Synthesis of FAEEs from glycerol in engineered Saccharomyces cerevisiae using endogenously produced ethanol by heterologous expression of an unspecific bacterial acyltransferase

Authors

  • Kyung Ok Yu,

    1. School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea; telephone: +82-2-3290-3151; Fax: +82-2-3290-3151
    Search for more papers by this author
  • Ju Jung,

    1. School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea; telephone: +82-2-3290-3151; Fax: +82-2-3290-3151
    Search for more papers by this author
  • Seung Wook Kim,

    1. Department of Chemical and Biological Engineering, Korea University, Seoul, Republic of Korea
    Search for more papers by this author
  • Chul Hwan Park,

    1. Department of Chemical Engineering, Kwangwoon University, Seoul, Republic of Korea
    Search for more papers by this author
  • Sung Ok Han

    Corresponding author
    1. School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea; telephone: +82-2-3290-3151; Fax: +82-2-3290-3151
    • School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea; telephone: +82-2-3290-3151; Fax: +82-2-3290-3151.
    Search for more papers by this author

Abstract

The high price of petroleum-based diesel fuel has led to the development of alternative fuels, such as ethanol. Saccharomyces cerevisiae was metabolically engineered to utilize glycerol as a substrate for ethanol production. For the synthesis of fatty acid ethyl esters (FAEEs) by engineered S. cerevisiae that utilize glycerol as substrate, heterologous expression of an unspecific acyltransferase from Acinetobacter baylyi with glycerol utilizing genes was established. As a result, the engineered YPH499 (pGcyaDak, pGupWs-DgaTCas) strain produced 0.24 g/L FAEEs using endogenous ethanol produced from glycerol. And this study also demonstrated the possibility of increasing FAEE production by enhancing ethanol production by minimizing the synthesis of glycerol. The overall FAEE production in strain YPH499 fps1Δ gpd2Δ (pGcyaDak, pGupWs-DgaTCas) was 2.1-fold more than in YPH499 (pGcyaDak, pGupWs-DgaTCas), with approximately 0.52 g/L FAEEs produced, while nearly 17 g/L of glycerol was consumed. These results clearly indicated that FAEEs were synthesized in engineered S. cerevisiae by esterifying exogenous fatty acids with endogenously produced ethanol from glycerol. This microbial system acts as a platform in applying metabolic engineering that allows the production of FAEEs from cheap and abundant substrates specifically glycerol through the use of endogenous bioethanol. Biotechnol. Bioeng. 2012;109: 110–115. © 2011 Wiley Periodicals, Inc.

Ancillary