TY - JOUR A1 - Burger, René A1 - Rumpf, Jessica A1 - Do, Xuan Tung A1 - Monakhova, Yulia A1 - Diehl, Bernd W. K. A1 - Rehahn, Matthias A1 - Schulze, Margit T1 - Is NMR combined with multivariate regression applicable for the molecular weight determination of randomly cross-linked polymers such as lignin? JF - ACS Omega N2 - The molecular weight properties of lignins are one of the key elements that need to be analyzed for a successful industrial application of these promising biopolymers. In this study, the use of 1H NMR as well as diffusion-ordered spectroscopy (DOSY NMR), combined with multivariate regression methods, was investigated for the determination of the molecular weight (Mw and Mn) and the polydispersity of organosolv lignins (n = 53, Miscanthus x giganteus, Paulownia tomentosa, and Silphium perfoliatum). The suitability of the models was demonstrated by cross validation (CV) as well as by an independent validation set of samples from different biomass origins (beech wood and wheat straw). CV errors of ca. 7–9 and 14–16% were achieved for all parameters with the models from the 1H NMR spectra and the DOSY NMR data, respectively. The prediction errors for the validation samples were in a similar range for the partial least squares model from the 1H NMR data and for a multiple linear regression using the DOSY NMR data. The results indicate the usefulness of NMR measurements combined with multivariate regression methods as a potential alternative to more time-consuming methods such as gel permeation chromatography. Y1 - 2021 U6 - https://doi.org/10.1021/acsomega.1c03574 SN - 2470-1343 VL - 6 IS - 44 SP - 29516 EP - 29524 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Burmistrova, Natalia A. A1 - Soboleva, Polina M. A1 - Monakhova, Yulia T1 - Is infrared spectroscopy combined with multivariate analysis a promising tool for heparin authentication? JF - Journal of Pharmaceutical and Biomedical Analysis N2 - The investigation of the possibility to determine various characteristics of powder heparin (n = 115) was carried out with infrared spectroscopy. The evaluation of heparin samples included several parameters such as purity grade, distributing company, animal source as well as heparin species (i.e. Na-heparin, Ca-heparin, and heparinoids). Multivariate analysis using principal component analysis (PCA), soft independent modelling of class analogy (SIMCA), and partial least squares – discriminant analysis (PLS-DA) were applied for the modelling of spectral data. Different pre-processing methods were applied to IR spectral data; multiplicative scatter correction (MSC) was chosen as the most relevant. Obtained results were confirmed by nuclear magnetic resonance (NMR) spectroscopy. Good predictive ability of this approach demonstrates the potential of IR spectroscopy and chemometrics for screening of heparin quality. This approach, however, is designed as a screening tool and is not considered as a replacement for either of the methods required by USP and FDA. KW - IR spectroscopy KW - Heparin KW - Authenticity KW - Principal component analysis KW - Soft independent modeling of class analogy Y1 - 2021 SN - 0731-7085 U6 - https://doi.org/10.1016/j.jpba.2020.113811 VL - 194 IS - Article number: 113811 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Beging, Stefan A1 - Biselli, Manfred A1 - Poghossian, Arshak A1 - Wang, J. A1 - Zang, Werner A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Concept for a solid-state multi-parameter sensor system for cell-culture monitoring JF - Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI Y1 - 2009 SN - 0013-4686 SP - 6107 EP - 6112 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Delle, L. A1 - Poghossian, Arshak A1 - Biselli, Manfred A1 - Zang, Werner A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Electrochemical sensor array for bioprocess monitoring JF - Electrochimica Acta (2011) Y1 - 2011 VL - 56 IS - 26 SP - 9673 EP - 9678 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Rakowski, D. A1 - Poghossian, Arshak A1 - Biselli, Manfred A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis JF - Journal of Biotechnology N2 - A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses. Y1 - 2013 U6 - https://doi.org/10.1016/j.jbiotec.2012.03.014 SN - 0168-1656 VL - 163 IS - 4 SP - 371 EP - 376 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Raue, Markus A1 - Schusser, Sebastian A1 - Jeitner, C. A1 - Breuer, L. A1 - Wagner, P. A1 - Poghossian, Arshak A1 - Förster, Arnold A1 - Mang, Thomas A1 - Schöning, Michael Josef T1 - Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films JF - Physica Status Solidi (a) N2 - Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off. Y1 - 2012 U6 - https://doi.org/10.1002/pssa.201100763 SN - 1862-6319 VL - 209 IS - 5 SP - 839 EP - 845 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Canzoneri, M. A1 - Krüger, R. A1 - Zang, Werner A1 - Biselli, Manfred T1 - Atmungsaktivität von Säugerzellen: Kontinuierliche Onlineermittlung im Schüttelkolben JF - BIOforum. 3 (2006) Y1 - 2006 SN - 0940-0079 SP - 45 EP - 47 ER - TY - GEN A1 - Capitain, C. C. A1 - Lukeba, L. A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Biomimetische Klebstoffe aus Organosolv-Lignin T2 - Chemie Ingenieur Technik N2 - Aufgrund von EU-Regularien und Umweltinitiativen wächst der Markt für nachhaltige und abbaubare Klebstoffe stetig. Organosolv (OS)-Lignin ist ein kommerziell wenig ertragreicher Nebenstrom der Lignocellulose-Bioraffinerie. Durch das "Nachahmen" der Adhäsionseigenschaften mit strukturverwandten Muschel-Aminosäuren soll OS-Lignin in einen starkes, vollständig biobasiertes Adhäsiv umgewandelt werden. Funktionsweisend für die Adhäsion des Muschelklebstoffes ist die Catecholgruppe der Aminosäure L-DOPA. Die laccase-katalysierte Polymerisationsreaktion von Lignin und L-DOPA ist schwierig zu kontrollieren, da L-DOPA eine Ringschlussreaktion eingeht. Stattdessen wurde eine zweistufige Reaktion mit einem Diamin als Ankermolekül etabliert. Die Catecholgruppe, die im zweiten Schritt enzymatisch an das Lignin-Amin gebunden wird, kann durch Komplexbildung mit Fe(III)-Ionen sowohl zur Adhäsion als auch zur Kohäsion des Klebstoffes beitragen. Der Lignin-Catechol-Klebstoff ist frei von petrochemischen Chemikalien und biologisch abbaubar. In ersten Stirnzugversuchen konnte eine Haftkraft von 0,3 MPa erreicht werden. Y1 - 2018 U6 - https://doi.org/10.1002/cite.201855076 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung und 33. DECHEMA-Jahrestagung der Biotechnologen 2018, 10. - 13. September 2018, Eurogress Aachen VL - 90 IS - 9 SP - 1167 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Capitain, C. A1 - Hering, T. A1 - Tippkötter, Nils T1 - Enzymatische Polymerisation von Ligninmodellkomponenten und Organosolv-Lignin mit aromatischen Aminosäuren T2 - Chemie Ingenieur Technik N2 - Die stoffliche Nutzung von Lignin aus Bioraffinerien ist ein wichtiger Bestandteil für den Wertschöpfungsprozess von nachwachsenden, pflanzlichen Rohstoffen. Lignin zählt zu den wenigen erneuerbaren Quellen für phenolische Bestandteile, wird aber derzeit meist nur thermisch verwertet. Ziel dieses Forschungsvorhabens ist die Funktionalisierung von Lignin zur Verbesserung der Adhäsionseigenschaften. Als funktionelle Gruppe wird die aromatische Aminosäure L-DOPA verwendet, die charakteristisch für die Adhäsionskraft von Muscheln ist. Lignin ist ein geeignetes Stützgerüst, da es ein Polymer ist, das durch enzymkatalysierte Polymerisation gebildet wird. Essenziell für die Entwicklung ist ein besseres Verständnis über die Bildung von Lignin-Polymeren und deren verschiedene Eigenschaften. Um die Einflussfaktoren auf Kettenlänge und Polymerisationseffizienz zu untersuchen, werden zurzeit sowohl Ligninmodellkomponenten (LMK) als auch gelöstes Organosolv-Lignin verwendet. Laufende Untersuchungen werden zeigen, ob sich die enzymatische Polymerisationsreaktion auf ein gelöstes Ligninpolymer aus einem Organosolv-Aufschluss übertragen lässt. Y1 - 2016 U6 - https://doi.org/10.1002/cite.201650374 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung 2016 und 32. DECHEMA-Jahrestagung der Biotechnologen 2016, 12. - 15. September 2016, Eurogress Aachen VL - 88 IS - 9 SP - 1236 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Capitain, C. A1 - Hering, T. A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Enzymatic polymerization of lignin model compounds and solubilized lignin in an aqueous ethanol extract T2 - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany Y1 - 2016 SP - 151 EP - 152 PB - DECHEMA CY - Frankfurt am Main ER -