The application of modern Synthetic Biology techniques to address the production of nutritional and industrial speciality chemicals

Isoprenoids, also known as terpenoids represent the largest and oldest class of natural products documented. In crop plants intense efforts have been made to increase nutritional isoprenoids such as carotenoids (b-carotene provitamin A) and tocopherols (vitamin E) as a means of nutritional enhancement. Commercially isoprenoids are used in cosmetics and fragrances, and as colorants and nutritional supplements in foods and feeds. The present production platforms are either plants and/or microorganisms. Biosynthetically all isoprenoids are related via a common five carbon building block (isopentenyl pyrophosphate; IPP). Different isoprenoid classes can utilise the same isoprenoid precursors, which are preferentially used or channeled at different developmental stages. Through the creation of enzyme fusions a means of altering/optimising metabolite challenging can been achieved. These fusions which utilise flexible peptide linkers have the potential to optimise the flow of precursors from one class of isoprenoid into the desired products. In effect create an artificial metabolon. Proof of concept work has proven the potential of the system both in terms of enzymatic function and high throughput screening. In the proposed project fusions between isoprenoid enzymes metabolising geranylgeranyl (C20) or farnesyl (C15) diphosphate will be created and tested in plants and yeasts.