TY - JOUR A1 - Krüger, Götz A1 - Grötzinger, Joachim A1 - Berndt, Heinz T1 - Enantiomeric resolution of amino acid derivatives on chiral stationary phases by high-performance liquid chromatography JF - Journal of Chromatography A Y1 - 1987 U6 - https://doi.org/10.1016/S0021-9673(01)85005-6 SN - 0021-9673 VL - 1987 IS - 397 SP - 223 EP - 232 ER - TY - JOUR A1 - Nokihara, Kiyoshi A1 - Berndt, Heinz T1 - Synthesis of hapten–polypeptide conjugates as antigen models for the N-terminal region of the α-2-chain of rabbit skin collagen JF - Journal of the Royal Society of Chemistry: Perkin Transactions 1 N2 - Synthesis of derivatives of the peptide sequence L-pyroglutamyl-L-phenylalanyl-L-aspartyl-glycyl-L-lysyl-glycyl-glycyl-glycine as the antigenic determinant representing the N-terminal non-helical region of the α-2-chain of rabbit skin collagen, and conjugation to two different polypeptide carriers, are described. Y1 - 1978 U6 - https://doi.org/10.1039/P19780000260 SN - 1364-5463 SN - 0300-922X SN - 1470-4358 VL - 1978 IS - 3 SP - 260 EP - 263 PB - Royal Society of Chemistry CY - Cambridge ER - TY - CHAP A1 - Kroggel, Matthias A1 - Berndt, Heinz ED - Ragnarsson, Ulf T1 - The 0-hydroxiphenyloxicarbonyl-group a new base labile amine protecting group T2 - Peptides 1984 : Proceedings of the 18th European Peptide Symposium Djurönäset, Sweden, June 10 - 15, 1984 Y1 - 1984 SN - 91-22-00715-6 SP - 81 EP - 83 PB - Almquist & Wiksell CY - Stockholm ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Buechel, Sandra A1 - Wolf, C. Roland T1 - Generation and characterization of novel cytochrome P450 Cyp2c gene cluster knockout and CYP2C9 humanized mouse lines JF - Molecular Pharmacology N2 - Compared with rodents and many other animal species, the human cytochrome P450 (P450) Cyp2c gene cluster varies significantly in the multiplicity of functional genes and in the substrate specificity of its enzymes. As a consequence, the use of wild-type animal models to predict the role of human CYP2C enzymes in drug metabolism and drug-drug interactions is limited. Within the human CYP2C cluster CYP2C9 is of particular importance, because it is one of the most abundant P450 enzymes in human liver, and it is involved in the metabolism of a wide variety of important drugs and environmental chemicals. To investigate the in vivo functions of cytochrome P450 Cyp2c genes and to establish a model for studying the functions of CYP2C9 in vivo, we have generated a mouse model with a deletion of the murine Cyp2c gene cluster and a corresponding humanized model expressing CYP2C9 specifically in the liver. Despite the high number of functional genes in the mouse Cyp2c cluster and the reported roles of some of these proteins in different biological processes, mice deleted for Cyp2c genes were viable and fertile but showed certain phenotypic alterations in the liver. The expression of CYP2C9 in the liver also resulted in viable animals active in the metabolism and disposition of a number of CYP2C9 substrates. These mouse lines provide a powerful tool for studying the role of Cyp2c genes and of CYP2C9 in particular in drug disposition and as a factor in drug-drug interaction. Y1 - 2012 U6 - https://doi.org/10.1124/mol.112.080036 SN - 1521-0111 VL - 82 IS - 6 SP - 1022 EP - 1029 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Berndt, Heinz A1 - Krüger, Götz T1 - Resolution of enantiomeric amino acid derivatives by high-performance liquid chromatography on chiral stationary phases JF - Journal of chromatography A Y1 - 1985 U6 - https://doi.org/10.1016/S0021-9673(01)92461-6 SN - 0021-9673 VL - 1985 IS - 348 SP - 275 EP - 279 ER - TY - JOUR A1 - Kuropka, Rolf A1 - Müller, Bettina A1 - Höcker, Hartwig A1 - Berndt, Heinz T1 - Chiral stationary phases via hydrosilylation reaction of N-acryloylamino acids : I. Stationary phase with one chiral centre for high-performance liquid chromatography and development of a new derivatization pattern for amino acid enantiomers JF - Journal of chromatography A Y1 - 1989 SN - 0021-9673 IS - 481 SP - 380 EP - 386 ER - TY - JOUR A1 - Nokihara, Kiyoshi A1 - Berndt, Heinz T1 - Studies on sulfur-containing peptides : tert-butyloxycarbonylsulfenyl and benzyloxycarbonylsulfenyl derivatives as protecting groups for cysteine JF - The journal of organic chemistry Y1 - 1978 U6 - https://doi.org/10.1021/jo00419a046 SN - 0022-3263 VL - 43 IS - 25 SP - 4893 EP - 4895 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Kalbe, Jochen A1 - Höcker, Hartwig A1 - Berndt, Heinz T1 - Design of enzyme reactors as chromatographic columns for racemic resolution of amino acid esters JF - Chromatographia Y1 - 1989 SN - 0009-5893 U6 - https://doi.org/10.1007/BF02319646 VL - 28 IS - 3-4 SP - 193 EP - 196 ER - TY - JOUR A1 - Danho, Waleed A1 - Naithani, Vinod K. A1 - Sasaki, André N. A1 - Föhles, Joseph A1 - Berndt, Heinz A1 - Büllesbach, Erika E. A1 - Zahn, H. T1 - Human proinsulin, VII : synthesis of two protected peptides corresponding to the sequences 1—45 and 46—86 of the prohormone JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1980 U6 - https://doi.org/10.1515/bchm2.1980.361.1.857 SN - 1437-4315 SN - 0018-4888 VL - 361 IS - 1 SP - 857 EP - 863 ER - TY - JOUR A1 - Kalbe, Jochen A1 - Kuropka, Rolf A1 - Meyer-Stork, L. Sebastian A1 - Berndt, Heinz A1 - Sauter, Sybille L. A1 - Loss, Peter A1 - Hendo, Karsten A1 - Riesner, Detlev A1 - Höcker, Hartwig T1 - Isolation and characterization of high-molecular mass DNA from hair shafts JF - Biological chemistry Y1 - 1988 SN - 0177-3593 U6 - https://doi.org/10.1515/bchm3.1988.369.1.413 VL - 369 IS - 1 SP - 413 EP - 416 ER - TY - JOUR A1 - Baumann, Marcus A1 - Tillmann, Urban A1 - Aletsee, Ludwig T1 - Distribution of Carbon Among Photosynthetic End Products in the Bloom-Forming Arctic Diatom Thalassiosira antarctica COMBER / Tillmann, U. ; Baumann, M.E.M. ; Aletsee, L. JF - Polar Biology. 10 (1989), H. 3 Y1 - 1989 SN - 0722-4060 SP - 231 EP - 238 ER - TY - CHAP A1 - Al-Kaidy, Huschyar A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - A platform technology for the automated reaction control in magnetizable micro-fluidic droplets T2 - Biomaterials - made in bioreactors : book of abstracts, May 26 - 28, 2014, Radisson Blu Park Hotel and Conference Dentre, Radebeul, Germany Y1 - 2014 SP - 21 EP - 22 PB - DECHEMA CY - Frankfurt am Main ER - TY - JOUR A1 - Ribitsch, Doris A1 - Heumann, Sonja A1 - Karl, Wolfgang A1 - Gerlach, Jochen A1 - Leber, Regina A1 - Birner-Gruenberger, Ruth A1 - Gruber, Karl A1 - Eiteljoerg, Inge A1 - Remler, Peter A1 - Siegert, Petra A1 - Lange, Jennifer A1 - Maurer, Karl-Heinz A1 - Berg, Gabriele A1 - Guebitz, G. M. A1 - Schwab, H. T1 - Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli JF - Journal of biotechnology N2 - 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. KW - Alginate beads KW - Stenotrophomonas maltophilia KW - Detergent protease Y1 - 2012 U6 - https://doi.org/10.1016/j.jbiotec.2011.09.025 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 157 IS - 1 SP - 140 EP - 147 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Srivastava, Alok A1 - Singh, Virendra A1 - Aggarwal, Pranav A1 - Schneeweiss, F. A1 - Scherer, Ulrich W. A1 - Friedrich, W. T1 - Optical studies of insulating polymers for radiation dose monitoring JF - Indian Journal of Pure and Applied Physics N2 - The optical study carried out on insulating polymers namely polyethyleneterephthalate (PET) and polyvinylchloride (PVC) has been described. The polymers are exposed to different radiation doses by exposing them to swift heavy ions of carbon (90 MeV), silicon (120 MeV) and nickel (100 MeV) which influence on their optical properties. The studies show that amongst the investigated polymers, PVC and PET have potential for application as dosimeter beyond a threshold dose which is strongly dependent on the nature of the material and the radiation type. The optical micrographs show a distinct change in colour of the sample with increase in radiation dose. Y1 - 2010 SN - 0019-5596 N1 - Special Issue: SI VL - 48 IS - 11 SP - 782 EP - 786 PB - Council Of Scientific And Industrial Research (CSIR), National Institute Of Science Communication and Policy Research (NIScPR) CY - New Delhi ER - TY - CHAP A1 - Engel, Mareike A1 - Thieringer, Julia A1 - Tippkötter, Nils T1 - Linking bioprocess engineering and electrochemistry for sustainable biofuel production T2 - Young Researchers Symposium, YRS 2016. Proceedings N2 - Electromicrobial engineering is an emerging, highly interdisciplinary research area linking bioprocesses with electrochemistry. In this work, microbial electrosynthesis (MES) of biobutanol is carried out during acetone-butanol-ethanol (ABE) fermentations with Clostridium acetobutylicum. A constant electric potential of −600mV (vs. Ag/AgCl) with simultaneous addition of the soluble redox mediator neutral red is used in order to study the electron transfer between the working electrode and the bacterial cells. The results show an earlier initiation of solvent production for all fermentations with applied potential compared to the conventional ABE fermentation. The f inal butanol concentration can be more than doubled by the application of a negative potential combined with addition of neutral red. Moreover a higher biofilm formation on the working electrode compared to control cultivations has been observed. In contrast to previous studies, our results also indicate that direct electron transfer (DET) might be possible with C. acetobutylicum. The presented results make microbial butanol production economically attractive and therefore support the development of sustainable production processes in the chemical industry aspired by the “Centre for resource-efficient chemistry and raw material change” as well as the the project “NanoKat” working on nanostructured catalysts in Kaiserslautern. Y1 - 2016 N1 - Young Researchers Symposium, YRS 2016, 14th - 15th April 2016, Fraunhofer-Zentrum Kaiserslautern SP - 49 EP - 53 PB - Fraunhofer Verlag CY - Karlsruhe ER - TY - JOUR A1 - Oehlenschläger, Katharina A1 - Volkmar, Marianne A1 - Stiefelmaier, Judith A1 - Langsdorf, Alexander A1 - Holtmann, Dirk A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum JF - Applied Microbiology and Biotechnology N2 - Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured. KW - Pre-culture KW - Metabolic shift KW - Acid crash KW - C. acetobutylicum KW - ABE KW - Butanol Y1 - 2024 U6 - https://doi.org/10.1007/s00253-023-12981-8 SN - 1432-0614 VL - 108 PB - Springer CY - Berlin, Heidelberg ER - TY - JOUR A1 - Hengsbach, Jan-Niklas A1 - Engel, Mareike A1 - Cwienczek, Marcel A1 - Stiefelmaier, Judith A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Scalable unseparated bioelectrochemical reactors by using a carbon fiber brush as stirrer and working electrode JF - ChemElectroChem N2 - The concept of energy conversion into platform chemicals using bioelectrochemical systems (BES) has gained increasing attention in recent years, as the technology simultaneously provides an opportunity for sustainable chemical production and tackles the challenge of Power-to-X technologies. There are many approaches to realize the industrial scale of BES. One concept is to equip standard bioreactors with static electrodes. However, large installations resulted in a negative influence on various reactor parameters. In this study, we present a new single-chamber BES based on a stirred tank reactor in which the stirrer was replaced by a carbon fiber brush, performing the functions of the working electrode and the stirrer. The reactor is characterized in abiotic studies and electro-fermentations with Clostridium acetobutylicum. Compared to standard reactors an increase in butanol production of 20.14±3.66 % shows that the new BES can be efficiently used for bioelectrochemical processes. Y1 - 2023 U6 - https://doi.org/10.1002/celc.202300440 SN - 2196-0216 VL - 10 IS - 21 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Haeger, Gerrit A1 - Probst, Johanna A1 - Jaeger, Karl-Erich A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - Novel aminoacylases from Streptomyces griseus DSM 40236 and their recombinant production in Streptomyces lividans JF - FEBS Open Bio N2 - Amino acid-based surfactants are valuable compounds for cosmetic formulations. The chemical synthesis of acyl-amino acids is conventionally performed by the Schotten-Baumann reaction using fatty acyl chlorides, but aminoacylases have also been investigated for use in biocatalytic synthesis with free fatty acids. Aminoacylases and their properties are diverse; they belong to different peptidase families and show differences in substrate specificity and biocatalytic potential. Bacterial aminoacylases capable of synthesis have been isolated from Burkholderia, Mycolicibacterium, and Streptomyces. Although several proteases and peptidases from S. griseus have been described, no aminoacylases from this species have been identified yet. In this study, we investigated two novel enzymes produced by S. griseus DSM 40236ᵀ . We identified and cloned the respective genes and recombinantly expressed an α-aminoacylase (EC 3.5.1.14), designated SgAA, and an ε-lysine acylase (EC 3.5.1.17), designated SgELA, in S. lividans TK23. The purified aminoacylase SgAA was biochemically characterized, focusing on its hydrolytic activity to determine temperature- and pH optima and stabilities. The aminoacylase could hydrolyze various acetyl-amino acids at the Nα -position with a broad specificity regarding the sidechain. Substrates with longer acyl chains, like lauroyl-amino acids, were hydrolyzed to a lesser extent. Purified aminoacylase SgELA specific for the hydrolysis of Nε -acetyl-L-lysine was unstable and lost its enzymatic activity upon storage for a longer period but could initially be characterized. The pH optimum of SgELA was pH 8.0. While synthesis of acyl-amino acids was not observed with SgELA, SgAA catalyzed the synthesis of lauroyl-methionine. KW - Streptomyces lividans KW - recombinant expression KW - Streptomyces griseus KW - ε-lysine acylase KW - α-aminoacylase Y1 - 2023 U6 - https://doi.org/10.1002/2211-5463.13723 SN - 2211-5463 N1 - Corresponding author: Petra Siegert VL - 13 IS - 12 SP - 2224 EP - 2238 PB - Wiley CY - Hoboken, NJ ER - TY - GEN A1 - Duwe, A. A1 - Schlegel, C. A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Sequentielle Extraktion von Cellulose zur effizienten Nutzung der Stoffströme in der Holzbioraffinerie T2 - Chemie Ingenieur Technik N2 - In der Reihe der nachwachsenden Rohstoffe besitzt Holz als erneuerbare und umweltfreundliche Ressource ein großes Potenzial. Über 11 Mio. ha Holz, das laut der Fachagentur für nachwachsende Rohstoffe (FNR) auch für industrielle Zwecke genutzt werden kann, wuchsen im Jahr 2013 allein auf bundesdeutscher Fläche. 56,8 Mio. m³ jährlicher Holzeinschlag in den letzten zehn Jahren wurde zu knapp der Hälfte stofflich und der Rest energetisch verwertet. Im Rahmen dieser Arbeit konnte auf der Basis vom Holz der Buche, die nach Fichte und Kiefer die dritthäufigste Baumart in Deutschland ist und 15% der deutschen Waldfläche ausmacht, die Fraktionierung der polymeren Hauptbestandteile mit niedrigem energetischen Einsatz erreicht werden. Hierbei werden in einem nachgeschalteten Extraktionsprozess die beiden Komponenten Hemicellulose und Lignin in flüssiger Form von der finalen festen Cellulosefraktion abgetrennt. Die Extraktion der Hemicellulose erfolgt durch eine Liquid Hot Water (LHW)-Behandlung. Untersucht wird der katalytische Zusatz anorganischer Säuren wie H₃PO₄ und H₂SO₄. Im Hinblick auf die weitere Verwertung von Lignin zu aromatischen Synthesebausteinen kommt die Organosolv-Extraktion mit einem Ethanol/Wasser-Gemisch zum Einsatz. Von Vorteil ist die weitere Verwendung beider Stoffströme ohne Fällungsschritt und nachteiliger Verdünnung der Hemicellulose. Y1 - 2014 U6 - https://doi.org/10.1002/cite.201450308 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung 2014 und 31. DECHEMA-Jahrestagung der Biotechnologen, 30. September - 2. Oktober 2014, Eurogress Aachen VL - 86 IS - 9 SP - 1400 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Möhring, S. A1 - Wulfhorst, H. A1 - Capitain, C. A1 - Roth, J. A1 - Tippkötter, Nils T1 - Fractioning of lignocellulosic biomass: Scale-down and automation of thermal pretreatment for parameter optimization T2 - Chemie Ingenieur Technik N2 - In order to efficiently convert lignocellulose, it is often necessary to conduct a pretreatment. The biomass considered in this study typically comprises of agricultural and horticultural residues, as well as beechwood. A very environmentally friendly method, namely, fungal pretreatment using white-rot fungi, leads to an enhanced enzymatic hydrolysis. In contrast to other processes presented, the energy input is extremely low. However, the fungal growth on the lignocellulosic substrates takes several weeks at least in order to be effective. Thus, the reduction of chemicals and energy for thermal processing is a target of our current research. Liquid hot water (LHW) and solvent-based pretreatment (OrganoSolv) require more complex equipment, as they depend on high temperatures (160 – 180 °C) and enhanced pressure (up to 20 bar). However, they prove to be promising processes in regard to the fractioning of lignocellulose. For optimal lignin recovery the parameters differ from those established in cellulose extraction. A novel screening system scaled down to a reaction volume of 100 mL has been developed and successfully tested for this purpose. Y1 - 2016 U6 - https://doi.org/10.1002/cite.201650288 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung und 32. DECHEMA-Jahrestagung der Biotechnologen 2016, 12. - 15. September 2016, Eurogress Aachen VL - 88 IS - 9 SP - 1229 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Welden, Melanie A1 - Severins, Robin A1 - Poghossian, Arshak A1 - Wege, Christina A1 - Bongaerts, Johannes A1 - Siegert, Petra A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor JF - Chemosensors N2 - 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. Y1 - 2022 U6 - https://doi.org/10.3390/chemosensors10060218 SN - 2227-9040 N1 - This article belongs to the Special Issue "Nanostructured Devices for Biochemical Sensing" VL - 10 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Welden, Rene A1 - Jablonski, Melanie A1 - Wege, Christina A1 - Keusgen, Michael A1 - Wagner, Patrick Hermann A1 - Wagner, Torsten A1 - Schöning, Michael Josef T1 - Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase JF - Biosensors N2 - The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS. KW - microfluidics KW - enzyme kinetics KW - actuator-sensor system KW - light-addressable electrode KW - light-addressable potentiometric sensor Y1 - 2021 U6 - https://doi.org/10.3390/bios11060171 SN - 2079-6374 N1 - This article belongs to the Special Issue "Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)" VL - 11 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Welden, Melanie A1 - Poghossian, Arshak A1 - Vahidpour, Farnoosh A1 - Wendlandt, Tim A1 - Keusgen, Michael A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Towards multi-analyte detection with field-effect capacitors modified with tobacco mosaic virus bioparticles as enzyme nanocarriers JF - Biosensors N2 - Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO₂-Ta₂O₅ layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1–3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta₂O₅-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate. KW - urease KW - enzyme-logic gate KW - bi-enzyme biosensor KW - capacitive field-effect sensor KW - tobacco mosaic virus (TMV) KW - penicillinase Y1 - 2022 U6 - https://doi.org/10.3390/bios12010043 SN - 2079-6374 N1 - This article belongs to the Special Issue "Biosensors: 10th Anniversary Feature Papers" VL - 12 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Zhantlessova, Sirina A1 - Savitskaya, Irina A1 - Kistaubayeva, Aida A1 - Ignatova, Ludmila A1 - Talipova, Aizhan A1 - Pogrebnjak, Alexander A1 - Digel, Ilya T1 - Advanced “Green” prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy JF - Polymers N2 - Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for “grafting” of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality. KW - coculture KW - pullulan KW - exopolysaccharides KW - prebiotic KW - bacterial cellulose Y1 - 2022 U6 - https://doi.org/10.3390/polym14153224 SN - 2073-4360 N1 - This article belongs to the Special Issue "Cellulose Based Composites" VL - 14 IS - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hafidi, Youssef A1 - El Hatka, Hicham A1 - Schmitz, Dominik A1 - Krauss, Manuel A1 - Pettrak, Jürgen A1 - Biel, Markus A1 - Ittobane, Najim T1 - Sustainable soil additives for water and micronutrient supply: swelling and chelating properties of polyaspartic acid hydrogels utilizing newly developed crosslinkers JF - Gels N2 - Drought and water shortage are serious problems in many arid and semi-arid regions. This problem is getting worse and even continues in temperate climatic regions due to climate change. To address this problem, the use of biodegradable hydrogels is increasingly important for the application as water-retaining additives in soil. Furthermore, efficient (micro-)nutrient supply can be provided by the use of tailored hydrogels. Biodegradable polyaspartic acid (PASP) hydrogels with different available (1,6-hexamethylene diamine (HMD) and L-lysine (LYS)) and newly developed crosslinkers based on diesters of glycine (GLY) and (di-)ethylene glycol (DEG and EG, respectively) were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) and regarding their swelling properties (kinetic, absorbency under load (AUL)) as well as biodegradability of PASP hydrogel. Copper (II) and zinc (II), respectively, were loaded as micronutrients in two different approaches: in situ with crosslinking and subsequent loading of prepared hydrogels. The results showed successful syntheses of di-glycine-ester-based crosslinkers. Hydrogels with good water-absorbing properties were formed. Moreover, the developed crosslinking agents in combination with the specific reaction conditions resulted in higher water absorbency with increased crosslinker content used in synthesis (10% vs. 20%). The prepared hydrogels are candidates for water-storing soil additives due to the biodegradability of PASP, which is shown in an exemple. The incorporation of Cu(II) and Zn(II) ions can provide these micronutrients for plant growth. KW - micronutrients KW - swelling properties KW - biodegradable polymers KW - hydrogels KW - superabsorbent polymers KW - glycine KW - polyaspartic acid Y1 - 2024 U6 - https://doi.org/10.3390/gels10030170 SN - 2310-2861 VL - 10 IS - 3 SP - Artikel 170 PB - MDPI CY - Basel ER - TY - JOUR A1 - El Bergui, Omnia A1 - Abouabdillah, Aziz A1 - Bourioug, Mohamed A1 - Schmitz, Dominik A1 - Biel, Markus A1 - Aboudrare, Abdellah A1 - Krauss, Manuel A1 - Jomaa, Ahlem A1 - Romuli, Sebastian A1 - Müller, Joachim A1 - Fagroud, Mustapha A1 - Bouabid, Rachid T1 - Innovative solutions for drought: Evaluating hydrogel application on onion cultivation (Allium cepa) in Morocco JF - Water N2 - Throughout the last decade, and particularly in 2022, water scarcity has become a critical concern in Morocco and other Mediterranean countries. The lack of rainfall during spring was worsened by a succession of heat waves during the summer. To address this drought, innovative solutions, including the use of new technologies such as hydrogels, will be essential to transform agriculture. This paper presents the findings of a study that evaluated the impact of hydrogel application on onion (Allium cepa) cultivation in Meknes, Morocco. The treatments investigated in this study comprised two different types of hydrogel-based soil additives (Arbovit® polyacrylate and Huminsorb® polyacrylate), applied at two rates (30 and 20 kg/ha), and irrigated at two levels of water supply (100% and 50% of daily crop evapotranspiration; ETc). Two control treatments were included, without hydrogel application and with both water amounts. The experiment was conducted in an open field using a completely randomized design. The results indicated a significant impact of both hydrogel-type dose and water dose on onion plant growth, as evidenced by various vegetation parameters. Among the hydrogels tested, Huminsorb® Polyacrylate produced the most favorable outcomes, with treatment T9 (100%, HP, 30 kg/ha) yielding 70.55 t/ha; this represented an increase of 11 t/ha as compared to the 100% ETc treatment without hydrogel application. Moreover, the combination of hydrogel application with 50% ETc water stress showed promising results, with treatment T4 (HP, 30 kg, 50%) producing almost the same yield as the 100% ETc treatment without hydrogel while saving 208 mm of water. KW - water economy KW - yield KW - deficit irrigation KW - hydrogel KW - onion Y1 - 2023 U6 - https://doi.org/10.3390/w15111972 VL - 15 IS - 11 PB - MDPI CY - Basel ER - TY - GEN A1 - Roth, J. A1 - Tippkötter, Nils T1 - New Approach for Enzymatic Hydrolysis of Lignocellulose with Selective Diffusion Separation of the Monosaccharide Products T2 - Chemie Ingenieur Technik N2 - Enzymatic hydrolysis of lignocellulosic material plays an important role in the classical biorefinery approach. Apart from the pretreatment of the raw material, hydrolysis is the basis for the conversion of the cellulose and hemicellulose fraction into fermentable sugars. After hydrolysis, usually a solid-liquid separation takes place, in order to separate the residual plant material from the sugar-rich fraction, which can be subsequently used in a fermentation step. In order to factor out the separation step, the usage of in alginate immobilized crude cellulose fiber beads (CFBs) were evaluated. Pretreated cellulose fibers are incorporated in an alginate matrix together with the relevant enzymes. In doing so, sugars diffuse trough the alginate matrix, allowing a simplified delivery into the surrounding fluid. This again reduces product inhibition of the glucose on the enzyme catalysts. By means of standardized bead production the hydrolysis in lab scale was possible. First results show that liberation of glucose and xylose is possible, allowing a maximum total sugar yield of 75 %. Y1 - 2016 U6 - https://doi.org/10.1002/cite.201650301 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 - 1237 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Rezension zu: Encyclopedia of Industrial Biotechnology, Vol. 1–7. By MC Flickinger. JF - Chemie Ingenieur Technik Y1 - 2012 U6 - https://doi.org/10.1002/cite.201290052 SN - 0009-286X SN - 1522-2640 (eISSN) VL - 6 IS - 84 SP - 936 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Falkenberg, Fabian A1 - Bott, Michael A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - Phylogenetic survey of the subtilase family and a data-mining-based search for new subtilisins from Bacillaceae JF - Frontiers in Microbiology N2 - The subtilase family (S8), a member of the clan SB of serine proteases are ubiquitous in all kingdoms of life and fulfil different physiological functions. Subtilases are divided in several groups and especially subtilisins are of interest as they are used in various industrial sectors. Therefore, we searched for new subtilisin sequences of the family Bacillaceae using a data mining approach. The obtained 1,400 sequences were phylogenetically classified in the context of the subtilase family. This required an updated comprehensive overview of the different groups within this family. To fill this gap, we conducted a phylogenetic survey of the S8 family with characterised holotypes derived from the MEROPS database. The analysis revealed the presence of eight previously uncharacterised groups and 13 subgroups within the S8 family. The sequences that emerged from the data mining with the set filter parameters were mainly assigned to the subtilisin subgroups of true subtilisins, high-alkaline subtilisins, and phylogenetically intermediate subtilisins and represent an excellent source for new subtilisin candidates. Y1 - 2022 U6 - https://doi.org/10.3389/fmicb.2022.1017978 SN - 1664-302X VL - 2022 IS - 13 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Haeger, Gerrit A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent JF - Analytical Biochemistry N2 - 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. Y1 - 2022 U6 - https://doi.org/10.1016/j.ab.2022.114819 SN - 1096-0309 IS - 624 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Falkenberg, Fabian A1 - Voß, Leonie A1 - Bott, Michael A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - New robust subtilisins from halotolerant and halophilic Bacillaceae JF - Applied Microbiology and Biotechnology N2 - The aim of the present study was the characterisation of three true subtilisins and one phylogenetically intermediate subtilisin from halotolerant and halophilic microorganisms. Considering the currently growing enzyme market for efficient and novel biocatalysts, data mining is a promising source for novel, as yet uncharacterised enzymes, especially from halophilic or halotolerant Bacillaceae, which offer great potential to meet industrial needs. Both halophilic bacteria Pontibacillus marinus DSM 16465ᵀ and Alkalibacillus haloalkaliphilus DSM 5271ᵀ and both halotolerant bacteria Metabacillus indicus DSM 16189 and Litchfieldia alkalitelluris DSM 16976ᵀ served as a source for the four new subtilisins SPPM, SPAH, SPMI and SPLA. The protease genes were cloned and expressed in Bacillus subtilis DB104. Purification to apparent homogeneity was achieved by ethanol precipitation, desalting and ion-exchange chromatography. Enzyme activity could be observed between pH 5.0–12.0 with an optimum for SPPM, SPMI and SPLA around pH 9.0 and for SPAH at pH 10.0. The optimal temperature for SPMI and SPLA was 70 °C and for SPPM and SPAH 55 °C and 50 °C, respectively. All proteases showed high stability towards 5% (w/v) SDS and were active even at NaCl concentrations of 5 M. The four proteases demonstrate potential for future biotechnological applications. KW - Biotechnological application KW - Bacillaceae KW - Subtilisin KW - Subtilases KW - Halotolerant protease Y1 - 2023 U6 - https://doi.org/10.1007/s00253-023-12553-w SN - 1432-0614 N1 - Corresponding author: Petra Siegert VL - 107 SP - 3939 EP - 3954 PB - Springer Nature CY - Berlin ER - TY - GEN A1 - Braun, Lena A1 - Krafft, Simone A1 - Tippkötter, Nils T1 - Combined supercritical carbon dioxide extraction and chromatography of the algae fatty linoleic and linolenic acid T2 - Chemie Ingenieur Technik N2 - A method for the integrated extraction and separation of fatty acids from algae using supercritical CO2 is presented. Desmodesmus obliquus and Chlorella sorokiniana were used as algae. First, a method for chromatographic separation of fatty acids of different degrees of saturation was established and optimized. Then, an integrated method for supercritical extraction was developed for both algal species. It was also verified whether prior cell disruption was beneficial for extraction. In developing the method for chromatographic separation, statistical experimental design was used to determine the optimal parameter settings. The methanol content in the mobile phase proved to be the most important parameter for successful separation of the three unsaturated fatty acids oleic acid, linoleic acid, and linolenic acid. Supercritical extraction with dried algae showed that about four times more fatty acids can be extracted from C. sorokiniana relative to the dry mass used. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255308 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1304 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Penner, Crystal A1 - Usherovich, Samuel A1 - Niedermeier, Jana A1 - Bélanger-Champagne, Camille A1 - Trinczek, Michael A1 - Paulßen, Elisabeth A1 - Hoehr, Cornelia T1 - Organic Scintillator-Fibre Sensors for Proton Therapy Dosimetry: SCSF-3HF and EJ-260 JF - electronics N2 - In proton therapy, the dose from secondary neutrons to the patient can contribute to side effects and the creation of secondary cancer. A simple and fast detection system to distinguish between dose from protons and neutrons both in pretreatment verification as well as potentially in vivo monitoring is needed to minimize dose from secondary neutrons. Two 3 mm long, 1 mm diameter organic scintillators were tested for candidacy to be used in a proton–neutron discrimination detector. The SCSF-3HF (1500) scintillating fibre (Kuraray Co. Chiyoda-ku, Tokyo, Japan) and EJ-260 plastic scintillator (Eljen Technology, Sweetwater, TX, USA) were irradiated at the TRIUMF Neutron Facility and the Proton Therapy Research Centre. In the proton beam, we compared the raw Bragg peak and spread-out Bragg peak response to the industry standard Markus chamber detector. Both scintillator sensors exhibited quenching at high LET in the Bragg peak, presenting a peak-to-entrance ratio of 2.59 for the EJ-260 and 2.63 for the SCSF-3HF fibre, compared to 3.70 for the Markus chamber. The SCSF-3HF sensor demonstrated 1.3 times the sensitivity to protons and 3 times the sensitivity to neutrons as compared to the EJ-260 sensor. Combined with our equations relating neutron and proton contributions to dose during proton irradiations, and the application of Birks’ quenching correction, these fibres provide valid candidates for inexpensive and replicable proton-neutron discrimination detectors Y1 - 2022 U6 - https://doi.org/10.3390/electronics12010011 SN - 2079-9292 N1 - This article belongs to the Special Issue "Applications of Optical Fiber Sensors" VL - 12 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Niedermeier, Jana A1 - Penner, Crystal A1 - Usherovich, Samuel A1 - Bélanger-Champagne, Camille A1 - Paulßen, Elisabeth A1 - Hoehr, Cornelia T1 - Optical Fibers as Dosimeter Detectors for Mixed Proton/Neutron Fields - A Biological Dosimeter JF - electronics N2 - In recent years, proton therapy has gained importance as a cancer treatment modality due to its conformality with the tumor and the sparing of healthy tissue. However, in the interaction of the protons with the beam line elements and patient tissues, potentially harmful secondary neutrons are always generated. To ensure that this neutron dose is as low as possible, treatment plans could be created to also account for and minimize the neutron dose. To monitor such a treatment plan, a compact, easy to use, and inexpensive dosimeter must be developed that not only measures the physical dose, but which can also distinguish between proton and neutron contributions. To that end, plastic optical fibers with scintillation materials (Gd₂O₂S:Tb, Gd₂O₂S:Eu, and YVO₄:Eu) were irradiated with protons and neutrons. It was confirmed that sensors with different scintillation materials have different sensitivities to protons and neutrons. A combination of these three scintillators can be used to build a detector array to create a biological dosimeter. KW - biological dosimeter KW - Bragg peak KW - relative dosimetry KW - optical fibers KW - proton therapy KW - protons KW - neutrons Y1 - 2023 U6 - https://doi.org/10.3390/electronics12020324 SN - 2079-9292 N1 - This article belongs to the Special Issue "Applications of Optical Fiber Sensors" VL - 12 IS - 2 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ojovan, Michael I. A1 - Steinmetz, Hans-Jürgen T1 - Approaches to Disposal of Nuclear Waste JF - Energies N2 - We present a concise mini overview on the approaches to the disposal of nuclear waste currently used or deployed. The disposal of nuclear waste is the end point of nuclear waste management (NWM) activities and is the emplacement of waste in an appropriate facility without the intention to retrieve it. The IAEA has developed an internationally accepted classification scheme based on the end points of NWM, which is used as guidance. Retention times needed for safe isolation of waste radionuclides are estimated based on the radiotoxicity of nuclear waste. Disposal facilities usually rely on a multi-barrier defence system to isolate the waste from the biosphere, which comprises the natural geological barrier and the engineered barrier system. Disposal facilities could be of a trench type, vaults, tunnels, shafts, boreholes, or mined repositories. A graded approach relates the depth of the disposal facilities’ location with the level of hazard. Disposal practices demonstrate the reliability of nuclear waste disposal with minimal expected impacts on the environment and humans. KW - borehole disposal KW - geological disposal KW - disposal facility KW - retention time KW - nuclear waste Y1 - 2022 U6 - https://doi.org/10.3390/en15207804 SN - 1996-1073 N1 - This article belongs to the Special Issue "Treatment of Radioactive Waste and Sustainability Energy" VL - 15 IS - 20 PB - MDPI CY - Basel ER - TY - JOUR A1 - Riepl, Herbert Matthias A1 - Pettrak, Jürgen A1 - Faulstich, Martin A1 - Herrmann, Wolfgang Anton T1 - Self metathesis of fatty alcohols and amines to provide monomers for polyester and polyamide products JF - Macromolecular Symposia N2 - Self metathesis of oleochemicals offers a variety of bifunctional compounds, that can be used as monomer for polymer production. Many precursors are in huge scales available, like oleic acid ester (biodiesel), oleyl alcohol (tensides), oleyl amines (tensides, lubricants). We show several ways to produce and separate and purify C18-α,ω-bifunctional compounds, using Grubbs 2nd Generation catalysts, starting from technical grade educts. KW - fatty acid KW - metathesis KW - polyamide KW - polyester KW - renewable resources Y1 - 2010 U6 - https://doi.org/10.1002/masy.200900041 SN - 1521-3900 (eISSN) SN - 0258-0322 SN - 1022-1360 N1 - Special Issue: "Olefin Metathesis" VL - 293 IS - 1 SP - 39 EP - 42 PB - Wiley-VCH CY - Weinheim 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 J. 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 - Aggarwal, Pranav A1 - Dhiman, Shashi K. A1 - Kumar, G. A1 - Scherer, Ulrich W. A1 - Singla, M. L. A1 - Srivastava, Alok T1 - Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose JF - Indian Journal of Pure and Applied Physics N2 - Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions. Y1 - 2012 SN - 0019-5596 VL - 50 IS - 2 SP - 129 EP - 132 PB - Council Of Scientific And Industrial Research (CSIR), National Institute Of Science Communication and Policy Research (NIScPR) CY - New Delhi 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 - Baumann, Marcus A1 - Lara, R.J. A1 - Hubberten, D.N. A1 - Thomas, D. N. T1 - Dissolved organic matter studies in enclosed systems: Application of hydophobic fractionation for the assessment of organic nitrogen dynamics / Lara, R.J. ; Hubberten, U. ; Thomas, D.N. ; Baumann, M.E.M. ; Kattner, G. JF - Journal of Marine Systems. 13 (1997), H. 1-4 Y1 - 1997 SN - 0924-7963 SP - 155 EP - 161 ER - TY - JOUR A1 - Baumann, Marcus A1 - Thomas, D. N. A1 - Gleitz, M. T1 - Efficiency of carbon assimilation and photoacclimation in a small unicellular Chaetoceros species from the Weddel Sea (Antarctica): Influence of temperature and irridiance / Thomas, D. ; Baumann, M.E.M. ; Gleitz, M. JF - Journal of Experimental Marine Biology and Ecology. 157 (1992), H. 2 Y1 - 1992 SN - 0022-0981 SP - 195 EP - 209 ER - TY - JOUR A1 - Bode, Jürgen A1 - Bartsch, Jörg W. A1 - Boulikas, Toulikas A1 - Iber, Michaela A1 - Mielke, Christian A1 - Schübeler, Dirk A1 - Seibler, Jost A1 - Benham, Craig T1 - Transcription-promoting genomic sites in mammalia: their elucidation and architectural principles JF - Gene therapy & molecular biology Y1 - 1998 SN - 1529-9120 VL - 1 IS - 1 SP - 1 EP - 29 ER - TY - JOUR A1 - Mang, Thomas A1 - Hodenius, Michael A. J. A1 - Schmitz-Rode, Thomas A1 - Baumann, Martin A1 - Ivanova, Gergana A1 - Wong, John Erik A1 - Haulena, Friedhelm A1 - Soenen, Stefaan J. H. A1 - de Cuyper, Marcel T1 - Absorption of 10-hydroxycamptothecin into the coat of magnetoliposomes / Hodenius, M. A. J. ; Schmitz-Rode, T. ; Baumann, M. ; Ivoanova, G. ; Wong, J. E. ; Mang, T. ; Haulena, F. ; Soenen, S. J. H. ; De Cuyper, M. JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects. 343 (2009), H. 1-3 Y1 - 2009 SN - 0927-7757 N1 - Colloid and Surface Science for Nanotechnology SP - 20 EP - 23 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Balakrishnan, Karthikeyan A1 - Andrei-Selmer, Luminita-Cornelia A1 - Selmer, Thorsten A1 - Bacher, Michael A1 - Dodel, Richard T1 - Comparison of intravenous immunoglobulins for naturally occurring autoantibodies against amyloid-β JF - Journal of Alzheimer's Disease N2 - Intravenous immunoglobulins (IVIG) are currently used for therapeutic purposes in autoimmune disorders. Recently, we demonstrated the presence of naturally occurring antibodies against amyloid- β (nAbs-Aβ) within the pool of IVIG. In this study, we compared different brands of IVIG for nAbs-Aβ and have found differences in the specificity of the nAbs-Aβ towards Aβ1–40 and Aβ1–42 . We analyzed the influence of a pH-shift over the course of antibody storage using ELISA and investigated antibody dimerization at acidic and neutral pH as well as differences in the IgG subclass distributions among the IVIG using both HPLC and a nephelometric assay. Furthermore, we investigated the epitope region of purified nAbs-Aβ. The differences found in Aβ specificity are not directly proportionate to the binding nature of these antibodies when administered in vivo. This information, however, may serve as a guide when choosing the commercial source of IVIG for therapeutic applications in Alzheimer's disease Y1 - 2010 U6 - https://doi.org/10.3233/JAD-2010-1353 SN - 1387-2877 VL - 20 IS - 1 SP - 135 EP - 143 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Tix, Julian A1 - Moll, Fabian A1 - Krafft, Simone A1 - Betsch, Matthias A1 - Tippkötter, Nils T1 - Hydrogen production from enzymatic pretreated organic waste with thermotoga neapolitana JF - Energies N2 - Biomass from various types of organic waste was tested for possible use in hydrogen production. The composition consisted of lignified samples, green waste, and kitchen scraps such as fruit and vegetable peels and leftover food. For this purpose, the enzymatic pretreatment of organic waste with a combination of five different hydrolytic enzymes (cellulase, amylase, glucoamylase, pectinase and xylase) was investigated to determine its ability to produce hydrogen (H2) with the hydrolyzate produced here. In course, the anaerobic rod-shaped bacterium T. neapolitana was used for H2 production. First, the enzymes were investigated using different substrates in preliminary experiments. Subsequently, hydrolyses were carried out using different types of organic waste. In the hydrolysis carried out here for 48 h, an increase in glucose concentration of 481% was measured for waste loads containing starch, corresponding to a glucose concentration at the end of hydrolysis of 7.5 g·L−1. In the subsequent set fermentation in serum bottles, a H2 yield of 1.26 mmol H2 was obtained in the overhead space when Terrific Broth Medium with glucose and yeast extract (TBGY medium) was used. When hydrolyzed organic waste was used, even a H2 yield of 1.37 mmol could be achieved in the overhead space. In addition, a dedicated reactor system for the anaerobic fermentation of T. neapolitana to produce H2 was developed. The bioreactor developed here can ferment anaerobically with a very low loss of produced gas. Here, after 24 h, a hydrogen concentration of 83% could be measured in the overhead space. KW - biological hydrogen KW - organic waste KW - dark fermentation KW - hydrolysis KW - pretreatment Y1 - 2024 U6 - https://doi.org/10.3390/en17122938 SN - 1996-1073 N1 - Corresponding author: Nils Tippkötter VL - 17 IS - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Varriale, Ludovica A1 - Hengsbach, Jan-Niklas A1 - Guo, Tianyi A1 - Kuka, Katrin A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Sustainable production of lactic acid using a perennial ryegrass as feedstock—a comparative study of fermentation at the bench- and reactor-scale, and ensiling JF - Sustainability N2 - Perennial ryegrass (Lolium perenne) is an underutilized lignocellulosic biomass that has several benefits such as high availability, renewability, and biomass yield. The grass press-juice obtained from the mechanical pretreatment can be used for the bio-based production of chemicals. Lactic acid is a platform chemical that has attracted consideration due to its broad area of applications. For this reason, the more sustainable production of lactic acid is expected to increase. In this work, lactic acid was produced using complex medium at the bench- and reactor scale, and the results were compared to those obtained using an optimized press-juice medium. Bench-scale fermentations were carried out in a pH-control system and lactic acid production reached approximately 21.84 ± 0.95 g/L in complex medium, and 26.61 ± 1.2 g/L in press-juice medium. In the bioreactor, the production yield was 0.91 ± 0.07 g/g, corresponding to a 1.4-fold increase with respect to the complex medium with fructose. As a comparison to the traditional ensiling process, the ensiling of whole grass fractions of different varieties harvested in summer and autumn was performed. Ensiling showed variations in lactic acid yields, with a yield up to 15.2% dry mass for the late-harvested samples, surpassing typical silage yields of 6–10% dry mass. KW - lactobacillus KW - lactic acid KW - ensiling KW - fermentation KW - perennial ryegrass KW - renewable resources KW - bio-based economy Y1 - 2024 U6 - https://doi.org/10.3390/su16188054 SN - 2071-1050 N1 - This article belongs to the Section "Environmental Sustainability and Applications" VL - 16 IS - 18 PB - MDPI CY - Basel ER - TY - JOUR A1 - Unden, Gottfried A1 - Becker, S. A1 - Bongaerts, Johannes A1 - Holighaus, G. A1 - Schirawski, Jan A1 - Six, Simon T1 - O2-sensing and O2-dependent gene regulation in facultatively anaerobic bacteria JF - Archives of microbiology Y1 - 1995 SN - 1432-072X (E-Journal); 0003-9276 (Print); 0302-8933 (Print) VL - Vol. 164 IS - Iss. 2 SP - 81 EP - 90 ER - TY - JOUR A1 - Unden, Gottfried A1 - Becker, S. A1 - Bongaerts, Johannes A1 - Schirawski, Jan A1 - Six, Simon T1 - Oxygen regulated gene expression in facultatively anaerobic bacteria JF - Antonie van Leeuwenhoek Y1 - 1994 SN - 0003-6072 (Print) ; 1572-9699 (online) VL - Vol. 66 IS - Iss. 1-3 SP - 3 EP - 22 ER - TY - JOUR A1 - Ribitsch, Doris A1 - Karl, Wolfgang A1 - Birner-Gruenberger, R. A1 - Gruber, K. A1 - Eiteljoerg, I. A1 - Remler, Peter A1 - Wieland, S. A1 - Siegert, Petra A1 - Maurer, Karl-Heinz A1 - Schwab, H. T1 - C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli JF - Journal of biotechnology N2 - 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. Y1 - 2010 U6 - https://doi.org/10.1016/j.jbiotec.2010.09.947 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 150 IS - 3 SP - 408 EP - 416 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Krafft, Simone A1 - Kuka, Katrin A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Utilization of Lolium perenne varieties as a renewable substrate for single-cell proteins, lactate, and composite materials T2 - Chemie Ingenieur Technik N2 - Lolium perenne (perennial ryegrass) is aproductive and high-quality forage grass indigenous to Southern Europe, temperate Asia, and North Africa. Nowadays it is widespread and the dominant grass species on green areas in temperate climates. This abundant source of biomass is suitable for the development of bioeconomic processes because of its high cellulose and water-soluble carbohydrate content. In this work, novel breeds of the perennial ryegrass are being examined with regards to their quality parameters and biotechnological utilization options within the context of bioeconomy. Three processing operations are presented. In the first process, the perennial ryegrass is pretreated by pressing or hydrothermal extraction to derive glucosevia subsequent enzymatic hydrolysis of cellulose. A yield of up to 82 % glucose was achieved when using the hydrothermal ex-traction as pretreatment. In a second process, the ryegrass is used to produce lactic acid in high concentrations. The influence of the growth conditions and the cutting time on the carboxylic acid yield is investigated. A yield of lactic acid of above 150 g kg⁻¹ dry matter was achieved. The third process is to use Lolium perenne as a substrate in the fermentation of K. marxianus for the microbial production of single-cell proteins. The perennial ryegrass is screw-pressed and the press juice is used as medium. When supplementing the press juice with yeast media components, a biomass concentration of up to 16 g L⁻¹ could be achieved. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255306 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1303 EP - 1304 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Rothkranz, Berit A1 - Krafft, Simone A1 - Tippkötter, Nils T1 - Media optimization for sustainable fuel production: How to produce biohydrogen from renewable resources with Thermotoga neapolitana T2 - Chemie Ingenieur Technik N2 - Hydrogen is playing an increasingly important role in research and politics as an energy carrier of the future. Since hydrogen has commonly been produced from methane by steam reforming, the need for climate-friendly, alternative production routes is emerging. In addition to electrolysis, fermentative routes for the production of so-called biohydrogen are "green" alternatives. The application of microorganisms offers the advantage of sustainable production from renewable resources using easily manageable technologies. In this project, the hyperthermophilic, anaerobic microorganism Thermotoga neapolitana is used for the productio nof biohydrogen from renewable resources. The enzymatically hydrolyzed resources were used in fermentation leading to yield coefficients of 1.8 mole H₂ per mole glucose when using hydrolyzed straw and ryegrass supplemented with medium, respectively. These results are similar to the hydrogen yields when using Thermotoga basal medium with glucose (TBGY) as control group. In order to minimize the supplementation of the hydrolysate and thus increase the economic efficiency of the process, the essential media components were identified. The experiments revealed NaCl, KCl, and glucose as essential components for cell growth as well as biohydrogen production. When excluding NaCl, a decrease of 96% in hydrogen production occured. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255305 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1298 EP - 1299 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Varriale, Ludovica A1 - Kuka, Katrin A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Use of a green biomass in a biorefinery platform T2 - Chemie Ingenieur Technik N2 - The emerging environmental issues due to the use of fossil resources are encouraging the exploration of new renewable resources. Biomasses are attracting more interest due to the low environmental impacts, low costs, and high availability on earth. In this scenario, green biorefineries are a promising platform in which green biomasses are used as feedstock. Grasses are mainly composed of cellulose and hemicellulose, and lignin is available in a small amount. In this work, a perennial ryegrass was used as feedstock to develop a green bio-refinery platform. Firstly, the grass was mechanically pretreated, thus obtaining a press juice and a press cake fraction. The press juice has high nutritional values and can be employed as part of fermentation media. The press cake can be employed as a substrate either in enzymatic hydrolysis or in solid-state fermentation. The overall aim of this work was to demonstrate different applications of both the liquid and the solid fractions. For this purpose, the filamentous fungus A. niger and the yeast Y. lipolythica were selected for their ability to produce citric acid. Finally, the possibility was assessed to use the press juice as part of fermentation media to cultivate S. cerevisiae and lactic acid bacteria for ethanol and lactic acid fermentation. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255095 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1299 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Ross-Jones, J. A1 - Teumer, T. A1 - Capitain, C. A1 - Tippkötter, Nils A1 - Krause, M. J. A1 - Methner, F.-J. A1 - Rädle, M. T1 - Analytical methods for in-line characterization of beer haze T2 - Trends in Brewing N2 - In most beers, producers strive to minimize haze to maximize visual appeal. To detect the formation of particulates, a measurement system for sub-micron particles is required. Beer haze is naturally occurring, composed of protein or polyphenol particles; in their early stage of growth their size is smaller than 2 µm. Microscopy analysis is time and resource intensive; alternatively, backscattering is an inexpensive option for detecting particle sizes of interest. Y1 - 2018 N1 - Trends in Brewing, April 8 –12, 2018, Ghent, Belgium ER -