Mar. Drugs 2013, 11(12), 5116-5129; doi:10.3390/md11125116
Article

Identification and Functional Characterization of Genes Encoding Omega-3 Polyunsaturated Fatty Acid Biosynthetic Activities from Unicellular Microalgae

Received: 22 September 2013; in revised form: 20 November 2013 / Accepted: 26 November 2013 / Published: 16 December 2013
(This article belongs to the Special Issue Marine Fatty Acids)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: In order to identify novel genes encoding enzymes involved in the biosynthesis of nutritionally important omega-3 long chain polyunsaturated fatty acids, a database search was carried out in the genomes of the unicellular photoautotrophic green alga Ostreococcus RCC809 and cold-water diatom Fragilariopsis cylindrus. The search led to the identification of two putative “front-end” desaturases (Δ6 and Δ4) from Ostreococcus RCC809 and one Δ6-elongase from F. cylindrus. Heterologous expression of putative open reading frames (ORFs) in yeast revealed that the encoded enzyme activities efficiently convert their respective substrates: 54.1% conversion of α-linolenic acid for Δ6-desaturase, 15.1% conversion of 22:5n-3 for Δ4-desaturase and 38.1% conversion of γ-linolenic acid for Δ6-elongase. The Δ6-desaturase from Ostreococcus RCC809 displays a very strong substrate preference resulting in the predominant synthesis of stearidonic acid (C18:4Δ6,9,12,15). These data confirm the functional characterization of omega-3 long chain polyunsaturated fatty acid biosynthetic genes from these two species which have until now not been investigated for such activities. The identification of these new genes will also serve to expand the repertoire of activities available for metabolically engineering the omega-3 trait in heterologous hosts as well as providing better insights into the synthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in marine microalgae.
Keywords: microalgae; omega-3 long chain polyunsaturated fatty acid; desaturases; elongases
PDF Full-text Download PDF Full-Text [343 KB, uploaded 16 December 2013 16:07 CET]

Export to BibTeX |
EndNote


MDPI and ACS Style

Vaezi, R.; Napier, J.A.; Sayanova, O. Identification and Functional Characterization of Genes Encoding Omega-3 Polyunsaturated Fatty Acid Biosynthetic Activities from Unicellular Microalgae. Mar. Drugs 2013, 11, 5116-5129.

AMA Style

Vaezi R, Napier JA, Sayanova O. Identification and Functional Characterization of Genes Encoding Omega-3 Polyunsaturated Fatty Acid Biosynthetic Activities from Unicellular Microalgae. Marine Drugs. 2013; 11(12):5116-5129.

Chicago/Turabian Style

Vaezi, Royah; Napier, Johnathan A.; Sayanova, Olga. 2013. "Identification and Functional Characterization of Genes Encoding Omega-3 Polyunsaturated Fatty Acid Biosynthetic Activities from Unicellular Microalgae." Mar. Drugs 11, no. 12: 5116-5129.

Mar. Drugs EISSN 1660-3397 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert