Work package 2
Multi-Enzyme Co-Factor Recycling and Redox Cascades
Work package Leader: Graz
Project: Green routes nylon precursors
Partners involved: Graz, Evonik, CLEA, DTU
The traditional route to ε-caprolactam starts with cyclohexanone and requires hydroxylamine to form the oxime and a lot of sulphuric acid for the work up and the Beckman rearrangement. Although improved routes have been developed employing e.g. zeolite as catalysts, the cyclohexanone oxime intermediate has shown toxicity of the erythrocyte, the nasal epithelium, the liver and also mutagenic activity with Salmonella typhimurium strain. Another restriction is the use of organic solvents.
Therefore a biocatalytic alternative was envisioned to use cheap precursors. These transformations can not be done within one step but would require a multi-enzymatic cascade needing less energy, acid and solvent. Part of the cacade are for instance transaminases as well as alcohol dehydrogenases.
Project: Improved amine donors
Partners involved: Graz, DTU, UniMan, RUG
Alanine is a rather common applied amine donor; unfortunately it has same severe drawbacks even when recycled from pyruvate (Scheme below) like a disastrous reaction equilibrium which leads in general to long reaction times or requires a large excess of alanine. The project focuses on the identification of alternative amine donors and if possible to improve the involved enzymes to accept this donor. Improving enzymes can be done by a random approach or by knowledge based approach analysing the crystal structure of the transaminases.
Project: Synthetic cascades
Partners involved: Graz, UniMan, DTU, CLEA, RUG