Metabolic Engineering for Improving Vegetable Oils

Synthetic biology’s application to metabolic engineering allows the production of biomolecules of interest for applications for the chemical, agri-food, and pharmaceutical industries. Since its first implementation on a plant with the production of Vitamin A in rice, numerous examples of plant metabolic engineering have arisen, encompassing modifications of vegetable oil yield and composition. Thus, it is feasible to modify the chain length, number, and position of unsaturations of fatty acids, along with incorporating potential additional functional groups, to enhance the oil quality tailored for a specific use. Modifying plant metabolism is often an iterative approach. Its success lies in an in-depth understanding of the metabolic pathway to be modified and of its endogenous regulation, as well as in efficient phenotyping and cloning techniques (e.g., Golden Braid system). While successfully modifying the expression of one single gene is a routine in labs, manipulating several genes at a glance for rerouting plant metabolisms remains a major challenge. The present chapter describes emblematic examples of works in this field (production of biodiesel, bio-based plastics, and fatty fish oil using camelina), which illustrate both the scientific and technical advances, as well as the constraints to be overcome.