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Item type:Project, Access status: without files , SPP 2240: Chemoenzymatic reaction cascade in an All-in-One electrochemical system with in situ supply of H2O2 for biosynthesis in aqueous and organic mediaChemoenzymatic reaction cascades have a great potential for biosynthesis and sustainability, especially when coupled with the latest advances in electrochemical systems and material sciences. This envisaged project connects the expertise of three truly interdisciplinary groups in biocatalysis, bioprocess engineering, bioelectrochemical systems (BES) and nano-materials in a unique way to address fundamental challenges in developing a novel and individually optimizable platform for hydrogen peroxide-dependent enzymatic cascade reactions. H2O2 plays an important role as a green and powerful co-substrate or co-factor in the biosynthesis of a vast variety of value-added products and can be electrochemically efficiently generated from H2O and O2 as demonstrated in conventional BES with three-electrodes. One of the first objectives of this project is to develop a fully controllable BES for in situ and on-demand synthesis of H2O2 based on a novel All-in-One (AiO) electrode developed recently by one of the project partners. To realize a controlled H2O2 generation in the AiO electrode with high energy efficiency, highly porous carbon foams coated with carbon nanotubes (CNTs) will be designed and tailored by a sophisticated novel CVD process, yielding low density (20 mg/cm3) and high conductive hierarchical porous structure. H2O2 generated in such a controlled way is instantly used by enzymatic oxyfunctionalization in multistep chemoenzymatic reaction cascades. The reaction systems aimed at will include a peroxidase catalyzed sequential hydroxylation towards the synthesis of hydroquinone in aqueous media as well as the simultaneous chemoenzymatic esterification and epoxidation towards epoxidized fatty acid esters in a solvent free organic environment (adapted Prilezhaev reaction). The mentioned reactions will be investigated using both free and immobilized enzymes on functionalized CNTs. This integrated approach is unique and promising in tackling one of the major issues in H2O2 -dependent enzymatic oxyfunctionalization, namely the lowered half-life time of enzyme activity in the presence of H2O2. By integrating the AiO-electrode in an organic reaction medium in situ H2O2 addition will be realized without the addition of water, omitting side reactions (e.g. in the Prilezhaev reaction). With a fine-tunable system in hand, the rates of electrochemical H2O2 synthesis and enzymatic H2O2 consumption can be tightly coupled, enabling a constantly low concentration of H2O2 during the whole cascade reaction. This will open up new possibilities to develop chemoenzymatic reaction cascades with improved enzyme stability and activity and a more stable entire process.316 - Some of the metrics are blocked by yourconsent settings
Item type:Project, Access status: without files , Development of reaction systems for ATP regeneration from the inexpensive bulk chemical ethylene glycolIn this project, enzyme systems for the cost-effective regeneration of ATP in technical reaction systems will be developed. The project is planned as a joint project of the working groups of Prof. Thomas Walther (Professorship of Bioprocess Engineering, TU Dresden) and of Prof. Andreas Liese (Chair of Technical Biocatalysis, TU Hamburg), where AG Walther is responsible for the design and construction of the ATP regenerating enzyme cascades as well as for the optimization of individual enzyme activities, and the AG Liese will work on the reaction engineering and optimization of the reaction systems as well as transfer to larger scales.ATP regenerating reaction systems have a variety of industrial applications. Examples include the synthesis of phosphorylated fine chemicals, syntheses with phosphorylation as an intermediate step and cell-free protein expression. A major obstacle to the commercialization of ATP-dependent, cell-free, product syntheses is the sometimes very high price of the substrates and cofactors used for ATP regeneration.To solve this technical problem, the development of reaction systems is proposed, which allow an ATP regeneration of the low-cost and potentially "green" bulk chemical ethylene glycol. The implementation of the designed enzyme cascades requires the enhancement of enzyme activity on a non-natural substrate. This increase in activity is to be achieved through a combination of rational and evolutionary protein design. In addition, a reaction-technical analysis and optimization of the transfer of the various systems on a technical scale is examined.The enzyme cascades for the regeneration of ATP will be constructed from isolated enzymes as well as be implemented in whole-cell biocatalysts. In each case, the ATP-regenerating systems are coupled to the synthesis of an ATP-consuming reaction for the synthesis of a phosphorylated or non-phosphorylated end product in order to determine advantages and limits of both design variants.The reaction cascades described have the potential to be developed into a new universal ATP regeneration system, which can also be used on an industrial scale.89 - Some of the metrics are blocked by yourconsent settings
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