Improving heterologous production of phenylpropanoids in Saccharomyces cerevisiae by tackling an unwanted side reaction of Tsc13, an endogenous double-bond reductase

FEMS Yeast Res. 2017 Jan 1;17(1):fox004. doi: 10.1093/femsyr/fox004.


Phenylpropanoids, such as flavonoids and stilbenoids, are of great commercial interest, and their production in Saccharomyces cerevisiae is a very promising strategy. However, to achieve commercially viable production, each step of the process must be optimised. We looked at carbon loss, known to occur in the heterologous flavonoid pathway in yeast, and identified an endogenous enzyme, the enoyl reductase Tsc13, which turned out to be responsible for the accumulation of phloretic acid via reduction of p-coumaroyl-CoA. Tsc13 is an essential enzyme involved in fatty acid synthesis and cannot be deleted. Hence, two approaches were adopted in an attempt to reduce the side activity without disrupting the natural function: site saturation mutagenesis identified a number of amino acid changes which slightly increased flavonoid production but without reducing the formation of the side product. Conversely, the complementation of TSC13 by a plant gene homologue essentially eliminated the unwanted side reaction, while retaining the productivity of phenylpropanoids in a simulated fed batch fermentation.

Keywords: Saccharomyces cerevisiae; TSC13; flavonoids; phloretic acid.

MeSH terms

  • Genes, Essential
  • Heterocyclic Compounds / metabolism*
  • Metabolic Engineering / methods*
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism
  • Oxidoreductases Acting on CH-CH Group Donors / genetics*
  • Oxidoreductases Acting on CH-CH Group Donors / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism*


  • Heterocyclic Compounds
  • Mutant Proteins
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Oxidoreductases Acting on CH-CH Group Donors
  • TSC13 protein, S cerevisiae