TY - JOUR A1 - Pasteur, Aline A1 - Tippkötter, Nils A1 - Kampeis, Percy A1 - Ulber, Roland T1 - Optimization of high gradient magnetic separation filter units for the purification of fermentation products JF - IEEE TRANSACTIONS ON MAGNETICS N2 - High gradient magnetic separation (HGMS) has been established since the early 1970s. A more recent application of these systems is the use in bioprocesses. To integrate the HGMS in a fermentation process, it is necessary to optimize the separation matrix with regard to the magnetic separation characteristics and permeability of the non-magnetizable components of the fermentation broth. As part of the work presented here, a combined fluidic and magnetic force finite element model simulation was created using the software COMSOL Multiphysics and compared with separation experiments. Finally, as optimal lattice orientation of the separation matrix, a transversal rhombohedral arrangement was defined. The high suitability of the new filter matrix has been verified by separation experiments. Y1 - 2014 U6 - https://doi.org/10.1109/TMAG.2014.2325535 SN - 0018-9464 N1 - Article Sequence Number: 5000607 INSPEC Accession Number: 14663042 VL - 50 IS - 10 SP - Artikel 5000607 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Tippkötter, Nils A1 - Wollny, Steffen A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - Recycling of spent oil bleaching earth as source of glycerol for the anaerobic production of acetone, butanol, and ethanol with Clostridium diolis and lipolytic Clostridium lundense JF - Engineering in Life Sciences N2 - A major part of edible oil is subjected to bleaching procedures, primarily with minerals applied as adsorbers. Their recycling is currently done either by regaining the oil via organic solvent extraction or by using the spent bleaching earth (SBE) as additive for animal feed, etc. As a new method, the reutilization of the by-product SBE for the microbiologic formation of acetone, butanol, and ethanol (ABE) is presented as proof-of-concept. The SBE was taken from a palm oil cleaning process. The recycling concept is based on the application of lipolytic clostridia strains. Due to considerably long fermentation times, co-fermentation with Candida rugosa and enzymatic hydrolyses of the bound oil with a subsequent clostridia fermentation are shown as alternative routes. Anaerobic fermentations under comparison of different clostridia strains were performed with glycerol media, enzymatically hydrolyzed palm oil and SBE. Solutes, side product compositions and productivities were quantified via HPLC. A successful production of ABE solutes from SBE has been done with a yield of 0.15 g butanol per gram of bound glycerol. Thus, the biotechnological recycling of the waste stream is possible in principle. Inhibition of the substrate suspension has been observed. A chromatographic ion-exchange of substrates increased the biomass concentration. Y1 - 2014 U6 - https://doi.org/10.1002/elsc.201300113 SN - 1618-2863 VL - 14 IS - 4 SP - 425 EP - 432 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Duwe, Anna A1 - Huster, Manuel A1 - Muffler, Kai A1 - Schlegel, Christin A1 - Sieker, Tim A1 - Stadtmüller, Ralf A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Biotechnologie und Bioverfahrenstechnik – Vom ersten Ullmanns Artikel bis hin zu aktuellen Forschungsthemen JF - Chemie Ingenieur Technik N2 - Biotechnologie und die mit ihr verbundenen technischen Prozesse prägen seit Jahrtausenden die Entwicklung der Menschheit. Ausgehend von empirischen Verfahren, insbesondere zur Herstellung von Lebensmitteln und täglichen Gebrauchsgütern, haben sich diese Disziplinen zu einem der innovativsten Zukunftsfelder entwickelt. Durch das immer detailliertere Verständnis zellulärer Vorgänge können mittlerweile Produktionsstämme gezielt optimiert werden. Im Zusammenspiel mit moderner Prozesstechnik können so eine Vielzahl von Bulk- und Feinchemikalien sowie Pharmazeutika effizient hergestellt werden. In diesem Artikel werden exemplarisch einige der aktuellen Trends vorgestellt. Y1 - 2014 U6 - https://doi.org/10.1002/cite.201400083 SN - 0009-286X VL - 86 IS - 12 SP - 2215 EP - 2225 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Wiesen, Sebastian A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Nils A1 - Ulber, Roland T1 - Adsorptive Vorbehandlung von Rohglycerin für die 1,3-Propandiol Fermentation mit Clostridium diolis JF - Chemie Ingenieur Technik N2 - Bei der Gewinnung von Fettsäuren aus Pflanzenölen, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, fällt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fettsäuren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fettsäuren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erhöhen. Y1 - 2014 U6 - https://doi.org/10.1002/cite.201300080 N1 - Englischer Titel: Adsorptive Pretreatment of Crude Glycerol Prior to Fermentation to 1,3-Propanediole by Clostridium Diolis VL - 86 IS - 1-2 SP - 129 EP - 135 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Thiel, Alexander A1 - Tippkötter, Nils A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - New zeolite adsorbents for downstream processing of polyphenols from renewable resources JF - Engineering in Life Sciences N2 - Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources. Y1 - 2013 U6 - https://doi.org/10.1002/elsc.201200188 VL - 13 IS - 3 SP - 239 EP - 246 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Al-Kaidy, Huschyar A1 - Wollny, Steffen A1 - Ulber, Roland T1 - Functionalized magnetizable particles for downstream processing in single-use systems JF - Chemie Ingenieur Technik N2 - Biotechnological downstream processing is usually an elaborate procedure, requiring a multitude of unit operations to isolate the target component. Besides the disadvantageous space-time yield, the risks of cross-contaminations and product loss grow fast with the complexity of the isolation procedure. A significant reduction of unit operations can be achieved by application of magnetic particles, especially if these are functionalized with affinity ligands. As magnetic susceptible materials are highly uncommon in biotechnological processes, target binding and selective separation of such particles from fermentation or reactions broths can be done in a single step. Since the magnetizable particles can be produced from iron salts and low priced polymers, a single-use implementation of these systems is highly conceivable. In this article, the principles of magnetizable particles, their synthesis and functionalization are explained. Furthermore, applications in the area of reaction engineering, microfluidics and downstream processing are discussed focusing on established single-use technologies and development potential. Y1 - 2013 U6 - https://doi.org/10.1002/cite.201200130 VL - 85 IS - 1-2: Special Issue: Single-Use Technology SP - 76 EP - 86 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development JF - Engineering in Life Sciences N2 - Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step. Y1 - 2011 U6 - https://doi.org/10.1002/elsc.201000160 N1 - Special Issue "Bioprocess‐oriented plant design" VL - 11 IS - 4 SP - 436 EP - 442 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Poth, Sebastian A1 - Monzon, Magaly A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Lignocellulosic biorefinery: Process integration of hydrolysis and fermentation (SSF process) JF - Holzforschung N2 - The aim of the present work is the process integration and the optimization of the enzymatic hydrolysis of wood and the following fermentation of the products to ethanol. The substrate is a fiber fraction obtained by organosolv pre-treatment of beech wood. For the ethanol production, a co-fermentation by two different yeasts (Saccharomyces cerevisiae and Pachysolen tannophilus) was carried out to convert glucose as well as xylose. Two approaches has been followed: 1. A two step process, in which the hydrolysis of the fiber fraction and the fermentation to product are separated from each other. 2. A process, in which the hydrolysis and the fermentation are carried out in one single process step as simultaneous saccharification and fermentation (SSF). Following the first approach, a yield of about 0.15 g ethanol per gram substrate can be reached. Based on the SSF, one process step can be saved, and additionally, the gained yield can be raised up to 0.3 g ethanol per gram substrate. Y1 - 2011 N1 - 11th EWLP, Hamburg, Germany, August 16–19, 2010 VL - 65 IS - 5 SP - 633 EP - 637 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roikaew, Wipa A1 - Ulber, Roland A1 - Hoffmann, Alexander A1 - Denzler, Hans-Jörg A1 - Buchholz, Heinrich T1 - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food JF - Biotechnology Progress N2 - Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. Y1 - 2010 U6 - https://doi.org/10.1002/btpr.384 SN - 8756-7938 VL - 26 IS - 3 SP - 756 EP - 762 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Grassilage als Rohstoff für die chemische Industrie JF - Chemie Ingenieur Technik N2 - Grassilage stellt einen nachwachsenden Rohstoff mit großem Potenzial dar. Neben Cellulose und Hemicellulose enthält sie auch organische Säuren, insbesondere Milchsäure. In einem Bioraffinerie-Projekt wird die Milchsäure aus der Silage isoliert und mit gentechnisch optimierten Stämmen 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 sämtliche Inhaltsstoffe der Silage verwertet. Y1 - 2010 U6 - https://doi.org/10.1002/cite.201000088 SN - 1522-2640 VL - 82 IS - 8, Special Issue: Industrielle Nutzung nachwachsender Rohstoffe SP - 1153 EP - 1159 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Ulber, Roland A1 - Poth, Sebastian A1 - Monzon, Magaly A1 - Tippkötter, Nils T1 - Prozessintegration von Hydrolyse und Fermentation von Cellulose- Faserstoff JF - Chemie Ingenieur Technik N2 - Ein viel versprechender erneuerbarer Rohstoff für die Produktion von Chemikalien und Treibstoffen ist Lignocellulose aus pflanzlicher Biomasse. Die darin enthaltenen Zucker können mittels enzymatischer Hydrolyse freigesetzt und fermentativ zu Ethanol umgesetzt werden. Ein interessanter Ansatz ist dabei die simultane Verzuckerung und Fermentation. Hefen und Enzyme haben mit 30 °C bzw. 50 °C zwar unterschiedliche Temperaturoptima, es konnte aber gezeigt werden, dass auch bei den niedrigeren Temperaturen eine Umsetzung der Cellulose zu Glucose erfolgt, wenn auch langsamer als bei optimalen Bedingungen. Außerdem konnte in Vorversuchen gezeigt werden, dass Ethanol in den zu erwartenden Konzentrationen keinen Einfluss auf die enzymatische Umsetzung hat. Y1 - 2010 U6 - https://doi.org/10.1002/cite.200900103 SN - 1522-2640 N1 - Special Issue "Biokatalyse" VL - 82 IS - 1-2 SP - 135 EP - 139 ER - TY - JOUR A1 - Tippkötter, Nils A1 - Deterding, A. A1 - Ulber, Roland T1 - Determination of acetic acid in fermentation broth by gas-diffusion technique JF - Engineering in Life Sciences N2 - Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents. Y1 - 2008 U6 - https://doi.org/10.1002/elsc.200820227 VL - 8 IS - 1, Special Issue: Technical Systems for the Use in Life Sciences SP - 62 EP - 67 ER - TY - JOUR A1 - Kappler-Tanudyaya, Nathalie A1 - Schmitt, Heike A1 - Tippkötter, Nils A1 - Meyer, Lina A1 - Lenzen, Sigurd A1 - Ulber, Roland T1 - Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose JF - Biotechnology Journal N2 - Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently. Y1 - 2007 U6 - https://doi.org/10.1002/biot.200700004 SN - 1860-7314 VL - 2 IS - 6 SP - 692 EP - 699 ER - TY - JOUR A1 - Rösch, C. A1 - Kratz, F. A1 - Hering, T. A1 - Trautmann, S. A1 - Umanskaya, N. A1 - Tippkötter, Nils A1 - Müller-Renno, C.M. A1 - Ulber, Roland A1 - Hannig, M. A1 - Ziegler, C. T1 - Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity JF - Colloids and Surfaces B: Biointerfaces N2 - The interplay of albumin (BSA) and lysozyme (LYZ) adsorbed simultaneously on titanium was analyzed by gel electrophoresis and BCA assay. It was found that BSA and lysozyme adsorb cooperatively. Additionally, the isoelectric point of the respective protein influences the adsorption. Also, the enzymatic activity of lysozyme and amylase (AMY) in mixtures with BSA was considered with respect to a possible influence of protein-protein interaction on enzyme activity. Indeed, an increase of lysozyme activity in the presence of BSA could be observed. In contrast, BSA does not influence the activity of amylase. Y1 - 2016 U6 - https://doi.org/10.1016/j.colsurfb.2016.09.048 VL - 149 IS - 1 SP - 115 EP - 121 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Roth, Jasmine A1 - Tippkötter, Nils T1 - Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium JF - Cellulose Chemistry and Technology N2 - Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹. Y1 - 2016 VL - 50 IS - 3-4 SP - 405 EP - 410 PB - Editura Academiei Romane CY - Bukarest ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Tippkötter, Nils T1 - Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase JF - Engineering in Life Sciences N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1002/elsc.201400124 VL - 16 IS - 3 SP - 222 EP - 230 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Duwe, Anna A1 - Huster, Manuel A1 - Muffler, Kai A1 - Schlegel, Christin A1 - Tim, Sieker A1 - Stadtmüller, Ralf A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Biotechnology and bioprocess engineering – from the first ullmann's article to recent trends JF - ChemBioEng Reviews N2 - For several thousand years, biotechnology and its associated technical processes have had a great impact on the development of mankind. Based on empirical methods, in particular for the production of foodstuffs and daily commodities, these disciplines have become one of the most innovative future issues. Due to the increasing detailed understanding of cellular processes, production strains can now be optimized. In combination with modern bioprocesses, a variety of bulk and fine chemicals as well as pharmaceuticals can be produced efficiently. In this article, some of the current trends in biotechnology are discussed. Y1 - 2015 U6 - https://doi.org/10.1002/cben.201500008 VL - 2 IS - 3 SP - 175 EP - 184 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Wollny, S. A1 - Kampeis, P. A1 - Oster, J. A1 - Schneider, H. A1 - Ulber, Roland T1 - Magnetseparation von Proteinen : Separation von Zielmolekülen durch hochselektive Aptamere JF - GIT Labor-Fachzeitschrift N2 - Durch die Kombination von Oligonukleotid-Liganden (Aptameren) hoher Bindungsaffinitäten mit hochselektiv abtrennbaren magnetisierbaren Mikropartikeln wird eine einstufige Separation von Zielmolekülen aus mikrobiologischen Produktionsansätzen möglich. Die Aptamere werden hierfür reversibel auf den Partikeloberflächen gebunden und für die spezifische Isolierung von Bioprodukten eingesetzt. Die Abtrennung der beladenen Partikel erfolgt durch einen neuen Rotor-Stator-Separator mit Hochgradient-Magnetfeld. Y1 - 2011 VL - 55 IS - 10 SP - 666 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Sieker, Tim A1 - Ulber, Roland A1 - Dimitrova, Darina A1 - Bart, Hans-Jörg A1 - Neuner, Andreas A1 - Heinzle, Elmar A1 - Tippkötter, Nils T1 - Silage : Fermentationsrohstoff für die chemische Industrie? JF - labor&more N2 - In Anbetracht des zu erwartenden Rückgangs der Verfügbarkeit fossiler Rohstoffe müssen nicht nur für den Energiesektor, sondern auch für die Herstellung industrieller Produkte alternative Rohstoffe gefunden werden. Ein Beispiel für einen nicht in Nahrungsmittelkonkurrenz stehenden nachwachsenden Rohstoff ist grüne Biomasse wie Gras und Klee. Diese lassen sich in Deutschland auf großen Flächen anbauen und enthalten eine Vielzahl potenzieller Substrate für Fermentationen. Y1 - 2009 IS - 2 SP - 44 EP - 45 ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Kuthan, Kai A1 - Hering, Thomas A1 - Tippkötter, Nils T1 - Aqueous droplets used as enzymatic microreactors and their electromagnetic actuation JF - Journal of Visualized Experiments N2 - For the successful implementation of microfluidic reaction systems, such as PCR and electrophoresis, the movement of small liquid volumes is essential. In conventional lab-on-a-chip-platforms, solvents and samples are passed through defined microfluidic channels with complex flow control installations. The droplet actuation platform presented here is a promising alternative. With it, it is possible to move a liquid drop (microreactor) on a planar surface of a reaction platform (lab-in-a-drop). The actuation of microreactors on the hydrophobic surface of the platform is based on the use of magnetic forces acting on the outer shell of the liquid drops which is made of a thin layer of superhydrophobic magnetite particles. The hydrophobic surface of the platform is needed to avoid any contact between the liquid core and the surface to allow a smooth movement of the microreactor. On the platform, one or more microreactors with volumes of 10 µL can be positioned and moved simultaneously. The platform itself consists of a 3 x 3 matrix of electrical double coils which accommodate either neodymium or iron cores. The magnetic field gradients are automatically controlled. By variation of the magnetic field gradients, the microreactors' magnetic hydrophobic shell can be manipulated automatically to move the microreactor or open the shell reversibly. Reactions of substrates and corresponding enzymes can be initiated by merging the microreactors or bringing them into contact with surface immobilized catalysts. Y1 - 2016 U6 - https://doi.org/10.3791/54643 SN - 1940-087X IS - Issue 126 ER - TY - JOUR A1 - Braband, Henrik A1 - Paulßen, Elisabeth A1 - Abram, Ulrich T1 - Nitridorhenium(V) Complexes with 1,3-Dialkyl-4,5-dimethylimidazole-2-ylidenes JF - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry Y1 - 2006 U6 - https://doi.org/10.1002/zaac.200600002 SN - 1521-3749 VL - 632 IS - 6 SP - 1051 EP - 1056 ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Schweighöfer, Philip V. A1 - Abram, Ulrich T1 - Reactions of [ReOX3(PPh3)2] Complexes (X = Cl, Br) with Phenylacetylene and the Structures of the Products JF - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry N2 - Oxorhenium(V) complexes [ReOX3(PPh3)2] (X = Cl, Br) react with phenylacetylene under formation of complexes with ylide-type ligands. Compounds of the compositions [ReOCl3(PPh3){C(Ph)C(H)(PPh3)}] (1), [ReOBr3(OPPh3){C(Ph)C(H)(PPh3)}] (2), and [ReOBr3(OPPh3){C(H)C(Ph)(PPh3)}] (3) were isolated and characterized by X-ray diffraction. They contain a ligand, which was formed by a nucleophilic attack of released PPh3 at coordinated phenylacetylene. The structures of the products show that there is no preferable position for this attack. Cleavage of the Re–C bond in 3 and dimerization of the organic ligand resulted in the formation of the [{(PPh3)(H)CC(Ph)}2]2+ cation, which crystallized as its [(ReOBr4)(OReO3)]2– salt. Y1 - 2010 U6 - https://doi.org/10.1002/zaac.200900478 SN - 1521-3749 VL - 636 IS - 5 SP - 779 EP - 783 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Kückmann, Theresa A1 - Abram, Ulrich T1 - Silver(I) Complexes of 1,3-Dialkyl-4,5-dimethylimidazol-2-ylidenes and their Use as Precursors for the Synthesis of Rhenium(V) NHC Complexes JF - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry Y1 - 2007 U6 - https://doi.org/10.1002/zaac.200700021 SN - 1521-3749 VL - 633 IS - 5-6 SP - 830 EP - 834 ER - TY - JOUR A1 - Braband, Henrik A1 - Yegen, Eda A1 - Paulßen, Elisabeth A1 - Abram, Ulrich T1 - [{ReN(PMe2Ph)3}{ReO3N}]2 – Structural Evidence for the Nitridotrioxorhenate(VII) Anion, [ReO3N]2− JF - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry Y1 - 2005 U6 - https://doi.org/10.1002/zaac.200500240 SN - 1521-3749 VL - 631 IS - 12 SP - 2408 EP - 2410 ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Alberto, Roger A1 - Abram, Ulrich T1 - Synthesis, Characterization, and Structures of R3EOTcO3 Complexes (E = C, Si, Ge, Sn, Pb) and Related Compounds JF - Inorganic Chemistry N2 - AgTcO4 reacts with R3ECl compounds (E = C, Si, Ge, Sn, Pb; R = Me, iPr, tBu, Ph), tBu2SnCl2, or PhMgCl under formation of novel trioxotechnetium(VII) derivatives. The carbon and silicon derivatives readily undergo decomposition, which was proven by 99Tc NMR spectroscopy and the isolation of decomposition products such as [TcOCl3(THF)(OH2)]. Compounds [Ph3GeOTcO3], [(THF)Ph3SnOTcO3], [(O3TcO)SntBu2(OH)]2, and [(THF)4Mg(OTcO3)2] are more stable and were isolated in crystalline form and characterized by X-ray diffraction. Y1 - 2010 U6 - https://doi.org/10.1021/ic1001094 SN - 1520-510X VL - 49 IS - 7 SP - 3525 EP - 3530 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Kong, Shushu A1 - Arciszewski, Pawel A1 - Wielbalck, Swantje A1 - Abram, Ulrich T1 - Aryl and NHC Compounds of Technetium and Rhenium JF - Journal of the American Chemical Society N2 - Air- and water-stable phenyl complexes with nitridotechnetium(V) cores can be prepared by straightforward procedures. [TcNPh2(PPh3)2] is formed by the reaction of [TcNCl2(PPh3)2] with PhLi. The analogous N-heterocyclic carbene (NHC) compound [TcNPh2(HLPh)2], where HLPh is 1,3,4-triphenyl-1,2,4-triazol-5-ylidene, is available from (NBu4)[TcNCl4] and HLPh or its methoxo-protected form. The latter compound allows the comparison of different Tc–C bonds within one compound. Surprisingly, the Tc chemistry with such NHCs does not resemble that of corresponding Re complexes, where CH activation and orthometalation dominate. Y1 - 2012 U6 - https://doi.org/10.1021/ja3033718 SN - 1520-5126 VL - 134 IS - 22 SP - 9118 EP - 9121 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Barbazán, Paula A1 - Hagenbach, Adelheid A1 - Paulßen, Elisabeth A1 - Abram, Ulrich A1 - Carballo, Rosa A1 - Rodriguez-Hermida, Sabina A1 - Vázquez-López, Ezequiel M. T1 - Tricarbonyl Rhenium(I) and Technetium(I) Complexes with Hydrazones Derived from 4,5-Diazafluoren-9-one and 1,10-Phenanthroline-5,6-dione JF - European Journal of Inorganic Chemistry N2 - Tricarbonylrhenium(I) and -technetium(I) halide (halide = Cl and Br) complexes of ligands derived from 4,5-diazafluoren-9-one (df) and 1,10-phenanthroline-5,6-dione (phen) derivatives of benzoic and 2-hydroxybenzoic acid hydrazides have been prepared. The complexes have been characterized by elemental analysis, MS, IR, 1H NMR and absorption and emission UV/Vis spectroscopic methods. The metal centres (ReI and TcI) are coordinated through the nitrogen imine atoms and establish five-membered chelate rings, whereas the hydrazone groups stand uncoordinated. The 1H NMR spectra suggest the same behaviour in solution on the basis of only marginal variations in the chemical shifts of the hydrazine protons. Y1 - 2010 U6 - https://doi.org/10.1002/ejic.201000522 SN - 1099-0682 IS - 29 SP - 4622 EP - 4630 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Ngyugen, Hung Huy A1 - Kahlcke, Nils A1 - Deflon, Victor M. A1 - Abram, Ulrich T1 - Tricarbonyltechnetium(I) and -rhenium(I) complexes with N′-thiocarbamoylpicolylbenzamidines JF - Polyhedron N2 - N,N-Dialkylamino(thiocarbonyl)-N′-picolylbenzamidines react with (NEt4)2[M(CO)3X3] (M = Re, X = Br; M = Tc, X = Cl) under formation of neutral [M(CO)3L] complexes in high yields. The monoanionic NNS ligands bind in a facial coordination mode and can readily be modified at the (CS)NR1R2 moiety. The complexes [99Tc(CO)3(LPyMor)] and [Re(CO)3(L)] (L = LPyMor, LPyEt) were characterized by X-ray diffraction. Reactions of [99mTc(CO)3(H2O)3]+ with the N′-thiocarbamoylpicolylbenzamidines give the corresponding 99mTc complexes. The ester group in HLPyCOOEt allows linkage between biomolecules and the metal core. Y1 - 2012 U6 - https://doi.org/10.1016/j.poly.2012.04.008 SN - 0277-5387 VL - 40 IS - 1 SP - 153 EP - 158 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pellegrini, Paul A. A1 - Howell, Nicholas R. A1 - Shepherd, Rachael K. A1 - Lengkeek, Nigel A. A1 - Paulßen, Elisabeth A1 - Katsifis, Andrew G. A1 - Greguric, Ivan T1 - Synthesis and Radiolabelling of DOTA-Linked Glutamine Analogues with 67,68Ga as Markers for Increased Glutamine Metabolism in Tumour Cells JF - Molecules Y1 - 2013 U6 - https://doi.org/10.3390/molecules18067160 SN - 1420-3049 VL - 18 IS - 6 SP - 7160 EP - 7178 PB - MDPI CY - Basel ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Le, Van So A1 - Lengkeek, Nigel A1 - Pellegrini, Paul A1 - Jackson, Tim A1 - Greguric, Ivan A1 - Weiner, Ron T1 - Influence of Metal Ions on the 68Ga-labeling of DOTATATE JF - Applied Radiation and Isotopes Y1 - 2013 U6 - https://doi.org/10.1016/j.apradiso.2013.08.010 SN - 1872-9800 VL - 82 SP - 232 EP - 238 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Lengkeek, Nigel A. A1 - Le, Van So A1 - Pellegrini, Paul A. A1 - Greguric, Ivan A1 - Weiner, Ron T1 - The role of additives in moderating the influence of Fe(III) and Cu(II) on the radiochemical yield of [⁶⁸Ga(DOTATATE)] JF - Applied Radiation and Isotopes N2 - [⁶⁸Ga(DOTATATE)] has demonstrated its clinical usefulness. Both Fe³⁺ and Cu²⁺, potential contaminants in Gallium-68 generator eluent, substantially reduce the radiochemical (RC) yield of [⁶⁸Ga(DOTATATE)] if the metal/ligand ratio of 1:1 is exceeded. A variety of compounds were examined for their potential ability to reduce this effect. Most had no effect on RC yield. However, addition of phosphate diminished the influence of Fe³⁺ by likely forming an insoluble iron salt. Addition of ascorbic acid reduced Cu²⁺ and Fe³⁺ to Cu⁺ and Fe²⁺ respectively, both of which have limited impact on RC yields. At low ligand amounts (5 nmol DOTATATE), the addition of 30 nmol phosphate (0.19 mM) increased the tolerance of Fe3⁺ from 4 nmol to 10 nmol (0.06 mM), while the addition of ascorbic acid allowed high RC yields (>95%) in the presence of 40 nmol Fe³⁺ (0.25 mM) and 100 nmol Cu²⁺ (0.63 mM). The effect of ascorbic acid was highly pH-dependant, and gave optimal results at pH 3. Y1 - 2016 U6 - https://doi.org/10.1016/j.apradiso.2015.09.008 SN - 1872-9800 VL - 107 SP - 13 EP - 16 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Paulßen, Elisabeth A1 - Hoehr, Cornelia A1 - Hou, Xinchi A1 - Hanemaayer, Victoire A1 - Zeisler, Stefan A1 - Adam, Michael J. A1 - Ruth, Thomas J. A1 - Celler, Anna A1 - Buckley, Ken A1 - Benard, Francois A1 - Schaffer, Paul T1 - Production of Y-86 and other radiometals for research purposes using a solution target system JF - Nuclear medicine and biology Y1 - 2015 U6 - https://doi.org/10.1016/j.nucmedbio.2015.06.005 SN - 1872-9614 VL - 42 IS - 11 SP - 842 EP - 849 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hoehr, Cornelia A1 - Paulßen, Elisabeth A1 - Benard, Francois A1 - Lee, Chris Jaeil A1 - Hou, Xinchi A1 - Badesso, Brian A1 - Ferguson, Simon A1 - Miao, Qing A1 - Yang, Hua A1 - Buckley, Ken A1 - Hanemaayer, Victoire A1 - Zeisler, Stefan A1 - Ruth, Thomas A1 - Celler, Anna A1 - Schaffer, Paul T1 - ⁴⁴ᶢSc production using a water target on a 13 MeV cyclotron JF - Nuclear medicine and biology N2 - Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t₁⸝₂ = 3.97 h, Eavg,β⁺ = 1.47 MeV, branching ratio = 94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations. Y1 - 2014 U6 - https://doi.org/10.1016/j.nucmedbio.2013.12.016 SN - 1872-9614 VL - 41 IS - 5 SP - 401 EP - 406 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Infantino, Angelo A1 - Paulßen, Elisabeth A1 - Mostacci, Domiziano A1 - Schaffer, Paul A1 - Trinczek, Michael A1 - Hoehr, Cornelia T1 - Assessment of the production of medical isotopes using the Monte Carlo code FLUKA: Simulations against experimental measurements JF - Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms N2 - The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, ¹⁸F, ¹³N, ⁹⁴Tc, ⁴⁴Sc, ⁶⁸Ga, ⁸⁶Y, ⁸⁹Zr, ⁵²Mn, ⁶¹Cu and ⁵⁵Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of ⁵⁵Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy. Y1 - 2016 U6 - https://doi.org/10.1016/j.nimb.2015.10.067 SN - 1872-9584 VL - 366 SP - 117 EP - 123 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Liu, Z. A1 - Schaap, K. S. A1 - Ballemans, L. A1 - de Blois, E. A1 - Rohde, M. A1 - Paulßen, Elisabeth T1 - Measurement of reaction kinetics of [177Lu]Lu-DOTA-TATE using a microfluidic system JF - Dalton Transactions Y1 - 2017 U6 - https://doi.org/10.1039/C7DT01830D SN - 1477-9234 VL - 46 IS - 42 SP - 14669 EP - 14676 ER - TY - JOUR A1 - Raupp, Sebastian M. A1 - Schmitt, Marcel A1 - Walz, Anna-Lena A1 - Diehm, Ralf A1 - Hummel, Helga A1 - Scharfer, Philip A1 - Schabel, Wilhelm T1 - Slot die stripe coating of low viscous fluids JF - Journal of Coatings Technology and Research N2 - Slot die coating is applied to deposit thin and homogenous films in roll-to-roll and sheet-to-sheet applications. The critical step in operation is to choose suitable process parameters within the process window. In this work, we investigate an upper limit for stripe coatings. This maximum film thickness is characterized by stripe merging which needs to be avoided in a stable process. It is shown that the upper limit reduces the process window for stripe coatings to a major extent. As a result, stripe coatings at large coating gaps and low viscosities are only possible for relatively thick films. Explaining the upper limit, a theory of balancing the side pressure in the gap region in the cross-web direction has been developed. Y1 - 2018 U6 - https://doi.org/10.1007/s11998-017-0039-y SN - 1935-3804 VL - 15 IS - 5 SP - 899 EP - 911 PB - Springer ER - TY - JOUR A1 - Delaittre, Guillaume T1 - Telechelic Poly(2-Oxazoline)s JF - European Polymer Journal Y1 - 2019 U6 - https://doi.org/10.1016/j.eurpolymj.2019.109281 SN - 0014-3057 IS - In Press, Journal Pre-proof, 109281 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Capitain, Charlotte A1 - Wagner, Sebastian A1 - Hummel, Joana A1 - Tippkötter, Nils T1 - Investigation of C–N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion JF - Waste and Biomass Valorization Y1 - 2021 U6 - https://doi.org/10.1007/s12649-020-01110-5 SN - 1877-265X N1 - Corresponding author: Nils Tippkötter VL - 12 SP - 1761 EP - 1779 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Schmidt, Aaron C. A1 - Turgut, Hatice A1 - Le, Dao A1 - Beloqui, Ana A1 - Delaittre, Guillaume T1 - Making the best of it: nitroxide-mediated polymerization of methacrylates via the copolymerization approach with functional styrenics JF - Polymer Chemistry N2 - The SG1-mediated solution polymerization of methyl methacrylate (MMA) and oligo(ethylene glycol) methacrylate (OEGMA, Mₙ = 300 g mol⁻¹) in the presence of a small amount of functional/reactive styrenic comonomer is investigated. Moieties such as pentafluorophenyl ester, triphenylphosphine, azide, pentafluorophenyl, halide, and pyridine are considered. A comonomer fraction as low as 5 mol% typically results in a controlled/living behavior, at least up to 50% conversion. Chain extensions with styrene for both systems were successfully performed. Variation of physical properties such as refractive index (for MMA) and phase transition temperature (for OEGMA) were evaluated by comparing to 100% pure homopolymers. The introduction of an activated ester styrene derivative in the polymerization of OEGMA allows for the synthesis of reactive and hydrophilic polymer brushes with defined thickness. Finally, using the example of pentafluorostyrene as controlling comonomer, it is demonstrated that functional PMMA-b-PS are able to maintain a phase separation ability, as evidenced by the formation of nanostructured thin films. Y1 - 2020 U6 - https://doi.org/10.1039/C9PY01458F VL - 11 IS - 2 SP - 593 EP - 604 PB - Royal Society of Chemistry (RSC) CY - Cambridge ER - TY - JOUR A1 - Muschallik, Lukas A1 - Molinnus, Denise A1 - Jablonski, Melanie A1 - Kipp, Carina Ronja A1 - Bongaerts, Johannes A1 - Pohl, Martina A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Selmer, Thorsten A1 - Siegert, Petra T1 - Synthesis of α-hydroxy ketones and vicinal (R, R)-diols by Bacillus clausii DSM 8716ᵀ butanediol dehydrogenase JF - RSC Advances N2 - α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the R-selective 2,3-butanediol dehydrogenase from B. clausii DSM 8716ᵀ (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed. In addition, surprisingly alkyl phenyl dicarbonyls, like 2-hydroxy-1-phenylpropan-1-one and phenylglyoxal are accepted, whereas their derivatives with two phenyl groups are not substrates. Supplementation of Mn²⁺ (1 mM) increases BcBDH's activity in biotransformations. Furthermore, the biocatalytic reduction of 5-methyl-2,3-hexanedione to mainly 5-methyl-3-hydroxy-2-hexanone with only small amounts of 5-methyl-2-hydroxy-3-hexanone within an enzyme membrane reactor is demonstrated. Y1 - 2020 U6 - https://doi.org/10.1039/D0RA02066D SN - 2046-2069 VL - 10 SP - 12206 EP - 12216 PB - Royal Society of Chemistry (RSC) CY - Cambridge ER - TY - JOUR A1 - Capitain, Charlotte A1 - Ross-Jones, Jesse A1 - Möhring, Sophie A1 - Tippkötter, Nils T1 - Differential scanning calorimetry for quantification of polymer biodegradability in compost JF - International Biodeterioration & Biodegradation N2 - The objective of this study is the establishment of a differential scanning calorimetry (DSC) based method for online analysis of the biodegradation of polymers in complex environments. Structural changes during biodegradation, such as an increase in brittleness or crystallinity, can be detected by carefully observing characteristic changes in DSC profiles. Until now, DSC profiles have not been used to draw quantitative conclusions about biodegradation. A new method is presented for quantifying the biodegradation using DSC data, whereby the results were validated using two reference methods. The proposed method is applied to evaluate the biodegradation of three polymeric biomaterials: polyhydroxybutyrate (PHB), cellulose acetate (CA) and Organosolv lignin. The method is suitable for the precise quantification of the biodegradability of PHB. For CA and lignin, conclusions regarding their biodegradation can be drawn with lower resolutions. The proposed method is also able to quantify the biodegradation of blends or composite materials, which differentiates it from commonly used degradation detection methods. Y1 - 2020 U6 - https://doi.org/10.1016/j.ibiod.2020.104914 SN - 0964-8305 VL - 149 SP - In Press, Article number 104914 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wardoyo, Arinto Y.P. A1 - Noor, Johan A.E. A1 - Elbers, Gereon A1 - Schmitz, Sandra A1 - Flaig, Sascha T. A1 - Budianto, Arif T1 - Characterizing volcanic ash elements from the 2015 eruptions of bromo and raung volcanoes, Indonesia JF - Polish Journal of Environmental Studies N2 - The volcanic eruptions of Mt. Bromo and Mt. Raung in East Java, Indonesia, in 2015 perturbed volcanic materials and affected surface-layer air quality at surrounding locations. During the episodes, the volcanic ash from the eruptions influenced visibility, traffic accidents, flight schedules, and human health. In this research, the volcanic ash particles were collected and characterized by relying on the detail of physical observation. We performed an assessment of the volcanic ash elements to characterize the volcanic ash using two different methods which are aqua regia extracts followed by MP-AES and XRF laboratory test of bulk samples. The analysis results showed that the volcanic ash was mixed of many materials, such as Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Ni, and others. Fe, Si, Ca, and Al were found as the major elements, while the others were the trace elements Ba, Cr, Cu, Mn, P, Mn, Ni, Zn, Sb, Sr, and V with the minor concentrations. XRF analyses showed that Fe dominated the elements of the volcanic ash. The XRF analysis showed that Fe was at 35.40% in Bromo and 43.00% in Raung of the detected elements in bulk material. The results of aqua regia extracts analyzed by MP-AES were 1.80% and 1.70% of Fe element for Bromo and Raung volcanoes, respectively. Y1 - 2020 U6 - https://doi.org/10.15244/pjoes/99101 SN - 2083-5906 VL - 29 IS - 2 SP - 1899 EP - 1907 PB - HARD CY - Olsztyn ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Reinecke, Diana A1 - Klose, Holger A1 - Kuperjans, Isabel A1 - Grömping, Markus T1 - Anaerobic digestion of algal–bacterial biomass of an Algal Turf Scrubber system JF - Biomass Conversion and Biorefinery N2 - This study investigated the anaerobic digestion of an algal–bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal–bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4%) and a mixture of manure and maize silage (107.4%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6%) and percolated green waste (43.5%) inocula. To further evaluate the potential of algal–bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7–12.5 MWh a−1) can be gained through the addition of algal–bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies. KW - Biogas KW - Methane KW - Algal Turf Scrubber KW - Algal–bacterial bioflm KW - Circular bioeconomy Y1 - 2022 U6 - https://doi.org/10.1007/s13399-022-03236-z SN - 2190-6823 N1 - Corresponding author: Dheeraja Cheenakula VL - 13 SP - 15 Seiten PB - Springer CY - Berlin ER - TY - JOUR A1 - Monakhova, Yulia A1 - Diehl, Bernd W.K. T1 - Nuclear magnetic resonance spectroscopy as an elegant tool for a complete quality control of crude heparin material JF - Journal of Pharmaceutical and Biomedical Analysis N2 - Nuclear magnetic resonance (NMR) spectrometric methods for the quantitative analysis of pure heparin in crude heparin is proposed. For quantification, a two-step routine was developed using a USP heparin reference sample for calibration and benzoic acid as an internal standard. The method was successfully validated for its accuracy, reproducibility, and precision. The methodology was used to analyze 20 authentic porcine heparinoid samples having heparin content between 4.25 w/w % and 64.4 w/w %. The characterization of crude heparin products was further extended to a simultaneous analysis of these common ions: sodium, calcium, acetate and chloride. A significant, linear dependence was found between anticoagulant activity and assayed heparin content for thirteen heparinoids samples, for which reference data were available. A Diffused-ordered NMR experiment (DOSY) can be used for qualitative analysis of specific glycosaminoglycans (GAGs) in heparinoid matrices and, potentially, for quantitative prediction of molecular weight of GAGs. NMR spectrometry therefore represents a unique analytical method suitable for the simultaneous quantitative control of organic and inorganic composition of crude heparin samples (especially heparin content) as well as an estimation of other physical and quality parameters (molecular weight, animal origin and activity). KW - NMR spectroscopy KW - Heparin KW - Crude heparin KW - USP KW - Ions Y1 - 2022 U6 - https://doi.org/10.1016/j.jpba.2022.114915 SN - 0731-7085 VL - 219 IS - Article number: 114915 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Falkenberg, Fabian A1 - Rahba, Jade A1 - Fischer, David A1 - Bott, Michael A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - Biochemical characterization of a novel oxidatively stable, halotolerant, and high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101T JF - FEBS Open Bio N2 - Halophilic and halotolerant microorganisms represent a promising source of salt-tolerant enzymes suitable for various biotechnological applications where high salt concentrations would otherwise limit enzymatic activity. Considering the current growing enzyme market and the need for more efficient and new biocatalysts, the present study aimed at the characterization of a high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101T. The protease gene was cloned and expressed in Bacillus subtilis DB104. The recombinant protease SPAO with 269 amino acids belongs to the subfamily of high-alkaline subtilisins. The biochemical characteristics of purified SPAO were analyzed in comparison with subtilisin Carlsberg, Savinase, and BPN'. SPAO, a monomer with a molecular mass of 27.1 kDa, was active over a wide range of pH 6.0–12.0 and temperature 20–80 °C, optimally at pH 9.0–9.5 and 55 °C. The protease is highly oxidatively stable to hydrogen peroxide and retained 58% of residual activity when incubated at 10 °C with 5% (v/v) H2O2 for 1 h while stimulated at 1% (v/v) H2O2. Furthermore, SPAO was very stable and active at NaCl concentrations up to 5.0 m. This study demonstrates the potential of SPAO for biotechnological applications in the future. KW - Alkalihalobacillus okhensis KW - detergent protease KW - halotolerant protease KW - high-alkaline subtilisin KW - oxidative stable protease Y1 - 2022 U6 - https://doi.org/10.1002/2211-5463.13457 SN - 2211-5463 N1 - Corresponding author: Petra Siegert VL - 12 IS - 10 SP - 1729 EP - 1746 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Lindner, Simon A1 - Burger, René A1 - Rutledge, Douglas N. A1 - Do, Xuan Tung A1 - Rumpf, Jessica A1 - Diehl, Bernd W. K. A1 - Schulze, Margit A1 - Monakhova, Yulia T1 - Is the calibration transfer of multivariate calibration models between high- and low-field NMR instruments possible? A case study of lignin molecular weight JF - Analytical chemistry N2 - Although several successful applications of benchtop nuclear magnetic resonance (NMR) spectroscopy in quantitative mixture analysis exist, the possibility of calibration transfer remains mostly unexplored, especially between high- and low-field NMR. This study investigates for the first time the calibration transfer of partial least squares regressions [weight average molecular weight (Mw) of lignin] between high-field (600 MHz) NMR and benchtop NMR devices (43 and 60 MHz). For the transfer, piecewise direct standardization, calibration transfer based on canonical correlation analysis, and transfer via the extreme learning machine auto-encoder method are employed. Despite the immense resolution difference between high-field and low-field NMR instruments, the results demonstrate that the calibration transfer from high- to low-field is feasible in the case of a physical property, namely, the molecular weight, achieving validation errors close to the original calibration (down to only 1.2 times higher root mean square errors). These results introduce new perspectives for applications of benchtop NMR, in which existing calibrations from expensive high-field instruments can be transferred to cheaper benchtop instruments to economize. Y1 - 2022 SN - 1520-6882 U6 - https://doi.org/10.1021/acs.analchem.1c05125 VL - 94 IS - 9 SP - 3997 EP - 4004 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Monakhova, Yulia A1 - Diehl, Bernd W.K. T1 - Multinuclear NMR screening of pharmaceuticals using standardization by 2H integral of a deuterated solvent JF - Journal of Pharmaceutical and Biomedical Analysis N2 - NMR standardization approach that uses the 2H integral of deuterated solvent for quantitative multinuclear analysis of pharmaceuticals is described. As a proof of principle, the existing NMR procedure for the analysis of heparin products according to US Pharmacopeia monograph is extended to the determination of Na+ and Cl- content in this matrix. Quantification is performed based on the ratio of a 23Na (35Cl) NMR integral and 2H NMR signal of deuterated solvent, D2O, acquired using the specific spectrometer hardware. As an alternative, the possibility of 133Cs standardization using the addition of Cs2CO3 stock solution is shown. Validation characteristics (linearity, repeatability, sensitivity) are evaluated. A holistic NMR profiling of heparin products can now also be used for the quantitative determination of inorganic compounds in a single analytical run using a single sample. In general, the new standardization methodology provides an appealing alternative for the NMR screening of inorganic and organic components in pharmaceutical products. KW - NMR spectroscopy KW - Inorganic ions KW - Heparin KW - Standardization Y1 - 2022 SN - 0731-7085 U6 - https://doi.org/10.1016/j.jpba.2021.114530 VL - 209 IS - Article number: 114530 PB - Elsevier ER - TY - JOUR A1 - Burger, René A1 - Lindner, Simon A1 - Rumpf, Jessica A1 - Do, Xuan Tung A1 - Diehl, Bernd W.K. A1 - Rehahn, Matthias A1 - Monakhova, Yulia A1 - Schulze, Margit T1 - Benchtop versus high field NMR: Comparable performance found for the molecular weight determination of lignin JF - Journal of Pharmaceutical and Biomedical Analysis N2 - Lignin is a promising renewable biopolymer being investigated worldwide as an environmentally benign substitute of fossil-based aromatic compounds, e.g. for the use as an excipient with antioxidant and antimicrobial properties in drug delivery or even as active compound. For its successful implementation into process streams, a quick, easy, and reliable method is needed for its molecular weight determination. Here we present a method using 1H spectra of benchtop as well as conventional NMR systems in combination with multivariate data analysis, to determine lignin’s molecular weight (Mw and Mn) and polydispersity index (PDI). A set of 36 organosolv lignin samples (from Miscanthus x giganteus, Paulownia tomentosa and Silphium perfoliatum) was used for the calibration and cross validation, and 17 samples were used as external validation set. Validation errors between 5.6% and 12.9% were achieved for all parameters on all NMR devices (43, 60, 500 and 600 MHz). Surprisingly, no significant difference in the performance of the benchtop and high-field devices was found. This facilitates the application of this method for determining lignin’s molecular weight in an industrial environment because of the low maintenance expenditure, small footprint, ruggedness, and low cost of permanent magnet benchtop NMR systems. KW - NMR KW - PLS-regression KW - Molecular weight determination KW - Chemometrics KW - Biomass Y1 - 2022 SN - 0731-7085 U6 - https://doi.org/10.1016/j.jpba.2022.114649 VL - 212 IS - Article number: 114649 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Monakhova, Yulia A1 - Soboleva, Polina M. A1 - Fedotova, Elena S. A1 - Musina, Kristina T. A1 - Burmistrova, Natalia A. T1 - Quantum chemical calculations of IR spectra of heparin disaccharide subunits JF - Computational and Theoretical Chemistry N2 - Heparin is a natural polysaccharide, which plays essential role in many biological processes. Alterations in building blocks can modify biological roles of commercial heparin products, due to significant changes in the conformation of the polymer chain. The variability structure of heparin leads to difficulty in quality control using different analytical methods, including infrared (IR) spectroscopy. In this paper molecular modelling of heparin disaccharide subunits was performed using quantum chemistry. The structural and spectral parameters of these disaccharides have been calculated using RHF/6-311G. In addition, over-sulphated chondroitin sulphate disaccharide was studied as one of the most widespread contaminants of heparin. Calculated IR spectra were analyzed with respect to specific structure parameters. IR spectroscopic fingerprint was found to be sensitive to substitution pattern of disaccharide subunits. Vibrational assignments of calculated spectra were correlated with experimental IR spectral bands of native heparin. Chemometrics was used to perform multivariate analysis of simulated spectral data. KW - IR spectroscopy KW - Chemometrics KW - Quantum chemistry KW - Molecular modelling KW - Quality control Y1 - 2022 SN - 2210-271X U6 - https://doi.org/10.1016/j.comptc.2022.113891 VL - 1217 IS - Article number: 113891 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Monakhova, Yulia A1 - Diehl, Bernd W.K. T1 - Novel approach of qNMR workflow by standardization using 2H integral: Application to any intrinsic calibration standard JF - Talanta N2 - Quantitative nuclear magnetic resonance (qNMR) is routinely performed by the internal or external standardization. The manuscript describes a simple alternative to these common workflows by using NMR signal of another active nuclei of calibration compound. For example, for any arbitrary compound quantification by NMR can be based on the use of an indirect concentration referencing that relies on a solvent having both 1H and 2H signals. To perform high-quality quantification, the deuteration level of the utilized deuterated solvent has to be estimated. In this contribution the new method was applied to the determination of deuteration levels in different deuterated solvents (MeOD, ACN, CDCl3, acetone, benzene, DMSO-d6). Isopropanol-d6, which contains a defined number of deuterons and protons, was used for standardization. Validation characteristics (precision, accuracy, robustness) were calculated and the results showed that the method can be used in routine practice. Uncertainty budget was also evaluated. In general, this novel approach, using standardization by 2H integral, benefits from reduced sample preparation steps and uncertainties, and can be applied in different application areas (purity determination, forensics, pharmaceutical analysis, etc.). KW - qNMR KW - Deuterium NMR KW - Deuterated solvents KW - Standardization Y1 - 2021 SN - 0039-9140 U6 - https://doi.org/10.1016/j.talanta.2020.121504 VL - 222 IS - Article number: 121504 PB - Elsevier ER -