@article{FalkenbergBottBongaertsetal.2022, author = {Falkenberg, Fabian and Bott, Michael and Bongaerts, Johannes and Siegert, Petra}, title = {Phylogenetic survey of the subtilase family and a data-mining-based search for new subtilisins from Bacillaceae}, series = {Frontiers in Microbiology}, volume = {2022}, journal = {Frontiers in Microbiology}, number = {13}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-302X}, doi = {10.3389/fmicb.2022.1017978}, pages = {Artikel 13:1017978}, year = {2022}, abstract = {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.}, language = {en} } @article{EveraersKarimiVarzanehFlecketal.2020, author = {Everaers, Ralf and Karimi-Varzaneh, Hossein Ali and Fleck, Franz and Hojdis, Nils and Svaneborg, Carsten}, title = {Kremer-Grest Models for Commodity Polymer Melts: Linking Theory, Experiment, and Simulation at the Kuhn Scale}, series = {Macromolecules}, volume = {53}, journal = {Macromolecules}, number = {6}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-5835}, doi = {10.1021/acs.macromol.9b02428}, pages = {1901 -- 1916}, year = {2020}, abstract = {The Kremer-Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.}, language = {en} } @inproceedings{EngelThieringerTippkoetter2016, author = {Engel, Mareike and Thieringer, Julia and Tippk{\"o}tter, Nils}, title = {Linking bioprocess engineering and electrochemistry for sustainable biofuel production}, series = {Young Researchers Symposium, YRS 2016. Proceedings}, booktitle = {Young Researchers Symposium, YRS 2016. Proceedings}, publisher = {Fraunhofer Verlag}, address = {Karlsruhe}, pages = {49 -- 53}, year = {2016}, abstract = {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.}, language = {en} } @article{EngelHoltmannUlberetal.2018, author = {Engel, Mareike and Holtmann, Dirk and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Increased Biobutanol Production by Mediator-Less Electro-Fermentation}, series = {Biotechnology Journal}, volume = {14}, journal = {Biotechnology Journal}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1860-7314}, doi = {10.1002/biot.201800514}, year = {2018}, abstract = {A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at -600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6\% compared to 23.3\% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry.}, language = {en} } @article{EngelGemuendeHoltmannetal.2019, author = {Engel, Mareike and Gem{\"u}nde, Andre and Holtmann, Dirk and M{\"u}ller-Renno, Christine and Ziegler, Christiane and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Clostridium acetobutylicum's connecting world: cell appendage formation in bioelectrochemical systems}, series = {ChemElectroChem}, volume = {7}, journal = {ChemElectroChem}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {2196-0216}, doi = {10.1002/celc.201901656}, pages = {414 -- 420}, year = {2019}, abstract = {Bacterial cell appendix formation supports cell-cell interaction, cell adhesion and cell movement. Additionally, in bioelectrochemical systems (BES), cell appendages have been shown to participate in extracellular electron transfer. In this work, the cell appendix formation of Clostridium acetobutylicum in biofilms of a BES are imaged and compared with conventional biofilms. Under all observed conditions, the cells possess filamentous appendages with a higher number and density in the BES. Differences in the amount of extracellular polymeric substance in the biofilms of the electrodes lead to the conclusion that the cathode can be used as electron donor and the anode as electron acceptor by C. acetobutylicum. When using conductive atomic force microscopy, a current response of about 15 nA is found for the cell appendages from the BES. This is the first report of conductivity for clostridial cell appendices and represents the basis for further studies on their role for biofilm formation and electron transfer.}, language = {en} } @article{EngelBayerHoltmannetal.2019, author = {Engel, Mareike and Bayer, Hendrik and Holtmann, Dirk and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Flavin secretion of Clostridium acetobutylicum in a bioelectrochemical system - Is an iron limitation involved?}, series = {Bioelectrochemistry}, journal = {Bioelectrochemistry}, number = {In Press, Accepted Manuscript}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1567-5394}, doi = {10.1016/j.bioelechem.2019.05.014}, year = {2019}, language = {en} } @misc{EngelTippkoetter2016, author = {Engel, M. and Tippk{\"o}tter, Nils}, title = {Einfluss eines Phenazin-Mediators und elektrischen Potenzials auf die Aceton-Butanol-Ethanol-Fermentation}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201650105}, pages = {1254}, year = {2016}, abstract = {In den letzten Jahren haben nachhaltige, biotechnologische Prozesse zunehmend an Bedeutung gewonnen. Die Aceton-Butanol-Ethanol-Fermentation (ABE-Fermentation) mit dem anaeroben Bakterium Clostridium acetobutylicum zur Gewinnung von Biobutanol k{\"o}nnte in diesem Zusammenhang eine M{\"o}glichkeit der nachhaltigen Kraftstoffproduktion darstellen. In dieser Arbeit wird der Einfluss zus{\"a}tzlich verf{\"u}gbarer Elektronen durch den Einsatz des Phenazin-Farbstoffs Neutralrot als Redoxmediator sowie das Anlegen eines elektrischen Potenzials w{\"a}hrend der ABE-Fermentation untersucht. Es wird gezeigt, dass das Neutralrot keinen Einfluss auf die Leerlaufspannung von ca. 500 mV vs. Ag/AgCl w{\"a}hrend der Fermentation hat. Der Mediator bewirkt allerdings eine fr{\"u}here Butanolbildung sowie h{\"o}here Butanolkonzentrationen. Wird zudem die Mediatorkonzentration von 125 mM auf 250 mM angehoben, wird dabei auch die maximale Butanolkonzentration um 36 \% ± 1,8 \% innerhalb von28 Stunden gesteigert.}, language = {de} } @inproceedings{EngelThieringerTippkoetter2016, author = {Engel, M. and Thieringer, J. and Tippk{\"o}tter, Nils}, title = {Microbial electrosynthesis for sustainable biobutanol production}, series = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany}, booktitle = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany}, publisher = {DECHEMA}, address = {Frankfurt am Main}, pages = {77 -- 78}, year = {2016}, language = {en} } @misc{EngelBayerUlberetal.2018, author = {Engel, M. and Bayer, H. and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Kommt es in Elektrofermentationen mit Clostridium acetobutylicum zu einer Eisenlimitierung?}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201855047}, pages = {1154}, year = {2018}, abstract = {Das strikt anaerobe Bakterium Clostridium acetobutylicum bildet die L{\"o}semittel Aceton, Butanol und Ethanol (ABE-Fermentation). Im Fall einer Eisenlimitierung kommt es zus{\"a}tzlich zu einer Riboflavinsekretion (RF), was durch die gelbe F{\"a}rbung des Kultur{\"u}berstands erkennbar ist. In dieser Arbeit wurde beobachtet, dass w{\"a}hrend Elektrofermentationen mit C. acetobutylicum bei -600 mV eine gelbe F{\"a}rbung auftritt. Es wurde deshalb untersucht, ob eine Eisenlimitierung im bio-elektrochemischen System (BES) vorliegt. Hierzu wurden die Flavinspezien bei Kultivierungen in Medien mit einer Eisenlimitierung bzw. mit ausreichend Eisen in Serumflaschen sowie im BES mit und ohne angelegtem Potenzial verglichen. In den Serumflaschenversuchen wurden RF und Flavinadenindinukleotid (FAD)-Konzentrationen von ‡ 20 mg L⁻¹ sowie Flavinmononukleotid (FMN)-Konzentrationen von ca. 5 mg L⁻¹ detektiert. Bei ausreichender Eisenverf{\"u}gbarkeit hingegen wurden in den Serumflaschen fast keine Flavine sekretiert. Im BES bei -600 mV hingegen wurde auch in diesen Kultur{\"u}berst{\"a}nden FMN und FAD (1-5 mg L⁻¹ ),jedoch kein RF gemessen. Diese Ergebnisse zeigen, dass die Flavinbildung im BES mit angelegtem Potenzial nicht mit der Flavinbildung unter Eisenlimitierung in Serumflaschen korreliert. Andere Faktoren f{\"u}r eine m{\"o}gliche Flavinbildung werden aktuell n{\"a}her betrachtet.}, language = {de} } @article{ElbersZangBuck1990, author = {Elbers, Gereon and Zang, Thorsten and Buck, Manfred}, title = {Ruß-Immissionsmessungen im Einflußbereich des Kraftfahrzeugverkehrs}, series = {Staub, Reinhaltung der Luft : air quality control. 50 (1990)}, journal = {Staub, Reinhaltung der Luft : air quality control. 50 (1990)}, isbn = {0039-0771}, pages = {93}, year = {1990}, language = {de} } @article{ElbersThomzik1990, author = {Elbers, Gereon and Thomzik, Manfred}, title = {Das Entstehen geruchsintensiver schwefelhaltiger organischer Verbindungen in Lackierereien und M{\"o}glichkeiten zu deren Vermeidung}, series = {Aus der T{\"a}tigkeit der LIS / Landesanstalt f{\"u}r Immissionsschutz des Landes Nordrhein-Westfalen. 1989 (1990)}, journal = {Aus der T{\"a}tigkeit der LIS / Landesanstalt f{\"u}r Immissionsschutz des Landes Nordrhein-Westfalen. 1989 (1990)}, isbn = {0931-5497}, pages = {35}, year = {1990}, language = {de} } @article{ElbersRichter1994, author = {Elbers, Gereon and Richter, J.}, title = {Messung kraftfahrzeugbedingter Rußimmissionen}, series = {Staub, Reinhaltung der Luft : air quality control. 54 (1994)}, journal = {Staub, Reinhaltung der Luft : air quality control. 54 (1994)}, isbn = {0039-0771}, pages = {19}, year = {1994}, language = {de} } @article{ElbersRemmeLehmann1986, author = {Elbers, Gereon and Remme, S. and Lehmann, G.}, title = {EPR of Cr3+ in Tris(acetylacetonato)gallium(III) Single Crystals}, series = {Inorganic Chemistry. 25 (1986)}, journal = {Inorganic Chemistry. 25 (1986)}, isbn = {0020-1669}, pages = {896 -- 897}, year = {1986}, language = {en} } @article{ElbersRemmeLehmann1987, author = {Elbers, Gereon and Remme, S. and Lehmann, G.}, title = {EPR and Optical Absorption of Cr3+ in CsCl and CsBr}, series = {Physica Status Solidi (B). 142 (1987), H. 2}, journal = {Physica Status Solidi (B). 142 (1987), H. 2}, isbn = {0031-8957}, pages = {367 -- 377}, year = {1987}, language = {en} } @article{ElbersPfefferFrieseletal.1995, author = {Elbers, Gereon and Pfeffer, Hans-Ulrich and Friesel, J{\"u}rgen and Beier, Reinhold}, title = {Air Pollution Monitoring in Street Canyons / Hans-Ulrich Pfeffer, J{\"u}rgen Friesel, Gereon Elbers, Reinhold Beier,}, series = {Transport and air pollution : proceedings ; 3rd international symposium, Palais des Papes, Avignon, France, 6 - 10 June 1994 = Transports et pollution de l'air / [Third International Symposium on Transport and Air Pollution]. Ed. by Robert Joumard. Organizer: French National Institute for Transport and Safety Research}, journal = {Transport and air pollution : proceedings ; 3rd international symposium, Palais des Papes, Avignon, France, 6 - 10 June 1994 = Transports et pollution de l'air / [Third International Symposium on Transport and Air Pollution]. Ed. by Robert Joumard. Organizer: French National Institute for Transport and Safety Research}, publisher = {Elsevier}, address = {Amsterdam}, pages = {IX, 337 S : graph. Darst.}, year = {1995}, language = {en} } @article{ElbersPfefferFrieseletal.1993, author = {Elbers, Gereon and Pfeffer, H.-U. and Friesel, J. and Beier, R.}, title = {Pilotuntersuchungen gem{\"a}ß dem Verordnungsentwurf nach \S 40, Abs. 2 des Bundesimmissionsschutzgesetzes / H.-U. Pfeffer, J. Friesel, G. Elbers, R. Beier, K. Ellermann}, series = {Drei Jahrzehnte Luftqualit{\"a}ts{\"u}berwachung : Vortr{\"a}ge und Berichte zum Kolloquium "Drei Jahrzehnte Luftqualit{\"a}ts{\"u}berwachung - Bilanz und Perspektiven" am 11. November 1993 in Essen / [Hrsg.: Landesanstalt f{\"u}r Immissionsschutz Nordrhein-Westfalen. Red. Bearb.: Robert Niesenhaus]}, journal = {Drei Jahrzehnte Luftqualit{\"a}ts{\"u}berwachung : Vortr{\"a}ge und Berichte zum Kolloquium "Drei Jahrzehnte Luftqualit{\"a}ts{\"u}berwachung - Bilanz und Perspektiven" am 11. November 1993 in Essen / [Hrsg.: Landesanstalt f{\"u}r Immissionsschutz Nordrhein-Westfalen. Red. Bearb.: Robert Niesenhaus]}, address = {Essen}, pages = {117}, year = {1993}, language = {de} } @article{ElbersNierenHoffmannetal.2008, author = {Elbers, Gereon and Nieren, Monika and Hoffmann, Katharina and G{\"a}b, Martina}, title = {Schnellerfassung der Wirkung von Luftschadstoffen auf Pflanzen mit der Nahinfrarotspektroskopie (NIRS). Untersuchung Ammoniak exponierter Gr{\"a}ser und Kr{\"a}uter / Nieren, Monika ; Hoffmann, Katharina ; G{\"a}b, Martina ; Ooyen, Sven van ; K{\"o}llner, Barbara ; Elbe}, series = {Immissionsschutz. 13 (2008), H. 2}, journal = {Immissionsschutz. 13 (2008), H. 2}, isbn = {1430-9262}, pages = {82 -- 90}, year = {2008}, language = {de} } @article{ElbersMuratyan1991, author = {Elbers, Gereon and Muratyan, Simone}, title = {Problematik verkehrsbezogener Außenluftmessungen von Partikeln (Dieselruß)}, series = {+ Krebserzeugende Stoffe in der Umwelt : Herkunft, Messung, Risiko, Minimierung ; Kolloquium Mannheim, 23. bis 25. April 1991 / Kommission Reinhaltung der Luft im VDI und DIN}, journal = {+ Krebserzeugende Stoffe in der Umwelt : Herkunft, Messung, Risiko, Minimierung ; Kolloquium Mannheim, 23. bis 25. April 1991 / Kommission Reinhaltung der Luft im VDI und DIN}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {3-18-090888-2}, pages = {143}, year = {1991}, language = {de} } @article{ElbersLehmann1985, author = {Elbers, Gereon and Lehmann, G.}, title = {Electron paramagnetic resonance of Vanadyl ion impurities in crystalline solids: A comment}, series = {Journal of Physics and Chemistry of Solids. 46 (1985), H. 6}, journal = {Journal of Physics and Chemistry of Solids. 46 (1985), H. 6}, isbn = {0022-3697}, pages = {761}, year = {1985}, language = {en} } @article{ElbersLehmann1985, author = {Elbers, Gereon and Lehmann, G.}, title = {Electron Paramagnetic Resonance and Optical Absorption Spectra of VO2+ in CsCl Single Crystals}, series = {Zeitschrift f{\"u}r Naturforschung / Section A, a journal of physical sciences. 40 (1985)}, journal = {Zeitschrift f{\"u}r Naturforschung / Section A, a journal of physical sciences. 40 (1985)}, isbn = {0932-0784}, pages = {511}, year = {1985}, language = {en} }