TY  - JOUR
A1  - Liu, Z.
A1  - Schaap, K. S.
A1  - Ballemans, L.
A1  - de Blois, E.
A1  - Rohde, M.
A1  - Paulßen, Elisabeth
T1  - Measurement of reaction kinetics of [177Lu]Lu-DOTA-TATE using a microfluidic system
JF  - Dalton Transactions
Y1  - 2017
U6  - http://dx.doi.org/10.1039/C7DT01830D
SN  - 1477-9234
VL  - 46
IS  - 42
SP  - 14669
EP  - 14676
ER  - 
TY  - JOUR
A1  - Infantino, Angelo
A1  - Paulßen, Elisabeth
A1  - Mostacci, Domiziano
A1  - Schaffer, Paul
A1  - Trinczek, Michael
A1  - Hoehr, Cornelia
T1  - Assessment of the production of medical isotopes using the Monte Carlo code FLUKA: Simulations against experimental measurements
JF  - Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
N2  - The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, ¹⁸F, ¹³N, ⁹⁴Tc, ⁴⁴Sc, ⁶⁸Ga, ⁸⁶Y, ⁸⁹Zr, ⁵²Mn, ⁶¹Cu and ⁵⁵Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of ⁵⁵Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.nimb.2015.10.067
SN  - 1872-9584
VL  - 366
SP  - 117
EP  - 123
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hoehr, Cornelia
A1  - Paulßen, Elisabeth
A1  - Benard, Francois
A1  - Lee, Chris Jaeil
A1  - Hou, Xinchi
A1  - Badesso, Brian
A1  - Ferguson, Simon
A1  - Miao, Qing
A1  - Yang, Hua
A1  - Buckley, Ken
A1  - Hanemaayer, Victoire
A1  - Zeisler, Stefan
A1  - Ruth, Thomas
A1  - Celler, Anna
A1  - Schaffer, Paul
T1  - ⁴⁴ᶢSc production using a water target on a 13 MeV cyclotron
JF  - Nuclear medicine and biology
N2  - Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t₁⸝₂ = 3.97 h, Eavg,β⁺ = 1.47 MeV, branching ratio = 94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations.
Y1  - 2014
U6  - http://dx.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  - Paulßen, Elisabeth
A1  - Hoehr, Cornelia
A1  - Hou, Xinchi
A1  - Hanemaayer, Victoire
A1  - Zeisler, Stefan
A1  - Adam, Michael J.
A1  - Ruth, Thomas J.
A1  - Celler, Anna
A1  - Buckley, Ken
A1  - Benard, Francois
A1  - Schaffer, Paul
T1  - Production of Y-86 and other radiometals for research purposes using a solution target system
JF  - Nuclear medicine and biology
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.nucmedbio.2015.06.005
SN  - 1872-9614
VL  - 42
IS  - 11
SP  - 842
EP  - 849
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Lengkeek, Nigel A.
A1  - Le, Van So
A1  - Pellegrini, Paul A.
A1  - Greguric, Ivan
A1  - Weiner, Ron
T1  - The role of additives in moderating the influence of Fe(III) and Cu(II) on the radiochemical yield of [⁶⁸Ga(DOTATATE)]
JF  - Applied Radiation and Isotopes
N2  - [⁶⁸Ga(DOTATATE)] has demonstrated its clinical usefulness. Both Fe³⁺ and Cu²⁺, potential contaminants in Gallium-68 generator eluent, substantially reduce the radiochemical (RC) yield of [⁶⁸Ga(DOTATATE)] if the metal/ligand ratio of 1:1 is exceeded. A variety of compounds were examined for their potential ability to reduce this effect. Most had no effect on RC yield. However, addition of phosphate diminished the influence of Fe³⁺ by likely forming an insoluble iron salt. Addition of ascorbic acid reduced Cu²⁺ and Fe³⁺ to Cu⁺ and Fe²⁺ respectively, both of which have limited impact on RC yields. At low ligand amounts (5 nmol DOTATATE), the addition of 30 nmol phosphate (0.19 mM) increased the tolerance of Fe3⁺ from 4 nmol to 10 nmol (0.06 mM), while the addition of ascorbic acid allowed high RC yields (>95%) in the presence of 40 nmol Fe³⁺ (0.25 mM) and 100 nmol Cu²⁺ (0.63 mM). The effect of ascorbic acid was highly pH-dependant, and gave optimal results at pH 3.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.apradiso.2015.09.008
SN  - 1872-9800
VL  - 107
SP  - 13
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Le, Van So
A1  - Lengkeek, Nigel
A1  - Pellegrini, Paul
A1  - Jackson, Tim
A1  - Greguric, Ivan
A1  - Weiner, Ron
T1  - Influence of Metal Ions on the 68Ga-labeling of DOTATATE
JF  - Applied Radiation and Isotopes
Y1  - 2013
U6  - http://dx.doi.org/10.1016/j.apradiso.2013.08.010
SN  - 1872-9800
VL  - 82
SP  - 232
EP  - 238
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pellegrini, Paul A.
A1  - Howell, Nicholas R.
A1  - Shepherd, Rachael K.
A1  - Lengkeek, Nigel A.
A1  - Paulßen, Elisabeth
A1  - Katsifis, Andrew G.
A1  - Greguric, Ivan
T1  - Synthesis and Radiolabelling of DOTA-Linked Glutamine Analogues with 67,68Ga as Markers for Increased Glutamine Metabolism in Tumour Cells
JF  - Molecules
Y1  - 2013
U6  - http://dx.doi.org/10.3390/molecules18067160
SN  - 1420-3049
VL  - 18
IS  - 6
SP  - 7160
EP  - 7178
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Ngyugen, Hung Huy
A1  - Kahlcke, Nils
A1  - Deflon, Victor M.
A1  - Abram, Ulrich
T1  - Tricarbonyltechnetium(I) and -rhenium(I) complexes with N′-thiocarbamoylpicolylbenzamidines
JF  - Polyhedron
N2  - N,N-Dialkylamino(thiocarbonyl)-N′-picolylbenzamidines react with (NEt4)2[M(CO)3X3] (M = Re, X = Br; M = Tc, X = Cl) under formation of neutral [M(CO)3L] complexes in high yields. The monoanionic NNS ligands bind in a facial coordination mode and can readily be modified at the (CS)NR1R2 moiety. The complexes [99Tc(CO)3(LPyMor)] and [Re(CO)3(L)] (L = LPyMor, LPyEt) were characterized by X-ray diffraction. Reactions of [99mTc(CO)3(H2O)3]+ with the N′-thiocarbamoylpicolylbenzamidines give the corresponding 99mTc complexes. The ester group in HLPyCOOEt allows linkage between biomolecules and the metal core.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.poly.2012.04.008
SN  - 0277-5387
VL  - 40
IS  - 1
SP  - 153
EP  - 158
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - 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  - http://dx.doi.org/10.1002/ejic.201000522
SN  - 1099-0682
IS  - 29
SP  - 4622
EP  - 4630
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Kong, Shushu
A1  - Arciszewski, Pawel
A1  - Wielbalck, Swantje
A1  - Abram, Ulrich
T1  - Aryl and NHC Compounds of Technetium and Rhenium
JF  - Journal of the American Chemical Society
N2  - Air- and water-stable phenyl complexes with nitridotechnetium(V) cores can be prepared by straightforward procedures. [TcNPh2(PPh3)2] is formed by the reaction of [TcNCl2(PPh3)2] with PhLi. The analogous N-heterocyclic carbene (NHC) compound [TcNPh2(HLPh)2], where HLPh is 1,3,4-triphenyl-1,2,4-triazol-5-ylidene, is available from (NBu4)[TcNCl4] and HLPh or its methoxo-protected form. The latter compound allows the comparison of different Tc–C bonds within one compound. Surprisingly, the Tc chemistry with such NHCs does not resemble that of corresponding Re complexes, where CH activation and orthometalation dominate.
Y1  - 2012
U6  - http://dx.doi.org/10.1021/ja3033718
SN  - 1520-5126
VL  - 134
IS  - 22
SP  - 9118
EP  - 9121
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Alberto, Roger
A1  - Abram, Ulrich
T1  - Synthesis, Characterization, and Structures of R3EOTcO3 Complexes (E = C, Si, Ge, Sn, Pb) and Related Compounds
JF  - Inorganic Chemistry
N2  - AgTcO4 reacts with R3ECl compounds (E = C, Si, Ge, Sn, Pb; R = Me, iPr, tBu, Ph), tBu2SnCl2, or PhMgCl under formation of novel trioxotechnetium(VII) derivatives. The carbon and silicon derivatives readily undergo decomposition, which was proven by 99Tc NMR spectroscopy and the isolation of decomposition products such as [TcOCl3(THF)(OH2)]. Compounds [Ph3GeOTcO3], [(THF)Ph3SnOTcO3], [(O3TcO)SntBu2(OH)]2, and [(THF)4Mg(OTcO3)2] are more stable and were isolated in crystalline form and characterized by X-ray diffraction.
Y1  - 2010
U6  - http://dx.doi.org/10.1021/ic1001094
SN  - 1520-510X
VL  - 49
IS  - 7
SP  - 3525
EP  - 3530
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Braband, Henrik
A1  - Yegen, Eda
A1  - Paulßen, Elisabeth
A1  - Abram, Ulrich
T1  - [{ReN(PMe2Ph)3}{ReO3N}]2 – Structural Evidence for the Nitridotrioxorhenate(VII) Anion, [ReO3N]2−
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
Y1  - 2005
U6  - http://dx.doi.org/10.1002/zaac.200500240
SN  - 1521-3749
VL  - 631
IS  - 12
SP  - 2408
EP  - 2410
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Kückmann, Theresa
A1  - Abram, Ulrich
T1  - Silver(I) Complexes of 1,3-Dialkyl-4,5-dimethylimidazol-2-ylidenes and their Use as Precursors for the Synthesis of Rhenium(V) NHC Complexes
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
Y1  - 2007
U6  - http://dx.doi.org/10.1002/zaac.200700021
SN  - 1521-3749
VL  - 633
IS  - 5-6
SP  - 830
EP  - 834
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Schweighöfer, Philip V.
A1  - Abram, Ulrich
T1  - Reactions of [ReOX3(PPh3)2] Complexes (X = Cl, Br) with Phenylacetylene and the Structures of the Products
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
N2  - Oxorhenium(V) complexes [ReOX3(PPh3)2] (X = Cl, Br) react with phenylacetylene under formation of complexes with ylide-type ligands. Compounds of the compositions [ReOCl3(PPh3){C(Ph)C(H)(PPh3)}] (1), [ReOBr3(OPPh3){C(Ph)C(H)(PPh3)}] (2), and [ReOBr3(OPPh3){C(H)C(Ph)(PPh3)}] (3) were isolated and characterized by X-ray diffraction. They contain a ligand, which was formed by a nucleophilic attack of released PPh3 at coordinated phenylacetylene. The structures of the products show that there is no preferable position for this attack. Cleavage of the Re–C bond in 3 and dimerization of the organic ligand resulted in the formation of the [{(PPh3)(H)CC(Ph)}2]2+ cation, which crystallized as its [(ReOBr4)(OReO3)]2– salt.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/zaac.200900478
SN  - 1521-3749
VL  - 636
IS  - 5
SP  - 779
EP  - 783
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Braband, Henrik
A1  - Paulßen, Elisabeth
A1  - Abram, Ulrich
T1  - Nitridorhenium(V) Complexes with 1,3-Dialkyl-4,5-dimethylimidazole-2-ylidenes
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
Y1  - 2006
U6  - http://dx.doi.org/10.1002/zaac.200600002
SN  - 1521-3749
VL  - 632
IS  - 6
SP  - 1051
EP  - 1056
ER  - 
TY  - CHAP
A1  - Tippkötter, Nils
A1  - Roikaew, W.
A1  - Ulber, R.
T1  - An automated pilot plant for the bioengineering processing of concentrated whey
T2  - European BioPerspectives : in cooperation with BIOTECHNICA 2008 : 7 - 9 October 2008 Hannover, Germany ; book of abstracts ; abstracts, poster programme
Y1  - 2008
SP  - 98
PB  - Dechema
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Tippkötter, Nils
A1  - Stückmann, H.
A1  - Winkelmann, G.
A1  - Noack, U.
A1  - Beutel, S.
A1  - Scheper, T.
A1  - Ulber, R.
T1  - Optimisation of antibody-labelling of gold colloids for their application in an immunchromatographic assay for microcystin-LR
T2  - European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme
Y1  - 2007
SP  - 126
PB  - Dechema
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Al-Kaidy, H.
A1  - Ulber, R.
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  - Werkhausen, Amelie
A1  - Albracht, Kirsten
A1  - Cronin, Neil J.
A1  - Meier, Rahel
A1  - Mojsen-Moeller, Jens
A1  - Seynnes, Olivier R.
T1  - Modulation of muscle-tendon interaction in the human triceps surae during an energy dissipation task
JF  - Journal of Experimental Biology
Y1  - 2017
U6  - http://dx.doi.org/10.1242/jeb.164111
SN  - 0022-0949
VL  - 220
IS  - 22
SP  - 4141
EP  - 4149
ER  - 
TY  - JOUR
A1  - Demmer, Julius K.
A1  - Chowdhury, Nilanjan Pal
A1  - Selmer, Thorsten
A1  - Ermler, Ulrich
A1  - Buckel, Wolfgang
T1  - The semiquinone swing in the bifurcating electron transferring flavoprotein/butyryl-CoA dehydrogenase complex from Clostridium difficile
JF  - Nature Communications
Y1  - 2017
U6  - http://dx.doi.org/10.1038/s41467-017-01746-3
SN  - 2041-1723
N1  - Article number 1577
VL  - 8
IS  - 1
SP  - 1
EP  - 10
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, Ronald
A1  - Wagner, Torsten
T1  - Investigation of the spatial resolution of a laser-based stimulation process for light-addressable hydrogels with incorporated graphene oxide by means of IR thermography
JF  - Sensors and Actuators A: Physical
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.sna.2017.11.031
SN  - 0924-4247
VL  - 268
SP  - 126
EP  - 132
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Stückmann, Henning
A1  - Kroll, Stephen
A1  - Winkelmann, Gunda
A1  - Noack, Udo
A1  - Scheper, Thomas
A1  - Ulber, Roland
T1  - A semi-quantitative dipstick assay for microcystin
JF  - Analytical and Bioanalytical Chemistry
N2  - An immunochromatographic lateral flow dipstick assay for the fast detection of microcystin-LR was developed. Colloid gold particles with diameters of 40 nm were used as red-colored antibody labels for the visual detection of the antigen. The new dipstick sensor is capable of detecting down to 5 µg·l−1 (ppb; total inversion of the color signal) or 1 ppb (observation of color grading) of microcystin-LR. The course of the labeling reaction was observed via spectrometric wave shifts caused by the change of particle size during the binding of antibodies. Different stabilizing reagents showed that especially bovine serum albumin (BSA) and casein increase the assays sensitivity and the conjugate stability. Performance of the dipsticks was quantified by pattern processing of capture zone CCD images. Storage stability of dipsticks and conjugate suspensions over 115 days under different conditions were monitored. The ready-to-use dipsticks were successfully tested with microcystin-LR-spiked samples of outdoor drinking- and salt water and applied to the tissue of microcystin-fed mussels.
Y1  - 2009
U6  - http://dx.doi.org/10.1007/s00216-009-2750-8
SN  - 1618-2650
VL  - 394
IS  - 3
SP  - 863
EP  - 869
PB  - springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Roikaew, W.
A1  - Ulber, R.
T1  - Nitrate removal from whey concentrate with biotechnological regeneration of the waste water
JF  - European dairy magazine : EDM
Y1  - 2008
SN  - 0936-6318
IS  - 1
SP  - 30
EP  - 32
ER  - 
TY  - PAT
A1  - Stadtmüller, Ralf
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - A method for production of single-stranded nucleic acids [Europäische Patentanmeldung]
Y1  - 2013
PB  - Europäisches Patentamt
CY  - Den Hague
ER  - 
TY  - PAT
A1  - Al-Kaidy, Huschyar
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - A system and a method for the implementation of chemical, biological or physical reactions [Europäische Patentanmeldung]
N2  - The invention relates to a system for the implementation of chemical, biological or physical reactions, consisting of - one or more magnetic micro-reactors, each comprising a shell made of hydrophobic magnetic nanoparticles encapsulating an aqueous core, - a plane platform comprising a surface to receive the micro-reactors, - a source that generates a magnetic field above or underneath the platform for manipulating the one or more hydrophobic magnetic micro-reactors, or for moving them along the surface of the platform from one position to another position, characterized in that the aqueous core of the one or more magnetic micro-reactors contains a reaction solution or buffer, and wherein the magnetic field generated by the source correlates to a defined position on the surface of the platform.
Y1  - 2013
PB  - Europäisches Patentamt
CY  - Den Hague
ER  - 
TY  - CHAP
A1  - Wulfhorst, H.
A1  - Duwe, A.
A1  - Möhring, S.
A1  - Jurca, O.
A1  - Tippkötter, Nils
T1  - Analysis of pretreated biomass by differential scanning 132 calorimetry and multivariate data analysis
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 132
PB  - DECHEMA
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Capitain, C.
A1  - Hering, T.
A1  - Tippkötter, Nils
A1  - Ulber, R.
T1  - Enzymatic polymerization of lignin model compounds and solubilized lignin in an aqueous ethanol extract
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 151
EP  - 152
PB  - DECHEMA
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Möhring, S.
A1  - Wulfhorst, H.
A1  - Roth, J.
A1  - Tippkötter, Nils
T1  - Pretreatment strategies for lignocellulosic biomass
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 131
PB  - DECHEMA
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Roth, J.
A1  - Möhring, S.
A1  - Tippkötter, Nils
T1  - Characterization and evaluation of lignocellulosic biomass 130 hydrolysates for ABE fermentation
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 130
PB  - DECHEMA
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Hering, T.
A1  - Ulber, Roland
A1  - Tippkötter, Nils
T1  - Development of a screening system for antimicrobial surfaces
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 129
PB  - DECHEMA
CY  - Frankfurt am Main
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  - 
TY  - JOUR
A1  - Seifarth, Volker
A1  - Grosse, Joachim O.
A1  - Grossmann, Matthias
A1  - Janke, Heinz Peter
A1  - Arndt, Patrick
A1  - Koch, Sabine
A1  - Epple, Matthias
A1  - Artmann, Gerhard
A1  - Temiz Artmann, Aysegül
T1  - Mechanical induction of bi-directional orientation of primary porcine bladder smooth muscle cells in tubular fibrin-poly(vinylidene fluoride) scaffolds for ureteral and urethral repair using cyclic and focal balloon catheter stimulation
JF  - Journal of Biomaterials Applications
Y1  - 2017
U6  - http://dx.doi.org/10.1177/0885328217723178
SN  - 1530-8022
VL  - 32
IS  - 3
SP  - 321
EP  - 330
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Yazici, Yasemen
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of an amperometric biosensor array for simultaneous measurement of ethanol, formate, d- and l-lactate
JF  - Electrochimica Acta
N2  - The immobilization of NAD+-dependent dehydrogenases, in combination with a diaphorase, enables the facile development of multiparametric sensing devices. In this work, an amperometric biosensor array for simultaneous determination of ethanol, formate, d- and l-lactate is presented. Enzyme immobilization on platinum thin-film electrodes was realized by chemical cross-linking with glutaraldehyde. The optimization of the sensor performance was investigated with regard to enzyme loading, glutaraldehyde concentration, pH, cofactor concentration and temperature. Under optimal working conditions (potassium phosphate buffer with pH 7.5, 2.5 mmol L-1 NAD+, 2.0 mmol L-1 ferricyanide, 25 °C and 0.4% glutaraldehyde) the linear working range and sensitivity of the four sensor elements was improved. Simultaneous and cross-talk free measurements of four different metabolic parameters were performed successfully. The reliable analytical performance of the biosensor array was demonstrated by application in a clarified sample of inoculum sludge. Thereby, a promising approach for on-site monitoring of fermentation processes is provided.
KW  - Simultaneous determination
KW  - Enzymatic biosensor
KW  - Diaphorase
KW  - Dehydrogenase
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.electacta.2017.07.119
SN  - 0013-4686
VL  - 251
SP  - 256
EP  - 262
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Röhlen, Desiree
A1  - Pilas, Johanna
A1  - Schöning, Michael Josef
A1  - Selmer, Thorsten
T1  - Development of an amperometric biosensor platform for the combined determination of l-Malic, Fumaric, and l-Aspartic acid
JF  - Applied Biochemistry and Biotechnology
N2  - Three amperometric biosensors have been developed for the detection of L-malic acid, fumaric acid, and L -aspartic acid, all based on the combination of a malate-specific dehydrogenase (MDH, EC 1.1.1.37) and diaphorase (DIA, EC 1.8.1.4). The stepwise expansion of the malate platform with the enzymes fumarate hydratase (FH, EC 4.2.1.2) and aspartate ammonia-lyase (ASPA, EC 4.3.1.1) resulted in multi-enzyme reaction cascades and, thus, augmentation of the substrate spectrum of the sensors. Electrochemical measurements were carried out in presence of the cofactor β-nicotinamide adenine dinucleotide (NAD+) and the redox mediator hexacyanoferrate (III) (HCFIII). The amperometric detection is mediated by oxidation of hexacyanoferrate (II) (HCFII) at an applied potential of + 0.3 V vs. Ag/AgCl. For each biosensor, optimum working conditions were defined by adjustment of cofactor concentrations, buffer pH, and immobilization procedure. Under these improved conditions, amperometric responses were linear up to 3.0 mM for L-malate and fumarate, respectively, with a corresponding sensitivity of 0.7 μA mM−1 (L-malate biosensor) and 0.4 μA mM−1 (fumarate biosensor). The L-aspartate detection system displayed a linear range of 1.0–10.0 mM with a sensitivity of 0.09 μA mM−1. The sensor characteristics suggest that the developed platform provides a promising method for the detection and differentiation of the three substrates.
Y1  - 2017
U6  - http://dx.doi.org/10.1007/s12010-017-2578-1
SN  - 1559-0291
VL  - 183
SP  - 566
EP  - 581
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Muschallik, Lukas
A1  - Molinnus, Denise
A1  - Bongaerts, Johannes
A1  - Pohl, Martina
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Siegert, Petra
A1  - Selmer, Thorsten
T1  - (R,R)-Butane-2,3-diol Dehydrogenase from Bacillus clausii DSM 8716T: Cloning and Expression of the bdhA-Gene, and Initial Characterization of Enzyme
JF  - Journal of Biotechnology
N2  - The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716T was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33–43%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12 U/mg and 23 U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115 U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74 U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD+ was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development.
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.jbiotec.2017.07.020
SN  - 0168-1656
VL  - 258
SP  - 41
EP  - 50
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Duwe, Anna-Maria
A1  - Wiesen, Sebastian
A1  - Sieker, Tim
A1  - Ulber, Roland
T1  - Enzymatic hydrolysis of beech wood lignocellulose at high solid contents and its utilization as substrate for the production of biobutanol and dicarboxylic acids
JF  - Bioresource Technology
N2  - The development of a cost-effective hydrolysis for crude cellulose is an essential part of biorefinery developments. To establish such high solid hydrolysis, a new solid state reactor with static mixing is used. However, concentrations >10% (w/w) cause a rate and yield reduction of enzymatic hydrolysis. By optimizing the synergetic activity of cellulolytic enzymes at solid concentrations of 9%, 17% and 23% (w/w) of crude Organosolv cellulose, glucose concentrations of 57, 113 and 152 g L⁻¹ are reached. However, the glucose yield decreases from 0.81 to 0.72gg⁻¹ at 17% (w/w). Optimal conditions for hydrolysis scale-up under minimal enzyme addition are identified. As result, at 23% (w/w) crude cellulose the glucose yield increases from 0.29 to 0.49gg⁻¹. As proof of its applicability, biobutanol, succinic and itaconic acid are produced with the crude hydrolysate. The potential of the substrate is proven e.g. by a high butanol yield of 0.33gg⁻¹.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.biortech.2014.06.052
VL  - 167
SP  - 447
EP  - 455
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wiesen, Sebastian
A1  - Tippkötter, Nils
A1  - Muffler, Kai
A1  - Suck, Kirstin
A1  - Sohling, Ulrich
A1  - Ruf, Friedrich
A1  - Ulber, Roland
T1  - Adsorption of fatty acids to layered double hydroxides in aqueous systems
JF  - Adsorption
N2  - Due to their anion exchange characteristics, layered double hydroxides (LDHs) are suitable for the detoxification of aqueous, fatty acid containing fermentation substrates. The aim of this study is to examine the adsorption mechanism, using crude glycerol from plant oil esterification as a model system. Changes in the intercalation structure in relation to the amount of fatty acids adsorbed are monitored by X-ray diffraction and infra-red spectroscopy. Additionally, calcination of LDH is investigated in order to increase the binding capacity for fatty acids. Our data propose that, at ambient temperature, fatty acids can be bound to the hydrotalcite by adsorption or in addition by intercalation, depending on fatty acid concentration. The adsorption of fatty acids from crude glycerol shows a BET-like behavior. Above a fatty acid concentration of 3.5 g L−1, intercalation of fatty acids can be shown by the appearance of an increased interlayer spacing. This observation suggests a two phase adsorption process. Calcination of LDHs allows increasing the binding capacity for fatty acids by more than six times, mainly by reduction of structural CO32−.
Y1  - 2015
VL  - 21
IS  - 6-7
SP  - 459
EP  - 466
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wulfhorst, Helene
A1  - Duwe, Anna-Maria
A1  - Merseburg, Johannes
A1  - Tippkötter, Nils
T1  - Compositional analysis of pretreated (beech) wood using differential scanning calorimetry and multivariate data analysis
JF  - Tetrahedron
N2  - The composition of plant biomass varies depending on the feedstock and pre-treatment conditions and influences its processing in biorefineries. In order to ensure optimal process conditions, the quantitative proportion of the main polymeric components of the pre-treated biomass has to be determined. Current standard procedures for biomass compositional analysis are complex, the measurements are afflicted with errors and therefore often not comparable. Hence, new powerful analytical methods are urgently required to characterize biomass. In this contribution, Differential Scanning Calorimetry (DSC) was applied in combination with multivariate data analysis (MVA) to detect the cellulose content of the plant biomass pretreated by Liquid Hot Water (LHW) and Organosolv processes under various conditions. Unlike conventional techniques, the developed analytic method enables the accurate quantification of monosaccharide content of the plant biomass without any previous sample preparation. It is easy to handle and avoids errors in sample preparation.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.tet.2016.04.029
VL  - 72
IS  - 46
SP  - 7329
EP  - 7334
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Al-Kaidy, Huschyar
A1  - Kuthan, Kai
A1  - Hering, Thomas
A1  - Tippkötter, Nils
T1  - Aqueous droplets used as enzymatic microreactors and their electromagnetic actuation
JF  - Journal of Visualized Experiments
N2  - For the successful implementation of microfluidic reaction systems, such as PCR and electrophoresis, the movement of small liquid volumes is essential. In conventional lab-on-a-chip-platforms, solvents and samples are passed through defined microfluidic channels with complex flow control installations. The droplet actuation platform presented here is a promising alternative. With it, it is possible to move a liquid drop (microreactor) on a planar surface of a reaction platform (lab-in-a-drop). The actuation of microreactors on the hydrophobic surface of the platform is based on the use of magnetic forces acting on the outer shell of the liquid drops which is made of a thin layer of superhydrophobic magnetite particles. The hydrophobic surface of the platform is needed to avoid any contact between the liquid core and the surface to allow a smooth movement of the microreactor. On the platform, one or more microreactors with volumes of 10 µL can be positioned and moved simultaneously. The platform itself consists of a 3 x 3 matrix of electrical double coils which accommodate either neodymium or iron cores. The magnetic field gradients are automatically controlled. By variation of the magnetic field gradients, the microreactors' magnetic hydrophobic shell can be manipulated automatically to move the microreactor or open the shell reversibly. Reactions of substrates and corresponding enzymes can be initiated by merging the microreactors or bringing them into contact with surface immobilized catalysts.
Y1  - 2016
U6  - http://dx.doi.org/10.3791/54643
SN  - 1940-087X
IS  - Issue 126
ER  - 
TY  - CHAP
A1  - Poth, Sebastian
A1  - Monzon, Magaly
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Lignocellulosic biorefinery : process integration of hydrolysis and fermentation
T2  - Proceedings / 11th European Workshop on Lignocellulosics and Pulp : August 16 - 19, 2010, Hamburg, Germany
Y1  - 2010
SP  - 65
EP  - 68
PB  - vTi
CY  - Hamburg
ER  - 
TY  - CHAP
A1  - Muffler, Kai
A1  - Tippkötter, Nils
A1  - Ulber, Roland
ED  - Timmis, Kenneth N.
T1  - Chemical feedstocks and fine chemicals from other substrates
T2  - Handbook of hydrocarbon and lipid microbiology. Volume 4:  Consequences of microbial interactions with hydrocarbons, oils and lipids. - (Springer reference)
Y1  - 2010
SN  - 978-3-540-77588-1
U6  - http://dx.doi.org/10.1007%2F978-3-540-77587-4_214
SP  - 2891
EP  - 2902
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Muffler, Kai
A1  - Poth, Sabastian
A1  - Sieker, Tim
A1  - Tippkötter, Nils
A1  - Ulber, Roland
A1  - Sell, Dieter
ED  - Moo-Young, Murray
T1  - Bio-feedstocks
T2  - Comprehensive biotechnology : principles and practices in industry, agcriculture, medicine and the environment. Volume 2: Engineering fundamentals of biotechnology
Y1  - 2011
SN  - 978-0-444-53352-4
U6  - http://dx.doi.org/10.1016/B978-0-08-088504-9.00088-X
SP  - 93
EP  - 101
PB  - Elsevier
CY  - Amsterdam
ET  - 2. edition
ER  - 
TY  - CHAP
A1  - Hahn, Thomas
A1  - Kelly, Svenja
A1  - Muffler, Kai
A1  - Tippkötter, Nils
A1  - Ulber, Roland
ED  - Hans-Jörg, Bart
ED  - Pilz, Stephan
T1  - Extraction of lignocellulose and algae for the production of bulk and fine chemicals
T2  - Industrial scale natural products extraction
Y1  - 2011
SN  - 978-3-527-32504-7 (Print)
SN  - 978-3-527-63512-2 (Online)
U6  - http://dx.doi.org/10.1002/9783527635122
SP  - 221
EP  - 245
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Kappler-Tanudyaya, Nathalie
A1  - Schmitt, Heike
A1  - Tippkötter, Nils
A1  - Meyer, Lina
A1  - Lenzen, Sigurd
A1  - Ulber, Roland
T1  - Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose
JF  - Biotechnology Journal
N2  - Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently.
Y1  - 2007
U6  - http://dx.doi.org/10.1002/biot.200700004
SN  - 1860-7314
VL  - 2
IS  - 6
SP  - 692
EP  - 699
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Deterding, A.
A1  - Ulber, Roland
T1  - Determination of acetic acid in fermentation broth by gas-diffusion technique
JF  - Engineering in Life Sciences
N2  - Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents.
Y1  - 2008
U6  - http://dx.doi.org/10.1002/elsc.200820227
VL  - 8
IS  - 1, Special Issue: Technical Systems for the Use in Life Sciences
SP  - 62
EP  - 67
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Roikaew, Wipa
A1  - Ulber, Roland
A1  - Hoffmann, Alexander
A1  - Denzler, Hans-Jörg
A1  - Buchholz, Heinrich
T1  - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food
JF  - Biotechnology Progress
N2  - Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/btpr.384
SN  - 8756-7938
VL  - 26
IS  - 3
SP  - 756
EP  - 762
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Poth, Sebastian
A1  - Monzon, Magaly
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Lignocellulosic biorefinery: Process integration of hydrolysis and fermentation (SSF process)
JF  - Holzforschung
N2  - The aim of the present work is the process integration and the optimization of the enzymatic hydrolysis of wood and the following fermentation of the products to ethanol. The substrate is a fiber fraction obtained by organosolv pre-treatment of beech wood. For the ethanol production, a co-fermentation by two different yeasts (Saccharomyces cerevisiae and Pachysolen tannophilus) was carried out to convert glucose as well as xylose. Two approaches has been followed: 1. A two step process, in which the hydrolysis of the fiber fraction and the fermentation to product are separated from each other. 2. A process, in which the hydrolysis and the fermentation are carried out in one single process step as simultaneous saccharification and fermentation (SSF). Following the first approach, a yield of about 0.15 g ethanol per gram substrate can be reached. Based on the SSF, one process step can be saved, and additionally, the gained yield can be raised up to 0.3 g ethanol per gram substrate.
Y1  - 2011
N1  - 11th EWLP, Hamburg, Germany, August 16–19, 2010
VL  - 65
IS  - 5
SP  - 633
EP  - 637
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Sieker, Tim
A1  - Neuner, Andreas
A1  - Dimitrova, Darina
A1  - Tippkötter, Nils
A1  - Muffler, Kai
A1  - Bart, Hans-Jörg
A1  - Heinzle, Elmar
A1  - Ulber, Roland
T1  - Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development
JF  - Engineering in Life Sciences
N2  - Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step.
Y1  - 2011
U6  - http://dx.doi.org/10.1002/elsc.201000160
N1  - Special Issue "Bioprocess‐oriented plant design"
VL  - 11
IS  - 4
SP  - 436
EP  - 442
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Al-Kaidy, Huschyar
A1  - Wollny, Steffen
A1  - Ulber, Roland
T1  - Functionalized magnetizable particles for downstream processing in single-use systems
JF  - Chemie Ingenieur Technik
N2  - Biotechnological downstream processing is usually an elaborate procedure, requiring a multitude of unit operations to isolate the target component. Besides the disadvantageous space-time yield, the risks of cross-contaminations and product loss grow fast with the complexity of the isolation procedure. A significant reduction of unit operations can be achieved by application of magnetic particles, especially if these are functionalized with affinity ligands. As magnetic susceptible materials are highly uncommon in biotechnological processes, target binding and selective separation of such particles from fermentation or reactions broths can be done in a single step. Since the magnetizable particles can be produced from iron salts and low priced polymers, a single-use implementation of these systems is highly conceivable. In this article, the principles of magnetizable particles, their synthesis and functionalization are explained. Furthermore, applications in the area of reaction engineering, microfluidics and downstream processing are discussed focusing on established single-use technologies and development potential.
Y1  - 2013
U6  - http://dx.doi.org/10.1002/cite.201200130
VL  - 85
IS  - 1-2: Special Issue: Single-Use Technology
SP  - 76
EP  - 86
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Thiel, Alexander
A1  - Tippkötter, Nils
A1  - Suck, Kirstin
A1  - Sohling, Ulrich
A1  - Ruf, Friedrich
A1  - Ulber, Roland
T1  - New zeolite adsorbents for downstream processing of polyphenols from renewable resources
JF  - Engineering in Life Sciences
N2  - Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources.
Y1  - 2013
U6  - http://dx.doi.org/10.1002/elsc.201200188
VL  - 13
IS  - 3
SP  - 239
EP  - 246
PB  - Wiley
CY  - Weinheim
ER  -