Antarctic thraustochytrids: Producers of long‐chain omega‐3 polyunsaturated fatty acids

• Published in: MicrobiologyOpen
• Main Authors: Carolina Shene, Paris Paredes, Daniela Vergara, Allison Leyton, Marcelo Garcés, Liset Flores, Mónica Rubilar, Mariela Bustamante, Roberto Armenta
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: docosahexaenoic acid; eicosapentaenoic acid; lipids; marine microorganisms; polyunsaturated fatty acids; Thraustochytriidae; Microbiology; QR1-502; Antarctic; Escudero; The Antarctic; Antarc*; Antarctica
• Online Access: https://doi.org/10.1002/mbo3.950; https://doaj.org/article/6a34f4c8dc004f9fb9745fe6daf9881e

Abstract Thraustochytrids have been isolated from different aquatic systems; however, few studies have reported their occurrence in Antarctica. In this study, 13 strains close to strains belonging to the genera Oblongichytrium, Thraustochytrium, and Aurantiochytrium were isolated from seawater samples collected near the Antarctic Base Professor Julio Escudero (S 62°12′57′ E 58°57′35″). Docosahexaenoic acid (DHA) was found in the total lipids of all the isolates; DHA content of the biomass (dry weight) varied between 3.3 and 33 mg/g under the growth conditions for isolation. Five of the Antarctic thraustochytrids were able to accumulate lipids at levels higher than 20% w/w. Two strains, RT2316‐7 and RT2316‐13, were selected to test the effect of the incubation temperature (at 5°C for 14 days and at 15°C for 5 days). Incubation temperature had little effect on the lipid content and biomass yield; however, its effect on the fatty acid composition was significant (p < .05). The low incubation temperature favored the accumulation of eicosapentaenoic acid (EPA), palmitic acid and stearic acid in the total lipids of RT2316‐7. Percentage of EPA, DHA and the omega‐6 fatty acid dihomo‐γ‐linolenic acid of total fatty acids of RT2316‐13 was higher at the low incubation temperature. RT2316‐13 accumulated the highest lipid content (30.0 ± 0.5%) with a carbon to nitrogen mass ratio equal to 16.9. On the contrary, lipid accumulation in RT2316‐7 occurred at high concentration of the nitrogen sources (monosodium glutamate or yeast extract). The capability to accumulate lipids with a fatty acid profile that can be tuned through cultivation temperature make the Antarctic thraustochytrid RT2316‐13 a candidate for the production of lipids with different uses.