Work Package 3
Cyclohexanol Cascade: Whole-cell biocatalysis
Work package Leader: Evonik
The establishment of multi-enzyme cascades is a major challenge for white biotechnology in general. A classical route is to design whole-cell biocatalysts expressing all relevant genes for the cascade in each cell of a host strain. Therefore expression and correct folding of the corresponding proteins/enzymes have to be optimised. Additionally the import of the substrate and the export of the relevant product have to be increased and possible side reactions leading to by-products have to be knocked-out. As oxidation and reduction reactions will be performed within the multi-enzyme cascades, smart recycling systems avoiding cost-intensive feeding of reduction equivalents have to be developed. This is a major prerequisite to point out the potential of modern biooxidation within multi-enzyme-cascades to be competitive to chemical synthesis.
Evonik has a strong expertise in the field of pathway development and metabolic engineering. With the enzymatic tools of our partner UNIMAN and UNIGRAZ a designed cell will be generated converting the substrate to the desired product. A key factor for an efficient substrate conversion and an economically competitive process with excellent space-time yields is the development of an intelligent cofactor-recycling system which will be generated with UNIGRAZ and established in whole-cell biocatalysts. A possible route of cofactor recycling (in cooperation with UNIGRAZ) avoiding the classical approaches like formiat dehydrogenase or glucose dehydrogenase (which both have the problem of consuming molecules) will be tested. The potential of whole-cell biocatalysis compared to the use of resting cells or cell lysates has to be evaluated. In this project the substrate cyclohexanol will be converted during severl enzymatic steps to the the desired final product 6-amino-hexanoic-acid, a nylon precursor.
Afterwards the system is transferred to different groups of substrates including linear alcohols of different chain lengthes (like n-hexanol or dodecanol), multi-branched-, aromatic, secondary- and tertiary alcohols checking the potential of such cascades for relevant substrates generally.
Evonik Industries is a modern industrial group based in Germany with operations around the world. Evonik is a global leader in specialty chemicals. The Chemicals Business Area operates in attractive areas of specialty chemicals. The six business units, grouped in the Technology Specialities, Consumer Solutions, Specialty Materials segments have a diversified product portfolio ranging from high-performance plastics to additives for paints and coatings, from exclusive synthesis to superabsorbers. With around 34 000 employees at more than 100 sites, Evonik has chemical production facilities in 28 countries. More than 80 percent of sales are generated in markets where Evonik is positioned among the leaders and 20 percent of sales come from products, processes and applications developed in the past five years. Evonik is already positioned among the market leaders in more than 80 percent of their activities.
Evonik is placing increasing emphasis on the innovation potential of "white biotechnology." In 2007 opened its Bio Science-to-Business Center in Marl. In this innovative center for white biotechnology, 60 highly qualified employees collaborate with academia and industry to develop new biotechnological products and processes based on renewable raw materials. Over the last few years, Evonik has developed substantial competencies in the area of bioprocesses, notably through its Biotechnology and ProFerm Project Houses. Building on this expertise, the new Science-to-Business Center now develops highly efficient processes based on renewable, as opposed to fossil, raw materials. The Science-to-Business Center will focus on, among other things, research for biopolymers, biomaterials and cosmetic ingredients. Evonik is already well advanced in using bioprocesses to manufacture pharmaceutical amino acids for infusion solutions, amino acids for animal nutrition, and specialty building blocks for drugs.