title: A new labyrinthulid isolate that produces only docosahexaenoic acid.
abstract: We show here that a new labyrinthulid strain, L72, isolated from a fallen leaf in the Seto Inland Sea of Japan, produced only docohexaenoic acid (DHA) among all the long-chain polyunsaturated fatty acids (LCPUFAs). The main fatty acid composition was 16:0 (28.9%), 18:0 (7.2%), 18:1 (5.7%), 18:2 (10.4%), and DHA (45.9%) without any other LCPUFA. The lipid content of the strain was 27.4%. The cells had many lipid bodies, which were densely located in all of the cells. On phylogenetic analysis using the 18S rDNA sequence, the strain was located in the labyrinthulids group, forming a monophyletic group with Labyrinthula sp. (strain s) and Labyrinthuila sp. (strain L59). We further tested the culture optimization of strain L72 to evaluate the ability of the strain to produce DHA. The optimum salt concentration and the temperature of the strain were 100% of artificial seawater and 20 degrees C. Strain L72 could grow well on soybean oil (SBO) or soybean lecithin (SBL) as the carbon source. When 20 g/l of SBL was added to the medium, DHA production reached the maximum amount at 0.67 g/l for 14 d. The two important facts, that the strain can use SBL as the main nutrient and contains only DHA among the LCPUFAs, will be of great advantage for industry.
authors.affiliation: National Institute of Advanced Industrial Science & Technology, Higashi 1-1, Tsukuba Ibaraki 305-8566, Japan. y-kumon@aist.go.jp
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kumon
authors.forename: Rinka
authors.initials: R
authors.lastname: Yokoyama
authors.forename: Zinia
authors.initials: Z
authors.lastname: Haque
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yokochi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Honda
authors.forename: Toro
authors.initials: T
authors.lastname: Nakahara
mesh_terms: D000818:Animals; D002244:Carbon / Q000378:metabolism / Q000494:pharmacology; D002478:Cells, Cultured; D002849:Chromatography, Gas / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D004281:Docosahexaenoic Acids / Q000032:analysis; D056890:Eukaryota / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000096:biosynthesis* / Q000502:physiology; D044007:Moraxellaceae / Q000254:growth & development; D009584:Nitrogen / Q000378:metabolism / Q000494:pharmacology; D010743:Phospholipids / Q000494:pharmacology; D010802:Phylogeny; D012492:Salts / Q000494:pharmacology; D012623:Seawater; D013024:Soybean Oil / Q000494:pharmacology; D013696:Temperature
chemical_list: D003470:Culture Media; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D010743:Phospholipids; D012492:Salts; D004281:Docosahexaenoic Acids; D002244:Carbon; D013024:Soybean Oil; D009584:Nitrogen