@article{TippkoetterAlKaidyWollnyetal.2013, author = {Tippk{\"o}tter, Nils and Al-Kaidy, Huschyar and Wollny, Steffen and Ulber, Roland}, title = {Functionalized magnetizable particles for downstream processing in single-use systems}, series = {Chemie Ingenieur Technik}, volume = {85}, journal = {Chemie Ingenieur Technik}, number = {1-2: Special Issue: Single-Use Technology}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/cite.201200130}, pages = {76 -- 86}, year = {2013}, abstract = {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.}, language = {en} } @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} } @article{ThielTippkoetterSucketal.2013, author = {Thiel, Alexander and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland}, title = {New zeolite adsorbents for downstream processing of polyphenols from renewable resources}, series = {Engineering in Life Sciences}, volume = {13}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/elsc.201200188}, pages = {239 -- 246}, year = {2013}, abstract = {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.}, language = {en} } @article{TeumerCapitainRossJonesetal.2018, author = {Teumer, T. and Capitain, C. and Ross-Jones, J. and Tippk{\"o}tter, Nils and R{\"a}dle, M. and Methner, F.-J.}, title = {In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor}, series = {BrewingScience}, volume = {71}, journal = {BrewingScience}, number = {5/6}, publisher = {Fachverlag Hans Carl}, address = {N{\"u}rnberg}, issn = {1613-2041}, pages = {49 -- 55}, year = {2018}, abstract = {In the present work an optical sensor in combination with a spectrally resolved detection device for in-line particle-size-monitoring for quality control in beer production is presented. The principle relies on the size and wavelength dependent backscatter of growing particles in fluids. Measured interference structures of backscattered light are compared with calculated theoretical values, based on Mie-Theory, and fitted with a linear least square method to obtain particle size distributions. For this purpose, a broadband light source in combination with a process-CCD-spectrometer (charge ? coupled device spectrometer) and process adapted fiber optics are used. The goal is the development of an easy and flexible measurement device for in-line-monitoring of particle size. The presented device can be directly installed in product fill tubes or vessels, follows CIP- (cleaning in place) and removes the need of sample taking. A proof of concept and preliminary results, measuring protein precipitation, are presented.}, language = {en} } @article{RoeschKratzHeringetal.2016, author = {R{\"o}sch, C. and Kratz, F. and Hering, T. and Trautmann, S. and Umanskaya, N. and Tippk{\"o}tter, Nils and M{\"u}ller-Renno, C.M. and Ulber, Roland and Hannig, M. and Ziegler, C.}, title = {Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity}, series = {Colloids and Surfaces B: Biointerfaces}, volume = {149}, journal = {Colloids and Surfaces B: Biointerfaces}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.colsurfb.2016.09.048}, pages = {115 -- 121}, year = {2016}, abstract = {The interplay of albumin (BSA) and lysozyme (LYZ) adsorbed simultaneously on titanium was analyzed by gel electrophoresis and BCA assay. It was found that BSA and lysozyme adsorb cooperatively. Additionally, the isoelectric point of the respective protein influences the adsorption. Also, the enzymatic activity of lysozyme and amylase (AMY) in mixtures with BSA was considered with respect to a possible influence of protein-protein interaction on enzyme activity. Indeed, an increase of lysozyme activity in the presence of BSA could be observed. In contrast, BSA does not influence the activity of amylase.}, language = {en} } @incollection{WagemannTippkoetter2018, author = {Wagemann, Kurt and Tippk{\"o}tter, Nils}, title = {Biorefineries: a short introduction}, series = {Biorefineries}, booktitle = {Biorefineries}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-97117-9}, doi = {10.1007/10_2017_4}, pages = {1 -- 11}, year = {2018}, abstract = {The terms bioeconomy and biorefineries are used for a variety of processes and developments. This short introduction is intended to provide a delimitation and clarification of the terminology as well as a classification of current biorefinery concepts. The basic process diagrams of the most important biorefinery types are shown.}, language = {en} } @article{WulfhorstDuweMerseburgetal.2016, author = {Wulfhorst, Helene and Duwe, Anna-Maria and Merseburg, Johannes and Tippk{\"o}tter, Nils}, title = {Compositional analysis of pretreated (beech) wood using differential scanning calorimetry and multivariate data analysis}, series = {Tetrahedron}, volume = {72}, journal = {Tetrahedron}, number = {46}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.tet.2016.04.029}, pages = {7329 -- 7334}, year = {2016}, abstract = {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.}, language = {en} } @article{TippkoetterRoikaewUlber2008, author = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland}, title = {Nitrate removal from whey concentrate with biotechnological regeneration of the waste water}, series = {European dairy magazine : EDM}, journal = {European dairy magazine : EDM}, number = {1}, isbn = {0936-6318}, pages = {30 -- 32}, year = {2008}, language = {en} } @inproceedings{TippkoetterStueckmannWinkelmannetal.2007, author = {Tippk{\"o}tter, Nils and St{\"u}ckmann, H. and Winkelmann, G. and Noack, U. and Beutel, S. and Scheper, T. and Ulber, Roland}, title = {Optimisation of antibody-labelling of gold colloids for their application in an immunchromatographic assay for microcystin-LR}, series = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme}, booktitle = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme}, publisher = {Dechema}, address = {Frankfurt am Main}, pages = {126}, year = {2007}, language = {en} } @article{TippkoetterDeterdingUlber2008, author = {Tippk{\"o}tter, Nils and Deterding, A. and Ulber, Roland}, title = {Determination of acetic acid in fermentation broth by gas-diffusion technique}, series = {Engineering in Life Sciences}, volume = {8}, journal = {Engineering in Life Sciences}, number = {1, Special Issue: Technical Systems for the Use in Life Sciences}, doi = {10.1002/elsc.200820227}, pages = {62 -- 67}, year = {2008}, abstract = {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.}, language = {en} }