title: Heterologous production of dihomo-gamma-linolenic acid in Saccharomyces cerevisiae.
abstract: To make dihomo-gamma-linolenic acid (DGLA) (20:3n-6) in Saccharomyces cerevisiae, we introduced Kluyveromyces lactis Delta12 fatty acid desaturase, rat Delta6 fatty acid desaturase, and rat elongase genes. Because Fad2p is able to convert the endogenous oleic acid to linoleic acid, this allowed DGLA biosynthesis without the need to supply exogenous fatty acids on the media. Medium composition, cultivation temperature, and incubation time were examined to improve the yield of DGLA. Fatty acid content was increased by changing the medium from a standard synthetic dropout medium to a nitrogen-limited minimal medium (NSD). Production of DGLA was higher in the cells grown at 15 degrees C than in those grown at 20 degrees C, and no DGLA production was observed in the cells grown at 30 degrees C. In NSD at 15 degrees C, fatty acid content increased up until day 7 and decreased after day 10. When the cells were grown in NSD for 7 days at 15 degrees C, the yield of DGLA reached 2.19 microg/mg of cells (dry weight) and the composition of DGLA to total fatty acids was 2.74%. To our knowledge, this is the first report describing the production of polyunsaturated fatty acids in S. cerevisiae without supplying the exogenous fatty acids.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 6, Higashi 1-1-1, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yazawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwahashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kamisaka
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kimura
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Aki
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Ono
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uemura
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000378:metabolism*; D000818:Animals; D003470:Culture Media / Q000737:chemistry; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D013696:Temperature
chemical_list: D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D011994:Recombinant Proteins; D044943:Fatty Acid Desaturases; D015126:8,11,14-Eicosatrienoic Acid