Exploring medium-chain-length polyhydroxyalkanoates production in the engineered yeast Yarrowia lipolytica

J Ind Microbiol Biotechnol. 2015 Sep;42(9):1255-62. doi: 10.1007/s10295-015-1649-y. Epub 2015 Jul 8.

Abstract

Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) are a large class of biopolymers that have attracted extensive attention as renewable and biodegradable bio-plastics. They are naturally synthesized via fatty acid de novo biosynthesis pathway or β-oxidation pathway from Pseudomonads. The unconventional yeast Yarrowia lipolytica has excellent lipid/fatty acid catabolism and anabolism capacity depending of the mode of culture. Nevertheless, it cannot naturally synthesize PHA, as it does not express an intrinsic PHA synthase. Here, we constructed a genetically modified strain of Y. lipolytica by heterologously expressing PhaC1 gene from P. aeruginosa PAO1 with a PTS1 peroxisomal signal. When in single copy, the codon optimized PhaC1 allowed the synthesis of 0.205 % DCW of PHA after 72 h cultivation in YNBD medium containing 0.1 % oleic acid. By using a multi-copy integration strategy, PHA content increased to 2.84 % DCW when the concentration of oleic acid in YNBD was 1.0 %. Furthermore, when the recombinant yeast was grown in the medium containing triolein, PHA accumulated up to 5.0 % DCW with as high as 21.9 g/L DCW, which represented 1.11 g/L in the culture. Our results demonstrated the potential use of Y. lipolytica as a promising microbial cell factory for PHA production using food waste, which contains lipids and other essential nutrients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / biosynthesis*
  • Acyltransferases / genetics
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Genetic Engineering
  • Oleic Acid / metabolism
  • Polyhydroxyalkanoates / biosynthesis*
  • Pseudomonas aeruginosa / enzymology
  • Triolein / metabolism
  • Yarrowia / genetics*
  • Yarrowia / metabolism

Substances

  • Bacterial Proteins
  • Polyhydroxyalkanoates
  • Triolein
  • Oleic Acid
  • Acyltransferases
  • poly(3-hydroxyalkanoic acid) synthase