TY  - JOUR
A1  - Roth, Jasmine
A1  - Tippkötter, Nils
T1  - Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium
JF  - Cellulose Chemistry and Technology
N2  - Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹.
Y1  - 2016
VL  - 50
IS  - 3-4
SP  - 405
EP  - 410
PB  - Editura Academiei Romane
CY  - Bukarest
ER  - 
TY  - JOUR
A1  - Schwab, Lukas
A1  - Hojdis, Nils
A1  - Lacayo, Jorge
A1  - Wilhelm, Manfred
T1  - Fourier-Transform Rheology of Unvulcanized, Carbon Black Filled Styrene Butadiene Rubber
JF  - Macromolecular Materials and Engineering
N2  - Rubber materials filled with reinforcing fillers display nonlinear rheological behavior at small strain amplitudes below γ0 < 0.1. Nevertheless, rheological data are analyzed mostly in terms of linear parameters, such as shear moduli (G′, G″), which loose their physical meaning in the nonlinear regime. In this work styrene butadiene rubber filled with carbon black (CB) under large amplitude oscillatory shear (LAOS) is analyzed in terms of the nonlinear parameter I3/1. Three different CB grades are used and the filler load is varied between 0 and 70 phr. It is found that I3/1(φ) is most sensitive to changes of the total accessible filler surface area at low strain amplitudes (γ0 = 0.32). The addition of up to 70 phr CB leads to an increase of I3/1(φ) by a factor of more than ten. The influence of the measurement temperature on I3/1 is pronounced for CB levels above the percolation threshold.
Y1  - 2016
U6  - https://doi.org/10.1002/mame.201500356
SN  - 1439-2054
VL  - 301
IS  - 4
SP  - 457
EP  - 468
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  - Dallas, Shannon
A1  - Salphati, Laurent
A1  - Gomez-Zepeda, David
A1  - Wanek, Thomas
A1  - Chen, Liangfu
A1  - Chu, Xiaoyan
A1  - Kunta, Jeevan
A1  - Mezler, Mario
A1  - Menet, Marie-Claude
A1  - Chasseigneaux, Stephanie
A1  - Declèves, Xavier
A1  - Langer, Oliver
A1  - Pierre, Esaie
A1  - DiLoreto, Karen
A1  - Hoft, Carolin
A1  - Laplanche, Loic
A1  - Pang, Jodie
A1  - Pereira, Tony
A1  - Andonian, Clara
A1  - Simic, Damir
A1  - Rode, Anja
A1  - Yabut, Jocelyn
A1  - Zhang, Xiaolin
A1  - Scheer, Nico
T1  - Generation and Characterization of a Breast Cancer Resistance Protein Humanized Mouse Model
JF  - Molecular Pharmacology
N2  - Breast cancer resistance protein (BCRP) is expressed in various tissues, such as the gut, liver, kidney and blood brain barrier (BBB), where it mediates the unidirectional transport of substrates to the apical/luminal side of polarized cells. Thereby BCRP acts as an efflux pump, mediating the elimination or restricting the entry of endogenous compounds or xenobiotics into tissues and it plays important roles in drug disposition, efficacy and safety. Bcrp knockout mice (Bcrp−/−) have been used widely to study the role of this transporter in limiting intestinal absorption and brain penetration of substrate compounds. Here we describe the first generation and characterization of a mouse line humanized for BCRP (hBCRP), in which the mouse coding sequence from the start to stop codon was replaced with the corresponding human genomic region, such that the human transporter is expressed under control of the murine Bcrp promoter. We demonstrate robust human and loss of mouse BCRP/Bcrp mRNA and protein expression in the hBCRP mice and the absence of major compensatory changes in the expression of other genes involved in drug metabolism and disposition. Pharmacokinetic and brain distribution studies with several BCRP probe substrates confirmed the functional activity of the human transporter in these mice. Furthermore, we provide practical examples for the use of hBCRP mice to study drug-drug interactions (DDIs). The hBCRP mouse is a promising model to study the in vivo role of human BCRP in limiting absorption and BBB penetration of substrate compounds and to investigate clinically relevant DDIs involving BCRP.
Y1  - 2016
U6  - https://doi.org/10.1124/mol.115.102079
SN  - 1521-0111
VL  - 89
IS  - 5
SP  - 492
EP  - 504
PB  - ASPET
CY  - Bethesda, Md.
ER  - 
TY  - CHAP
A1  - Tippkötter, Nils
ED  - Kaltschmidt, Martin
T1  - Grundlagen der bio-chemischen Umwandlung
T2  - Energie aus Biomasse : Grundlagen, Techniken und Verfahren
Y1  - 2016
SN  - 978-3-662-47437-2 (Print)
SN  - 978-3-662-47438-9 (Online)
U6  - https://doi.org/10.1007/978-3-662-47438-9
SP  - 1447
EP  - 1500
PB  - Springer Vieweg
CY  - Berlin ; Heidelberg
ET  - 3., aktualisierte, erweiterte Auflage
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Raue, Markus
A1  - Strobel, M.
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, R.
A1  - Wagner, Torsten
T1  - Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems
JF  - Physica status solidi (a)
N2  - Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201533056
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1520
EP  - 1525
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Scheer, Nico
A1  - Chu, Xiaoyan
A1  - Salphati, Laurent
A1  - Zamek-Gliszczynski, Maciej J.
ED  - Nicholls, Glynis
T1  - Knockout and humanized animal models to study membrane transporters in drug development
T2  - Drug Transporters: Volume 1: Role and Importance in ADME and Drug Development
Y1  - 2016
SN  - 978-1-78262-379-3
U6  - https://doi.org/10.1039/9781782623793-00298
SP  - 298
EP  - 332
PB  - Royal Society of Chemistry
CY  - Cambridge
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  - Harish, Ajay B.
A1  - Wriggers, Peter
A1  - Jungk, Juliane
A1  - Hojdis, Nils
A1  - Recker, Carla
T1  - Mesoscale Constitutive Modeling of Non-Crystallizing Filled Elastomers
JF  - Computational Mechanics
N2  - Elastomers are exceptional materials owing to their ability to undergo large deformations before failure. However, due to their very low stiffness, they are not always suitable for industrial applications. Addition of filler particles provides reinforcing effects and thus enhances the material properties that render them more versatile for applications like tyres etc. However, deformation behavior of filled polymers is accompanied by several nonlinear effects like Mullins and Payne effect. To this day, the physical and chemical changes resulting in such nonlinear effect remain an active area of research. In this work, we develop a heterogeneous (or multiphase) constitutive model at the mesoscale explicitly considering filler particle aggregates, elastomeric matrix and their mechanical interaction through an approximate interface layer. The developed constitutive model is used to demonstrate cluster breakage, also, as one of the possible sources for Mullins effect observed in non-crystallizing filled elastomers.
Y1  - 2016
U6  - https://doi.org/10.1007/s00466-015-1251-1
SN  - 1432-0924
VL  - 57
SP  - 653
EP  - 677
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Engel, M.
A1  - Thieringer, J.
A1  - Tippkötter, Nils
T1  - Microbial electrosynthesis for sustainable biobutanol production
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 77
EP  - 78
PB  - DECHEMA
CY  - Frankfurt am Main
ER  -