(620ai) Metabolic Engineering of Saccharomyces Cerevisiae to Produce Long Chain and Medium Chain Fatty Alcohols from Xylose (Rapid Fire)

Metabolic Engineering of Saccharomyces Cerevisiae to Produce Long Chain and Medium Chain Fatty Alcohols from Xylose

Jiayuan Sheng, Weihua Guo, Xueyang Feng*

Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060

Fatty alcohols are important components of a variety of industries which have a 3 billion-dollar market globally¹. Long chain fatty alcohols are mainly used in surfactants, lubricants, detergents, pharmaceuticals and cosmetics while medium chain fatty alcohols could be used as diesel-like biofuels^1,2. We have previously engineered a Saccharomyces cerevisiae strain to produce over 1.1 g/L 1-hexadecanol from glucose by heterogeneously expressing a bird fatty acyl-CoA reductase (FAR) and optimizing the host metabolism³. In this study we introduced a fungal xylose utilization pathway, which is composed of xylose reductase (XR), xylitol dehydrogenase (XDH), and xylulose kinase (XKS), into our engineered S. cerevisiae to produce 1-hexadecanol from xylose, a non-food feedstock. Over 0.4 g/L 1-hexadecanol can be produced by using the native xylose utilization pathway. We further optimized the xylose utilization by combinational promoter engineering and evolutionary engineering, which improved 1-hexadecanol production titer by 200% (from 0.4 g/L to 1.2 g/L). We also successfully engineered S. cerevisiae to produce 1-decanol and 1-dodecanol by introducing the FAR enzyme into the peroxisome to hijack the medium chain fatty acyl-CoA generated from the beta-oxidation pathway. To our best knowledge, this is the first time that long chain and medium chain fatty alcohols were produced in yeast from xylose.

1       Steen, E. J. et al. Microbial production of fatty-acid-derived fuels and chemicals from plant biomass. Nature 463, 559-562, doi:10.1038/nature08721 (2010).

2       Youngquist, J. T. et al. Production of medium chain length fatty alcohols from glucose in Escherichia coli. Metabolic engineering 20, 177-186, doi:10.1016/j.ymben.2013.10.006 (2013).

3       Feng, X., Lian, J. & Zhao, H. Metabolic engineering of Saccharomyces cerevisiae to improve 1-hexadecanol production. Metabolic engineering 27C, 10-19, doi:10.1016/j.ymben.2014.10.001 (2014).