Synthetic protein scaffolds for flavonoid production in Saccharomyces cerevisiae

Many secondary plant metabolites, including flavonoids, have valuable bioactive properties for human health. Currently these flavonoids are obtained through plant extraction or chemical synthesis. However, these processes are time consuming, create a huge amount of waste and are dependent on external factors. Microbial production offers a very promising alternative, allowing the production of these high-value products on an industrial scale. Saccharomyces cerevisiae has a long track of industrial use, however, despite the extensive knowledge, many bottlenecks still remain in constructing an industrial relevant strain. For example, the overall yield can be decreased by improper balancing of heterologous pathway genes and loss of intermediates due to side reactions by native enzymes, which can also lead to the accumulation of toxic intermediates. Substrate channelling might aid in overcoming these problems. Combining the different enzymes of the heterologous pathway in a synthetic enzyme complex may improve local substrate availability, thereby improving the efficiency by which intermediates are passed on through the pathway and reducing the possibility of side reactions. By individually balancing the different enzymes an optimised pathway flow can be obtained. We are therefore developing various of this synthetic complexes based on protein scaffolds in order to gain more insight in how these scaffolds help to increase production of flavonoids, thereby searching for guidelines to apply this technique to other interesting metabolites.