TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Schweighöfer, Philip V.
A1  - Abram, Ulrich
T1  - Reactions of [ReOX3(PPh3)2] Complexes (X = Cl, Br) with Phenylacetylene and the Structures of the Products
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
N2  - Oxorhenium(V) complexes [ReOX3(PPh3)2] (X = Cl, Br) react with phenylacetylene under formation of complexes with ylide-type ligands. Compounds of the compositions [ReOCl3(PPh3){C(Ph)C(H)(PPh3)}] (1), [ReOBr3(OPPh3){C(Ph)C(H)(PPh3)}] (2), and [ReOBr3(OPPh3){C(H)C(Ph)(PPh3)}] (3) were isolated and characterized by X-ray diffraction. They contain a ligand, which was formed by a nucleophilic attack of released PPh3 at coordinated phenylacetylene. The structures of the products show that there is no preferable position for this attack. Cleavage of the Re–C bond in 3 and dimerization of the organic ligand resulted in the formation of the [{(PPh3)(H)CC(Ph)}2]2+ cation, which crystallized as its [(ReOBr4)(OReO3)]2– salt.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/zaac.200900478
SN  - 1521-3749
VL  - 636
IS  - 5
SP  - 779
EP  - 783
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Alberto, Roger
A1  - Abram, Ulrich
T1  - Synthesis, Characterization, and Structures of R3EOTcO3 Complexes (E = C, Si, Ge, Sn, Pb) and Related Compounds
JF  - Inorganic Chemistry
N2  - AgTcO4 reacts with R3ECl compounds (E = C, Si, Ge, Sn, Pb; R = Me, iPr, tBu, Ph), tBu2SnCl2, or PhMgCl under formation of novel trioxotechnetium(VII) derivatives. The carbon and silicon derivatives readily undergo decomposition, which was proven by 99Tc NMR spectroscopy and the isolation of decomposition products such as [TcOCl3(THF)(OH2)]. Compounds [Ph3GeOTcO3], [(THF)Ph3SnOTcO3], [(O3TcO)SntBu2(OH)]2, and [(THF)4Mg(OTcO3)2] are more stable and were isolated in crystalline form and characterized by X-ray diffraction.
Y1  - 2010
U6  - http://dx.doi.org/10.1021/ic1001094
SN  - 1520-510X
VL  - 49
IS  - 7
SP  - 3525
EP  - 3530
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Roikaew, Wipa
A1  - Ulber, Roland
A1  - Hoffmann, Alexander
A1  - Denzler, Hans-Jörg
A1  - Buchholz, Heinrich
T1  - Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food
JF  - Biotechnology Progress
N2  - 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.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/btpr.384
SN  - 8756-7938
VL  - 26
IS  - 3
SP  - 756
EP  - 762
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Degering, Christian
A1  - Eggert, Thorsten
A1  - Puls, Michael
A1  - Bongaerts, Johannes
A1  - Evers, Stefan
A1  - Maurer, Karl-Heinz
A1  - Jaeger, Karl-Erich
T1  - Optimization of protease secretion in Bacillus subtilis and Bacillus licheniformis by screening of homologous and herologous signal peptides
JF  - Applied and environmental microbiology
N2  - Bacillus subtilis and Bacillus licheniformis are widely used for the large-scale industrial production of proteins. These strains can efficiently secrete proteins into the culture medium using the general secretion (Sec) pathway. A characteristic feature of all secreted proteins is their N-terminal signal peptides, which are recognized by the secretion machinery. Here, we have studied the production of an industrially important secreted protease, namely, subtilisin BPN′ from Bacillus amyloliquefaciens. One hundred seventy-three signal peptides originating from B. subtilis and 220 signal peptides from the B. licheniformis type strain were fused to this secretion target and expressed in B. subtilis, and the resulting library was analyzed by high-throughput screening for extracellular proteolytic activity. We have identified a number of signal peptides originating from both organisms which produced significantly increased yield of the secreted protease. Interestingly, we observed that levels of extracellular protease were improved not only in B. subtilis, which was used as the screening host, but also in two different B. licheniformis strains. To date, it is impossible to predict which signal peptide will result in better secretion and thus an improved yield of a given extracellular target protein. Our data show that screening a library consisting of homologous and heterologous signal peptides fused to a target protein can identify more-effective signal peptides, resulting in improved protein export not only in the original screening host but also in different production strains.
Y1  - 2010
U6  - http://dx.doi.org/10.1128/AEM.01146-10
SN  - 1098-5336 (E-Journal); 0003-6919 (Print); 0099-2240 (Print)
VL  - 76
IS  - 19
SP  - 6370
EP  - 6378
PB  - American Society for Microbiology
CY  - Washington, DC
ER  -