P113: Choosing the right selective pressure: The evolutionary engineering of Saccaromyces cerevisiae for increased production of carotenoids

Carotenoids are a class of tetraterpenoid pigments naturally produced by plants and some fungi and bacteria.  Antioxidant properties of such compounds have potential positive impact on human health, and they are currently used in the nutraceutical industry as supplements, in fortified foods and cosmetics with a total market value estimated around $1.2 billions in 2010 (BCC Research published Sept 2011).  Chemical synthesis is currently not a viable option to produce most carotenoids due to their structural complexity.  Microbial-based production of carotenoids has been amply explored using biosynthetic routes via metabolic engineering and synthetic biology approaches.


Here we showed the development of an experimental adaptive laboratory evolution approach to improve carotenoids production in an engineered Saccharomyces cerevisiae carotenoids producing strain.  By exploiting the antioxidant properties of carotenoids, we were able to design the proper selective pressure for use in adaptive evolution of the strain to allow the coupling of biosynthetic production of secondary metabolites with growth related process.  Carotenoids production was increased by more than 200% compared to the non-evolved parental strain. Transcriptomics and genomics analyses were used to identify the genotypic modifications related with increased productivity.