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 - Becht, Alexander A1 - Schollmayer, Curd A1 - Monakhova, Yulia A1 - Holzgrabe, Ulrike T1 - Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis JF - Analytical and Bioanalytical Chemistry N2 - Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer. KW - IR KW - Manufacturer KW - Linear discriminant analysis KW - Principal component analysis Y1 - 2021 U6 - https://doi.org/10.1007/s00216-021-03249-z SN - 1618-2650 VL - 413 SP - 3107 EP - 3118 PB - Springer Nature ER - TY - JOUR A1 - Lindner, Simon A1 - Burger, René A1 - Rutledge, Douglas N. A1 - Do, Xuan Tung A1 - Rumpf, Jessica A1 - Diehl, Bernd W. K. A1 - Schulze, Margit A1 - Monakhova, Yulia T1 - Is the calibration transfer of multivariate calibration models between high- and low-field NMR instruments possible? A case study of lignin molecular weight JF - Analytical chemistry N2 - Although several successful applications of benchtop nuclear magnetic resonance (NMR) spectroscopy in quantitative mixture analysis exist, the possibility of calibration transfer remains mostly unexplored, especially between high- and low-field NMR. This study investigates for the first time the calibration transfer of partial least squares regressions [weight average molecular weight (Mw) of lignin] between high-field (600 MHz) NMR and benchtop NMR devices (43 and 60 MHz). For the transfer, piecewise direct standardization, calibration transfer based on canonical correlation analysis, and transfer via the extreme learning machine auto-encoder method are employed. Despite the immense resolution difference between high-field and low-field NMR instruments, the results demonstrate that the calibration transfer from high- to low-field is feasible in the case of a physical property, namely, the molecular weight, achieving validation errors close to the original calibration (down to only 1.2 times higher root mean square errors). These results introduce new perspectives for applications of benchtop NMR, in which existing calibrations from expensive high-field instruments can be transferred to cheaper benchtop instruments to economize. Y1 - 2022 SN - 1520-6882 U6 - https://doi.org/10.1021/acs.analchem.1c05125 VL - 94 IS - 9 SP - 3997 EP - 4004 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Aboulnaga, Elhussiny A. A1 - Zou, Huibin A1 - Selmer, Thorsten A1 - Xian, Mo 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 - https://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 - Aggarwal, Pranav A1 - Dhiman, Shashi K. A1 - Kumar, G. A1 - Scherer, Ulrich W. A1 - Singla, M. L. A1 - Srivastava, Alok 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 - Srivastava, Alok A1 - Singh, Virendra A1 - Aggarwal, Pranav A1 - Schneeweiss, F. A1 - Scherer, Ulrich W. A1 - Friedrich, W. T1 - Optical studies of insulating polymers for radiation dose monitoring JF - Indian Journal of Pure & Applied Physics Y1 - 2010 SN - 0019-5596 N1 - Special Issue: SI VL - 48 IS - 11 SP - 782 EP - 786 ER - TY - GEN A1 - Roth, J. A1 - Tippkötter, Nils T1 - New Approach for Enzymatic Hydrolysis of Lignocellulose with Selective Diffusion Separation of the Monosaccharide Products T2 - Chemie Ingenieur Technik N2 - Enzymatic hydrolysis of lignocellulosic material plays an important role in the classical biorefinery approach. Apart from the pretreatment of the raw material, hydrolysis is the basis for the conversion of the cellulose and hemicellulose fraction into fermentable sugars. After hydrolysis, usually a solid-liquid separation takes place, in order to separate the residual plant material from the sugar-rich fraction, which can be subsequently used in a fermentation step. In order to factor out the separation step, the usage of in alginate immobilized crude cellulose fiber beads (CFBs) were evaluated. Pretreated cellulose fibers are incorporated in an alginate matrix together with the relevant enzymes. In doing so, sugars diffuse trough the alginate matrix, allowing a simplified delivery into the surrounding fluid. This again reduces product inhibition of the glucose on the enzyme catalysts. By means of standardized bead production the hydrolysis in lab scale was possible. First results show that liberation of glucose and xylose is possible, allowing a maximum total sugar yield of 75 %. Y1 - 2016 U6 - https://doi.org/10.1002/cite.201650301 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet-Jahrestagung 2016 und 32. DECHEMA-Jahrestagung der Biotechnologen 2016, 12. - 15. September 2016, Eurogress Aachen VL - 88 IS - 9 SP - 1237 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Oehlenschläger, Katharina A1 - Volkmar, Marianne A1 - Stiefelmaier, Judith A1 - Langsdorf, Alexander A1 - Holtmann, Dirk A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum JF - Applied Microbiology and Biotechnology N2 - Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured. KW - Pre-culture KW - Metabolic shift KW - Acid crash KW - C. acetobutylicum KW - ABE KW - Butanol Y1 - 2024 U6 - https://doi.org/10.1007/s00253-023-12981-8 SN - 1432-0614 VL - 108 PB - Springer CY - Berlin, Heidelberg ER - TY - CHAP A1 - Kalbe, Jochen A1 - Kuropka, Rolf A1 - Meyer-Stork, L. Sebastian A1 - Lauter, S. L. A1 - Höcker, Hartwig A1 - Berndt, Heinz ED - Körner, Andrea T1 - Identification of fine animal hair via DNA analysis T2 - Proceedings of the 1st International Symposium on Specialty Animal Fibers : Aachen, October 26 - 27, 1987 ; [scientific, technological and economical aspects] . - (Schriftenreihe des Deutschen Wollforschungsinstitutes an der Technischen Hochschule Aachen e.V. ; 103) Y1 - 1988 SN - 0930-3723 SP - 221 EP - 227 PB - Dt. Wollforschungsinst. CY - Aachen ER - TY - JOUR A1 - Krüger, Götz A1 - Grötzinger, Joachim A1 - Berndt, Heinz T1 - Enantiomeric resolution of amino acid derivatives on chiral stationary phases by high-performance liquid chromatography JF - Journal of Chromatography A Y1 - 1987 U6 - https://doi.org/10.1016/S0021-9673(01)85005-6 SN - 0021-9673 VL - 1987 IS - 397 SP - 223 EP - 232 ER -