title: Exploring medium-chain-length polyhydroxyalkanoates production in the engineered yeast Yarrowia lipolytica.
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.
authors.affiliation: School of Life Science, Linyi University, Linyi, 276005, People's Republic of China.
authors.forename: Cuijuan
authors.initials: C
authors.lastname: Gao
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Qi
authors.forename: Catherine
authors.initials: C
authors.lastname: Madzak
authors.forename: Carol Sze Ki
authors.initials: CS
authors.lastname: Lin
mesh_terms: D000217:Acyltransferases / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D005818:Genetic Engineering; D019301:Oleic Acid / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D014304:Triolein / Q000378:metabolism; D025062:Yarrowia / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D054813:Polyhydroxyalkanoates; D014304:Triolein; D019301:Oleic Acid; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase