Tina Lütke-Eversloh

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The excretion of the aromatic amino acid l-tyrosine was achieved by manipulating three gene targets in the wild-type Escherichia coli K12: The feedback-inhibition-resistant (fbr) derivatives of aroG and tyrA were expressed on a low-copy-number vector, and the TyrR-mediated regulation of the aromatic amino acid biosynthesis was eliminated by deleting the(More)
Solventogenic clostridia are well-known since almost a century due to their unique capability to biosynthesize the solvents acetone and butanol. Based on recently developed genetic engineering tools, a targeted 3-hydroxybutyryl-CoA dehydrogenase (Hbd)-negative mutant of Clostridium acetobutylicum was generated. Interestingly, the entire butyrate/butanol(More)
The biodegradability of microbial polythioesters (PTEs), a novel class of biopolymers which were discovered recently and can be produced by polyhydroxyalkanoate (PHA)-accumulating bacteria, was studied. Using poly(3-hydroxybutyrate-co-3-mercaptopropionate) [poly(3HB-co-3MP)] as sole carbon source for screening, 22 new bacterial strains were isolated and(More)
Clostridial acetone–butanol–ethanol (ABE) fermentation is a natural source for microbial n-butanol production and regained much interest in academia and industry in the past years. Due to the difficult genetic accessibility of Clostridium acetobutylicum and other solventogenic clostridia, successful metabolic engineering approaches are still rare. In this(More)
A novel thermophilic bacterium, strain K14T, capable of degrading poly(3-hydroxybutyrate) as well as copolymers containing 3-hydroxybutyrate and 3-mercaptopropionate linked by thioester bonds, was isolated. 16S rDNA sequence analysis showed that strain DhA-71, a dehydroabietic acid-degrading bacterium, was the nearest phylogenetic neighbour and that both(More)
The biosynthesis of the solvents 1-butanol and acetone is restricted to species of the genus Clostridium, a diverse group of Gram-positive, endospore forming anaerobes comprising toxin-producing strains as well as terrestrial non-pathogenic species of biotechnological impact. Among solventogenic clostridia, Clostridium acetobutylicum represents the model(More)
The aromatic amino acid l-tyrosine is used as a dietary supplement and has promise as a valuable precursor compound for various industrial and pharmaceutical applications. In contrast to chemical production, biotechnological methods can produce l-tyrosine from biomass feedstocks under environmentally friendly and near carbon-free conditions. In this(More)
Artificial electron carriers have been widely used to shift the solvent ratio toward butanol in acetone-butanol-ethanol (ABE) fermentation of solventogenic clostridia according to decreased hydrogen production. In this study, first insights on the molecular level were gained to explore the effect of methyl viologen addition to cultures of Clostridium(More)
A hitherto unknown copolymer that contains sulfur in the backbone linking 3-hydroxybutyrate and 3-mercaptobutyrate by thioester linkages, poly(3HB-co-3MB), was synthesized by the polyhydroxyalkanoate-(PHA-) accumulating bacterium Ralstonia eutropha, when 3-mercaptobutyric acid was fed as the carbon source in addition to gluconate. The chemical structure of(More)
This is the first report on the biosynthesis of a hitherto unknown, sulfur-containing polyester and also the first report on a bacterial polymer containing sulfur in the backbone. The Gram-negative polyhydroxyalkanoate (PHA)-accumulating bacterium Ralstonia eutropha synthesized a copolymer of 3-hydroxybutyrate and 3-mercaptopropionate, poly(3HB-co-3MP),(More)