Articles by Katharina Köninger in JoVE
Light-driven Enzymatic Decarboxylation Katharina Köninger1, Marius Grote1, Ioannis Zachos1, Frank Hollmann2, Robert Kourist1 1Faculty of Biology and Biotechnology, Ruhr Universität Bochum, 2Biology and Biotechnology, Delft University of Technology We describe a protocol for the light-catalyzed generation of hydrogen peroxide — a cofactor for oxidative transformations.
Other articles by Katharina Köninger on PubMed
Photosynthetic Production of Enantioselective Biocatalysts Microbial Cell Factories. 2015 | Pubmed ID: 25889799 Global resource depletion poses a dramatic threat to our society and creates a strong demand for alternative resources that do not compete with the production of food. Meeting this challenge requires a thorough rethinking of all steps of the value chain regarding their sustainability resource demand and the possibility to substitute current, petrol-based supply-chains with renewable resources. This regards also the production of catalysts for chemical synthesis. Phototrophic microorganisms have attracted considerable attention as a biomanufacturing platform for the sustainable production of chemicals and biofuels. They allow the direct utilization of carbon dioxide and do not compete with food production. Photosynthetic enzyme production of catalysts would be a sustainable supply of these important components of the biotechnological and chemical industries. This paper focuses on the usefulness of recombinant cyanobacteria for the photosynthetic expression of enantioselective catalysts. As a proof of concept, we used the cyanobacterium Synechocystis sp. PCC 6803 for the heterologous expression of two highly enantioselective enzymes.
Recombinant Cyanobacteria for the Asymmetric Reduction of C=C Bonds Fueled by the Biocatalytic Oxidation of Water Angewandte Chemie (International Ed. in English). Apr, 2016 | Pubmed ID: 27029020 A recombinant enoate reductase was expressed in cyanobacteria and used for the light-catalyzed, enantioselective reduction of C=C bonds. The coupling of oxidoreductases to natural photosynthesis allows asymmetric syntheses fueled by the oxidation of water. Bypassing the addition of sacrificial cosubstrates as electron donors significantly improves the atom efficiency and avoids the formation of undesired side products. Crucial factors for product formation are the availability of NADPH and the amount of active enzyme in the cells. The efficiency of the reaction is comparable to typical whole-cell biotransformations in E. coli. Under optimized conditions, a solution of 100 mg prochiral 2-methylmaleimide was reduced to optically pure 2-methylsuccinimide (99 % ee, 80 % yield of isolated product). High product yields and excellent optical purities demonstrate the synthetic usefulness of light-catalyzed whole-cell biotransformations using recombinant cyanobacteria.