issn      = {1460-213X (E-Journal); 1741-0134 (E-Journal); 0269-2139 (Print); 1741-0126 (Print)},
  pages     = {345 -- 357},
  year      = {2005},
  language  = {en}
}
@incollection{SiegertPohlKneenetal.2004,
  author    = {Siegert, Petra and Pohl, Martina and Kneen, Malea M. and Pogozheva, Irina D. and Kenyon, George L. and McLeish, Michael J.},
  title     = {Exploring the substrate specificity of benzoylformate decarboxylase, pyruvate decarboxylase, and benzaldehyde lyase},
  series = {Thiamine : catalytic mechanisms in normal and disease states / ed. by Frank Jordan ...},
  booktitle = {Thiamine : catalytic mechanisms in normal and disease states / ed. by Frank Jordan ...},
  publisher = {Dekker},
  address   = {New York, NY},
  isbn      = {0-8247-4062-9},
  pages     = {275 -- 290},
  year      = {2004},
  language  = {en}
}
@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}
}
@article{RibitschHeumannTrotschaetal.2011,
  author    = {Ribitsch, D. and Heumann, S. and Trotscha, E. and Herrero Acero, E. and Greimel, K. and Leber, R. and Birger-Gruenberger, R. and Deller, S. and Eiteljoerg, I. and Remler, P. and Weber, Th. and Siegert, Petra and Maurer, Karl-Heinz and Donelli, I. and Freddi, G. and Schwab, H. and Guebitz, G. M.},
  title     = {Hydrolysis of polyethyleneterephthalate by p-nitrobenzylesterase from Bacillus subtilis},
  series = {Biotechnology progress},
  volume    = {Vol. 27},
  journal   = {Biotechnology progress},
  number    = {Iss. 4},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1520-6033 (E-Journal); 8756-7938 (Print)},
  pages     = {951 -- 960},
  year      = {2011},
  language  = {en}
}