Publikationsserver der RWTH Aachen University
Rekombinante Biosynthese von p-Cumarylalkohol in E. coli
Abstract
dc:descriptionThe increasingly scarce availability of fossil raw materials calls for the development of new strategies to ensure the sustainable supply with energy and components for synthesis. Energy and mass bioconversion processes of renewable raw materials can contribute in minimizing the dependence on fossil raw materials and close the gap in energy supply. Currently though, renewable raw materials cannot completely replace fossil raw materials. The emphasis lies more on the concept of using renewable raw materials as a complement to other established petrochemical methods, or to integrate them into these. Aromatic compounds are components used in the synthesis of many chemical products. They are mainly applied in the production of chemical fibers, plastics, synthetic rubber, as well as solvents. Until now, aromatic compounds are mainly produced through the catalytic or thermal processing of coal and petroleum. Lignin is after cellulose the second most available biopolymer in nature, incorporating around 25% of all organically bound carbon. Lignin forms a component of the plant cell wall and can be considered as a natural resource for aromatic compounds. So far though, lignin can hardly be exploited as such a resource, due to significant technical and biotechnological obstacles. This complex heteropolymer is incrusted in plant cell walls and consists mainly of the monolignols p-cumarylalcohol, coniferylalcohol and sinapylalcohol. Additionally, derivatives of these monolignols can also be found. They are linked in a variety of ways within the lignin molecule, which has, so far, made it impossible to yield aromatic monomers from lignin by enzymatic means. Up to now, there are no physical or chemical methods available to extract any aromatic monomers as compounds for synthesis from this heterogenically structured macromolecule. In this thesis, an alternative strategy is presented, by following the opposite route. The recombinant biosynthesis of p-cumarylalcohol, one of the main components of lignin, was achieved by combining single reactions from phenylpropanoid- and lignin biosynthesis pathways. Different genes from microbial and plant origin were combined for this procedure. The use of E. coli as a host in this artificial synthesis pathway provided the advantage that the reaction products could be effectively excreted and accumulated into the medium with practically no losses, as the bacterial cell wall cannot be lignified. With the presentation of this work, it is now possible for the first time to produce p-cumarylalcohol, one of the main components of lignin, by means of a "metabolic engineering".
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2011
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Jansen, Frank
- Contributors dc:contributor
-
- Kreuzaler, Fritz
Subjects
dc:subject × 13Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger