(149e) Genome-Scale Metabolic Model of Chromochloris, an Emerging Model Organism for Sustainable Fuel Production

There is great demand for biofuel replacements of traditional fossil fuels. However, these replacements are generally not economically competitive. One approach to make bioproduction more economical is to engineer organisms which can produce fuels as well as value added molecules. An excellent candidate for this approach is Chromochloris zofingiensis, a eukaryotic algae that can accumulate up to 40% of dry weight in triacylglycerols. C. zofingiensis also naturally produces astaxanthin, a ketocarotenoid with pharmaceutical, nutraceutical, and cosmetic applications, as well as use in food and feed supplements^1-3. Moreover, the astaxanthin produced by C. zofingiensis is worth approximately $7,000 per kilogram. This is significantly more valuable than synthetic astaxanthin, due to stereochemical differences. Due to the possibilities of co-production, C. zofingiensis is an excellent opportunity for economically viable biofuel production. In order to investigate the metabolic capacity of this organism for both fuel and astaxanthin production, we have reconstructed the metabolic network from the published genome. We will present our work to date, including preliminary biomass assessments, and results of simulations to maximize the production of both products.

References

1 Hussein, G., Sankawa, U., Goto, H., Matsumoto, K. & Watanabe, H. Astaxanthin, a Carotenoid with Potential in Human Health and Nutrition. Journal of Natural Products 69, 443-449, doi:10.1021/np050354+ (2006).

2 Yuan, J. P., Peng, J., Yin, K. & Wang, J. H. Potential health‐promoting effects of astaxanthin: A high‐value carotenoid mostly from microalgae. Molecular Nutrition & Food Research 55, 150-165, doi:doi:10.1002/mnfr.201000414 (2011).

3 Liu, J. et al. Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential. Marine Drugs 12, 3487-3515, doi:10.3390/md12063487 (2014).