Research
| Title： | The ω6 Pathway toward Eicosapentaenoic Acid Biosynthesis outside the Chloroplast in the Industrially Relevant Alga Nannochloropsis oceanica |
|---|---|
| First author： | Zheng, Jie; Shi, Ying; Liang, Zhiwei; Sun, Han; Zhou, Wenguang; Hu, Hanhua; Liu, Jin |
| Journal： | JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY |
| Years： | 2025 |
| DOI： | 10.1021/acs.jafc.5c09450 |
| Abstract： | Nannochloropsis oceanica is an emerging chassis for industrial eicosapentaenoic acid (EPA) production, yet its biosynthesis pathway remains incompletely defined. Here, we delineate the pathway by characterizing three key enzymes: N. oceanica Delta 12 fatty acid desaturase (No Delta 12FAD), N. oceanica Delta 6 fatty acid desaturase (No Delta 6FAD), and N. oceanica Delta 5 fatty acid desaturase (No Delta 5FAD). Functional validation in yeast confirmed their specific desaturation activities, and localization experiments showed they reside outside the plastid of N. oceanica. Genetic manipulation of individual NoFAD genes (knockdown/overexpression) reshaped fatty acid profiles, particularly EPA, while having a minimal effect on the transcription of other EPA biosynthesis genes. Moreover, impairing EPA biosynthesis via NoFAD knockdown diminished the alga's resilience to temperature and light stress, underscoring the role of EPA in stress adaptation. Collectively, our findings offer new insights into EPA biosynthesis in N. oceanica, highlighting its production through the omega 6 pathway via sequential desaturation and elongation steps outside of the chloroplast. |
