TY  - JOUR
A1  - Engel, Mareike
A1  - Holtmann, Dirk
A1  - Ulber, Roland
A1  - Tippkötter, Nils
T1  - Increased Biobutanol Production by Mediator‐Less Electro‐Fermentation
JF  - Biotechnology Journal
N2  - A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at −600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6% compared to 23.3% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry.
Y1  - 2018
U6  - http://dx.doi.org/10.1002/biot.201800514
SN  - 1860-7314
IS  - Volume 14, Issue 4
SP  - Artikel 1800514
PB  - Wiley-VCH
ER  - 
TY  - JOUR
A1  - Engel, Mareike
A1  - Gemünde, Andre
A1  - Holtmann, Dirk
A1  - Müller-Renno, Christine
A1  - Ziegler, Christiane
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Clostridium acetobutylicum’s connecting world: cell appendage formation in bioelectrochemical systems
JF  - ChemElectroChem
Y1  - 2019
U6  - http://dx.doi.org/10.1002/celc.201901656
SN  - 2196-0216
IS  - Accepted Article
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Engel, Mareike
A1  - Bayer, Hendrik
A1  - Holtmann, Dirk
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Flavin secretion of Clostridium acetobutylicum in a bioelectrochemical system - Is an iron limitation involved?
JF  - Bioelectrochemistry
Y1  - 2019
U6  - http://dx.doi.org/10.1016/j.bioelechem.2019.05.014
SN  - 1567-5394
IS  - In Press, Accepted Manuscript
PB  - Elsevier
CY  - Amsterdam
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  - 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  -