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 - 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 - 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, Ruth A1 - Gruber, Karl A1 - Eiteljoerg, Inge A1 - Remler, Peter A1 - Wieland, Susanne A1 - Siegert, Petra A1 - Maurer, Karl-Heinz A1 - Schwab, Helmut 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 - JOUR A1 - Adels, Klaudia A1 - Thönnessen, Vera A1 - Monakhova, Yulia T1 - Complementary instrumental techniques applied to pain relieving tablets in an undergraduate laboratory experiment JF - Journal of Chemical Education N2 - Several unconnected laboratory experiments are usually offered for students in instrumental analysis lab. To give the students a more rational overview of the most common instrumental techniques, a new laboratory experiment was developed. Marketed pain relief drugs, familiar consumer products with one to three active components, namely, acetaminophen (paracetamol), acetylsalicylic acid (ASA), and caffeine, were selected. Common analytical methods were compared regarding the performance of qualitative and quantitative analysis of unknown tablets: UV–visible (UV–vis), infrared (IR), and nuclear magnetic resonance (NMR) spectroscopies, as well as high-performance liquid chromatography (HPLC). The students successfully uncovered the composition of formulations, which were divided into three difficulty categories. Students were shown that in addition to simple mixtures handled in theoretical classes, the composition of complex drug products can also be uncovered. By comparing the performance of different techniques, students deepen their understanding and compare the efficiency of analytical methods in the context of complex mixtures. The laboratory experiment can be adjusted for graduate level by including extra tasks such as method optimization, validation, and 2D spectroscopic techniques. KW - Instrumental analysis KW - Spectroscopy KW - Liquid chromatography KW - Qualitative and quantitative determination KW - Drugs Y1 - 2024 U6 - https://doi.org/10.1021/acs.jchemed.4c00681 SN - 0021-9584 (Print) SN - 1938-1328 (Online) PB - ACS ER - TY - JOUR A1 - Raue, Markus A1 - Wambach, M. A1 - Glöggler, Stefan A1 - Grefen, Dana A1 - Kaufmann, R. A1 - Abetz, C. A1 - Georgopanos, Prokopios A1 - Handge, U. A. A1 - Mang, Thomas A1 - Blümich, Bernhard A1 - Abetz, V. T1 - Investigation of historical hard rubber ornaments of Charles Goodyear JF - Macromolecular chemistry and physics Y1 - 2014 SN - 1022-1352 VL - Vol. 215 IS - No. 3 SP - 245 EP - 254 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 - Biselli, Manfred A1 - Schmidt, Sebastian A1 - Büchs, Jochen A1 - Born, Christoph T1 - A new correlation for the wall-to-fluid mass transfer in liquid-sol fluidized beds / Schmidt, S. ; Büchs, J. ; Born, C. ; Biselli, M. JF - Chemical Engineering Science. 54 (1999), H. 6 Y1 - 1999 SN - 0009-2509 SP - 829 EP - 839 ER - TY - JOUR A1 - Biselli, Manfred A1 - Born, Christoph A1 - Thömmes, J. A1 - Wandrey, C. T1 - An approach to integrated antibody production: Coupling of fluidized bed cultivation and fluidized bed adsorption / Born, C. ; Thömmes, J. ; Biselli, M. ; Wandrey, C. ; Kula, M.-R. JF - Bioprocess Engineering. 15 (1996), H. 1 Y1 - 1996 SN - 1615-7591 SP - 21 EP - 29 ER - TY - JOUR A1 - Biselli, Manfred A1 - Born, Christoph A1 - Wandrey, C. T1 - Oxygen transfer from the gasphase to the immobilized cells in membrane aerated fluidized beds / Born, C. ; Biselli, M. ; Wandrey, C. JF - Animal cell technology : basic & applied aspects : proceedings of the Eighth Annual Meeting of the Japanese Association for Animal Cell Technology, Iizuka, Fukuoka, Japan, November 6-10, 1995 / edited by K. Funatsu, Y. Shirai, and T. Matsushita Y1 - 1995 SN - 0-7923-4486-3 N1 - Japanese Association for Animal Cell Technology. ; Meeting ; <8 ; 1995 : ; Iizuka-shi, Japan> SP - 83 EP - 87 PB - Kluwer Acad. Press CY - Boston ER - TY - JOUR A1 - Biselli, Manfred A1 - Thömmes, J. A1 - Born, Christoph A1 - Wandrey, C. T1 - Purification of monoclonal antibodies by fluidized bed adsorption / Thömmes, J. ; Born, C. Biselli, M. ; Wandrey, C. ; Kula, M.-R. JF - Animal cell technology : developments towards the 21st century / edited by E. C. Beuvery Y1 - 1995 SN - 0-7923-3736-0 N1 - Meeting "Animal Cell Technology, Developments towards the 21st Century" ; <1994.09.12-16 : ; Veldhoven> SP - 515 EP - 519 PB - Kluwer Acad. Press CY - Dordrecht ER - TY - JOUR A1 - Biselli, Manfred A1 - Born, Christoph A1 - Wandrey, C. T1 - Production of monoclonal antibodies in a pilot scale fluidized bed bioreactor / Born, C.; Biselli, M.; Wandrey, C. JF - Animal cell technology : developments towards the 21st century / edited by E. C. Beuvery Y1 - 1995 SN - 0-7923-3736-0 N1 - Meeting "Animal Cell Technology, Developments towards the 21st Century" ; <1994.09.12-16 : ; Veldhoven> SP - 515 EP - 519 PB - Kluwer Acad. Press CY - Dordrecht ER - TY - CHAP A1 - Brandini, Frederico Pereira A1 - Baumann, Marcus T1 - The potential role of melted 'brown ice' as sources of chelators and ammonia to the surface waters of the Weddell Sea, Antarctica T2 - Proceedings of the NIPR Symposium on Polar Biology : 10 Y1 - 1997 SN - 0914-563X SP - 1 EP - 13 CY - Tokyo ER - TY - JOUR A1 - Baumann, Marcus A1 - Lancelot, Christiane A1 - Brandini, Frederico Pereira A1 - Sakshaug, Egil A1 - John, David Michael T1 - The taxonomic identity of the cosmopolitan prymnesiophyte Phaeocystis, a morphological and ecophysiological approach / Baumann, M.E.M. ; Lancelot, C. ; Brandini, F. ; Sakshaug, E. ; John M. JF - Journal of Marine Systems. 5 (1994), H. 1 Y1 - 1994 SN - 0924-7963 SP - 5 EP - 22 ER - TY - JOUR A1 - Baumann, Marcus A1 - Brandini, Frederico Pereira A1 - Staubes, Regina T1 - The influence of light and temperature on carbonspecific DMS release by cultures of Phaeocystis antarctica and three antarctic diatoms / Baumann, Marcus E.M. ; Brandini, Frederico ; Staubes, Regina JF - Marine Chemistry. 45 (1994), H. 1-2 Y1 - 1994 SN - 0304-4203 SP - 129 EP - 136 ER - TY - JOUR A1 - Bäcker, Matthias A1 - Raue, Markus A1 - Schusser, Sebastian A1 - Jeitner, C. A1 - Breuer, Lars A1 - Wagner, P. A1 - Poghossian, Arshak A1 - Förster, Arnold A1 - Mang, Thomas A1 - Schöning, Michael Josef T1 - Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films JF - Physica Status Solidi (a) N2 - Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off. Y1 - 2012 U6 - https://doi.org/10.1002/pssa.201100763 SN - 1862-6319 VL - 209 IS - 5 SP - 839 EP - 845 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Tix, Julian A1 - Gotthardt, Leon A1 - Bode, Joshua A1 - Karabacak, Burak A1 - Nordmann, Janne A1 - Hengsbach, Jan-Niklas A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Enhancement of succinic acid production by Actinobacillus succinogenes in an electro-bioreactor JF - Fermentation N2 - This work examines the electrochemically enhanced production of succinic acid using the bacterium Actinobacillus succinogenes. The principal objective is to enhance the metabolic potential of glucose and CO2 utilization via the C4 pathway in order to synthesize succinic acid. We report on the development of an electro-bioreactor system to increase succinic acid production in a power-2-X approach. The use of activated carbon fibers as electrode surfaces and contact areas allows A. succinogenes to self-initiate biofilm formation. The integration of an electrical potential into the system shifts the redox balance from NAD+ to NADH, increasing the efficiency of metabolic processes. Mediators such as neutral red facilitate electron transfer within the system and optimize the redox reactions that are crucial for increased succinic acid production. Furthermore, the role of carbon nanotubes (CNTs) in electron transfer was investigated. The electro-bioreactor system developed here was operated in batch mode for 48 h and showed improvements in succinic acid yield and concentration. In particular, a run with 100 µM neutral red and a voltage of −600 mV achieved a yield of 0.7 gsuccinate·gglucose−1. In the absence of neutral red, a higher yield of 0.72 gsuccinate·gglucose−1 was achieved, which represents an increase of 14% compared to the control. When a potential of −600 mV was used in conjunction with 500 µg∙L−1 CNTs, a 21% increase in succinate concentration was observed after 48 h. An increase of 33% was achieved in the same batch by increasing the stirring speed. These results underscore the potential of the electro-bioreactor system to markedly enhance succinic acid production. KW - A. succinogenes KW - power-to-X KW - electrofermentation KW - electro-bioreactor KW - succinate Y1 - 2024 U6 - https://doi.org/10.3390/fermentation10100504 SN - 2311-5637 N1 - Corresponding author: Nils Tippkötter N1 - This article belongs to the Special Issue "Advance in Microbial Electrochemical Technologies" VL - 10 IS - 10 PB - MDPI CY - Basel ER - TY - JOUR A1 - Heine, Andreas A1 - Herrmann, Gloria A1 - Selmer, Thorsten A1 - Terwesten, Felix A1 - Buckel, Wolfgang A1 - Reuter, Klaus T1 - High resolution crystal structure of clostridium propionicum β-Alanyl-CoA:Ammonia Lyase, a new member of the "Hot Dog Fold" protein superfamily JF - Proteins N2 - Clostridium propionicum is the only organism known to ferment β-alanine, a constituent of coenzyme A (CoA) and the phosphopantetheinyl prosthetic group of holo-acyl carrier protein. The first step in the fermentation is a CoA-transfer to β-alanine. Subsequently, the resulting β-alanyl-CoA is deaminated by the enzyme β-alanyl-CoA:ammonia lyase (Acl) to reversibly form ammonia and acrylyl-CoA. We have determined the crystal structure of Acl in its apo-form at a resolution of 0.97 Å as well as in complex with CoA at a resolution of 1.59 Å. The structures reveal that the enyzme belongs to a superfamily of proteins exhibiting a so called “hot dog fold” which is characterized by a five-stranded antiparallel β-sheet with a long α-helix packed against it. The functional unit of all “hot dog fold” proteins is a homodimer containing two equivalent substrate binding sites which are established by the dimer interface. In the case of Acl, three functional dimers combine to a homohexamer strongly resembling the homohexamer formed by YciA-like acyl-CoA thioesterases. Here, we propose an enzymatic mechanism based on the crystal structure of the Acl·CoA complex and molecular docking. Proteins 2014; 82:2041–2053. © 2014 Wiley Periodicals, Inc. Y1 - 2014 U6 - https://doi.org/10.1002/prot.24557 SN - 1097-0134 (E-Journal); 0887-3585 (Print) VL - 82 IS - 9 SP - 2041 EP - 2053 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Gerigk, M. A1 - Bujnicki, Robert A1 - Ganpo-Nkwenkwa, E. A1 - Bongaerts, Johannes A1 - Sprenger, Georg A. A1 - Takors, Ralf T1 - Process control for enhanced L-phenylalanine production using different recombinant Escherichia coli strains JF - Biotechnology and bioengineering Y1 - 2002 SN - 1097-0290 (E-Journal); 0006-3592 (Print) VL - Vol. 80 IS - Iss. 7 SP - 746 EP - 754 ER - TY - JOUR A1 - Teumer, Tobias A1 - Capitain, Charlotte A1 - Ross-Jones, Jesse A1 - Tippkötter, Nils A1 - Rädle, Matthias A1 - Methner, Frank-Jürgen T1 - In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor JF - BrewingScience N2 - In the present work an optical sensor in combination with a spectrally resolved detection device for in-line particle-size-monitoring for quality control in beer production is presented. The principle relies on the size and wavelength dependent backscatter of growing particles in fluids. Measured interference structures of backscattered light are compared with calculated theoretical values, based on Mie-Theory, and fitted with a linear least square method to obtain particle size distributions. For this purpose, a broadband light source in combination with a process-CCD-spectrometer (charge ? coupled device spectrometer) and process adapted fiber optics are used. The goal is the development of an easy and flexible measurement device for in-line-monitoring of particle size. The presented device can be directly installed in product fill tubes or vessels, follows CIP- (cleaning in place) and removes the need of sample taking. A proof of concept and preliminary results, measuring protein precipitation, are presented. Y1 - 2018 SN - 1613-2041 VL - 71 IS - 5/6 SP - 49 EP - 55 PB - Fachverlag Hans Carl CY - Nürnberg ER - TY - JOUR A1 - Wagner, Torsten A1 - Molina, R. A1 - Biselli, Manfred A1 - Canzoneri, Michelangelo A1 - Schnitzler, Thomas A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef T1 - A light-addressable potentiometric sensor system for fast, simultaneous and spatial detection of the metabolic activity of biological cells JF - Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.) Y1 - 2007 SN - 1-4244-0841-5 N1 - Eurosensors 21, 2007, Lyon ; International Conference on Solid-State Sensors, Actuators and Microsystems 14, 2007, Lyon SP - 1107 EP - 1110 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Wagner, Torsten A1 - Molina, Roberto A1 - Yoshinobu, Tatsuo A1 - Kloock, Joachim P. A1 - Biselli, Manfred A1 - Canzoneri, Michelangelo A1 - Schnitzler, Thomas A1 - Schöning, Michael Josef T1 - Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications JF - Electrochimica Acta. 53 (2007), H. 2 Y1 - 2007 SN - 0013-4686 SP - 305 EP - 311 ER - TY - GEN A1 - Möhring, S. A1 - Wulfhorst, Helene A1 - Capitain, Charlotte 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 - GEN A1 - Ross-Jones, Jesse A1 - Teumer, Tobias A1 - Capitain, Charlotte A1 - Tippkötter, Nils A1 - Krause, Mathias J. A1 - Methner, Frank-Jürgen A1 - Rädle, Matthias 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 -