title: Grouping newly isolated docosahexaenoic acid-producing thraustochytrids based on their polyunsaturated fatty acid profiles and comparative analysis of 18S rRNA genes.
abstract: Seven strains of marine microbes producing a significant amount of docosahexaenoic acid (DHA; C22:6, n-3) were screened from seawater collected in coastal areas of Japan and Fiji. They accumulate their respective intermediate fatty acids in addition to DHA. There are 5 kinds of polyunsaturated fatty acid (PUFA) profiles which can be described as (1) DHA/docosapentaenoic acid (DPA; C22:5, n-6), (2) DHA/DPA/eicosapentaenoic acid (EPA; C20:5, n-3), (3) DHA/EPA, (4) DHA/DPA/EPA/arachidonic acid (AA; C20:4, n-6), and (5) DHA/DPA/EPA/AA/docosatetraenoic acid (C22:4, n-6). These isolates are proved to be new thraustochytrids by their specific insertion sequences in the 18S rRNA genes. The phylogenetic tree constructed by molecular analysis of 18S rRNA genes from the isolates and typical thraustochytrids shows that strains with the same PUFA profile form each monophyletic cluster. These results suggest that the C20-22 PUFA profile may be applicable as an effective characteristic for grouping thraustochytrids.
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Huang
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Aki
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yokochi
authors.forename: Toro
authors.initials: T
authors.lastname: Nakahara
authors.forename: Daiske
authors.initials: D
authors.lastname: Honda
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawamoto
authors.forename: Seiko
authors.initials: S
authors.lastname: Shigeta
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Ono
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
mesh_terms: D001483:Base Sequence; D016000:Cluster Analysis; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005367:Fiji; D005658:Fungi / Q000145:classification* / Q000235:genetics* / Q000378:metabolism; D007564:Japan; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D012623:Seawater; D017422:Sequence Analysis, DNA
chemical_list: D005231:Fatty Acids, Unsaturated; D012335:RNA, Ribosomal; D004281:Docosahexaenoic Acids