@misc{StadtmuellerTippkoetterUlber2015, author = {Stadtm{\"u}ller, Ralf and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Method for production of single-stranded macronucleotides}, year = {2015}, abstract = {The invention relates to a method for production of single-stranded macronucleotides by amplifying and ligating an extended monomeric single-stranded target nucleic acid sequence (targetss) into a repetitive cluster of double-stranded target nucleic acid sequences (targetds), and subsequently cloning the construct into a vector (aptagene vector). The aptagene vector is transformed into host cells for replication of the aptagene and isolated in order to optain single-stranded target sequences (targetss). The invention also relates to single-stranded nucleic acids, produced by a method of the invention.}, 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{PasteurTippkoetterKampeisetal.2014, author = {Pasteur, Aline and Tippk{\"o}tter, Nils and Kampeis, Percy and Ulber, Roland}, title = {Optimization of high gradient magnetic separation filter units for the purification of fermentation products}, series = {IEEE TRANSACTIONS ON MAGNETICS}, volume = {50}, journal = {IEEE TRANSACTIONS ON MAGNETICS}, number = {10}, publisher = {IEEE}, address = {New York, NY}, issn = {0018-9464}, doi = {10.1109/TMAG.2014.2325535}, pages = {Artikel 5000607}, year = {2014}, abstract = {High gradient magnetic separation (HGMS) has been established since the early 1970s. A more recent application of these systems is the use in bioprocesses. To integrate the HGMS in a fermentation process, it is necessary to optimize the separation matrix with regard to the magnetic separation characteristics and permeability of the non-magnetizable components of the fermentation broth. As part of the work presented here, a combined fluidic and magnetic force finite element model simulation was created using the software COMSOL Multiphysics and compared with separation experiments. Finally, as optimal lattice orientation of the separation matrix, a transversal rhombohedral arrangement was defined. The high suitability of the new filter matrix has been verified by separation experiments.}, language = {en} } @article{TippkoetterRoikaewUlberetal.2010, author = {Tippk{\"o}tter, Nils and Roikaew, Wipa and Ulber, Roland and Hoffmann, Alexander and Denzler, Hans-J{\"o}rg and Buchholz, Heinrich}, title = {Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food}, series = {Biotechnology Progress}, volume = {26}, journal = {Biotechnology Progress}, number = {3}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {8756-7938}, doi = {10.1002/btpr.384}, pages = {756 -- 762}, year = {2010}, abstract = {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.}, language = {en} } @article{TippkoetterWollnySucketal.2014, author = {Tippk{\"o}tter, Nils and Wollny, Steffen and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland}, title = {Recycling of spent oil bleaching earth as source of glycerol for the anaerobic production of acetone, butanol, and ethanol with Clostridium diolis and lipolytic Clostridium lundense}, series = {Engineering in Life Sciences}, volume = {14}, journal = {Engineering in Life Sciences}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1618-2863}, doi = {10.1002/elsc.201300113}, pages = {425 -- 432}, year = {2014}, abstract = {A major part of edible oil is subjected to bleaching procedures, primarily with minerals applied as adsorbers. Their recycling is currently done either by regaining the oil via organic solvent extraction or by using the spent bleaching earth (SBE) as additive for animal feed, etc. As a new method, the reutilization of the by-product SBE for the microbiologic formation of acetone, butanol, and ethanol (ABE) is presented as proof-of-concept. The SBE was taken from a palm oil cleaning process. The recycling concept is based on the application of lipolytic clostridia strains. Due to considerably long fermentation times, co-fermentation with Candida rugosa and enzymatic hydrolyses of the bound oil with a subsequent clostridia fermentation are shown as alternative routes. Anaerobic fermentations under comparison of different clostridia strains were performed with glycerol media, enzymatically hydrolyzed palm oil and SBE. Solutes, side product compositions and productivities were quantified via HPLC. A successful production of ABE solutes from SBE has been done with a yield of 0.15 g butanol per gram of bound glycerol. Thus, the biotechnological recycling of the waste stream is possible in principle. Inhibition of the substrate suspension has been observed. A chromatographic ion-exchange of substrates increased the biomass concentration.}, language = {en} }