TY  - JOUR
A1  - Aboulnaga, E. A.
A1  - Zou, H.
A1  - Selmer, Thorsten
A1  - Xian, M.
T1  - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16
JF  - Journal of Biotechnology
N2  - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.jbiotec.2018.03.007
SN  - 0168-1656
VL  - 274
SP  - 15
EP  - 27
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Aboulnaga, E. H.
A1  - Pinkenburg, O.
A1  - Schiffels, Johannes
A1  - El-Refai, A.
A1  - Buckel, W.
A1  - Selmer, Thorsten
T1  - Butyrate production in Escherichia coli: Exploitation of an oxygen tolerant bifurcating butyryl-CoA dehydrogenase/electron transferring flavoprotein complex from Clostridium difficile
JF  - Journal of bacteriology. June 14, 2013
Y1  - 2013
SN  - 1098-5530 (E-Journal) ; 0021-9193 (Print)
SP  - Epub ahead of print
ER  - 
TY  - JOUR
A1  - Abulnaga, El-Hussiny
A1  - Pinkenburg, Olaf
A1  - Schiffels, Johannes
A1  - E-Refai, Ahmed
A1  - Buckel, Wolfgang
A1  - Selmer, Thorsten
T1  - Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli
JF  - Journal of bacteriology
Y1  - 2013
SN  - 1098-5530 [E-Journal]
SN  - 0021-9193 [Print]
VL  - 195
IS  - 16
SP  - 3704
EP  - 3713
ER  - 
TY  - JOUR
A1  - Adels, Klaudia
A1  - Elbers, Gereon
A1  - Diehl, Bernd
A1  - Monakhova, Yulia
T1  - Multicomponent analysis of dietary supplements containing glucosamine and chondroitin: comparative low- and high-field NMR spectroscopic study
JF  - Analytical Sciences
N2  - With the prevalence of glucosamine- and chondroitin-containing dietary supplements for people with osteoarthritis in the marketplace, it is important to have an accurate and reproducible analytical method for the quantitation of these compounds in finished products. NMR spectroscopic method based both on low- (80 MHz) and high- (500–600 MHz) field NMR instrumentation was established, compared and validated for the determination of chondroitin sulfate and glucosamine in dietary supplements. The proposed method was applied for analysis of 20 different dietary supplements. In the majority of cases, quantification results obtained on the low-field NMR spectrometer are similar to those obtained with high-field 500–600 MHz NMR devices. Validation results in terms of accuracy, precision, reproducibility, limit of detection and recovery demonstrated that the developed method is fit for purpose for the marketed products. The NMR method was extended to the analysis of methylsulfonylmethane, adulterant maltodextrin, acetate and inorganic ions. Low-field NMR can be a quicker and cheaper alternative to more expensive high-field NMR measurements for quality control of the investigated dietary supplements. High-field NMR instrumentation can be more favorable for samples with complex composition due to better resolution, simultaneously giving the possibility of analysis of inorganic species such as potassium and chloride.
KW  - Glucosamine
KW  - Chondroitin sulfate
KW  - Polysaccharides
KW  - Dietary supplements
KW  - High-field NMR
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s44211-023-00433-2
SN  - 1348-2246 (Online)
SN  - 0910-6340 (Print)
N1  - Corresponding author: Yulia Monakhova
VL  - 2023
PB  - Springer Verlag
CY  - Cham
ER  - 
TY  - JOUR
A1  - Aggarwal, P.
A1  - Dhiman, S.
A1  - Kumar, G.
A1  - Scherer, Ulrich W.
A1  - Singla, M. L.
A1  - Srivastava, A.
T1  - Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose
JF  - Indian Journal of Pure and Applied Physics
N2  - Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions.
Y1  - 2012
SN  - 0019-5596
VL  - 50
IS  - 2
SP  - 129
EP  - 132
ER  - 
TY  - JOUR
A1  - Aggarwal, Prerna
A1  - Singh, Virendra
A1  - Singh, Arjun
A1  - Scherer, Ulrich W.
A1  - Singh, Tejvir
A1  - Singla, Madan L.
A1  - Srivastava, Alok
T1  - Physico-chemical transformations in swift heavy ion modified poly(ethyleneterephthalate)
JF  - Radiation Physics and Chemistry
Y1  - 2011
SN  - 0969-806X
N1  - In Press, Accepted Manuscript
SP  - 1
EP  - 28
PB  - Pergamon Press
CY  - Oxford
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  - Al-Kaidy, Huschyar
A1  - Duwe, Anna
A1  - Huster, Manuel
A1  - Muffler, Kai
A1  - Schlegel, Christin
A1  - Sieker, Tim
A1  - Stadtmüller, Ralf
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Biotechnologie und Bioverfahrenstechnik – Vom ersten Ullmanns Artikel bis hin zu aktuellen Forschungsthemen
JF  - Chemie Ingenieur Technik
N2  - Biotechnologie und die mit ihr verbundenen technischen Prozesse prägen seit Jahrtausenden die Entwicklung der Menschheit. Ausgehend von empirischen Verfahren, insbesondere zur Herstellung von Lebensmitteln und täglichen Gebrauchsgütern, haben sich diese Disziplinen zu einem der innovativsten Zukunftsfelder entwickelt. Durch das immer detailliertere Verständnis zellulärer Vorgänge können mittlerweile Produktionsstämme gezielt optimiert werden. Im Zusammenspiel mit moderner Prozesstechnik können so eine Vielzahl von Bulk- und Feinchemikalien sowie Pharmazeutika effizient hergestellt werden. In diesem Artikel werden exemplarisch einige der aktuellen Trends vorgestellt.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/cite.201400083
SN  - 0009-286X
VL  - 86
IS  - 12
SP  - 2215
EP  - 2225
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Al-Kaidy, Huschyar
A1  - Duwe, Anna
A1  - Huster, Manuel
A1  - Muffler, Kai
A1  - Schlegel, Christin
A1  - Tim, Sieker
A1  - Stadtmüller, Ralf
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Biotechnology and bioprocess engineering – from the first ullmann's article to recent trends
JF  - ChemBioEng Reviews
N2  - For several thousand years, biotechnology and its associated technical processes have had a great impact on the development of mankind. Based on empirical methods, in particular for the production of foodstuffs and daily commodities, these disciplines have become one of the most innovative future issues. Due to the increasing detailed understanding of cellular processes, production strains can now be optimized. In combination with modern bioprocesses, a variety of bulk and fine chemicals as well as pharmaceuticals can be produced efficiently. In this article, some of the current trends in biotechnology are discussed.
Y1  - 2015
U6  - http://dx.doi.org/10.1002/cben.201500008
VL  - 2
IS  - 3
SP  - 175
EP  - 184
PB  - Wiley
CY  - Weinheim
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  -