scholarly journals A 13CO2 Enrichment Experiment to Study the Synthesis Pathways of Polyunsaturated Fatty Acids of the Haptophyte Tisochrysis lutea

Marine Drugs ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 22
Author(s):  
Marine Remize ◽  
Frédéric Planchon ◽  
Matthieu Garnier ◽  
Ai Ning Loh ◽  
Fabienne Le Grand ◽  
...  

The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a 13C-enriched isotopic marker, 13CO2, for 24 h during the exponential growth of the algae. The 13C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in 13C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in 13C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the 13C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis.

2006 ◽  
Vol 60 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Silvia Scaglioni ◽  
Elvira Verduci ◽  
Michela Salvioni ◽  
Maria Luisa Biondi ◽  
Giovanni Radaelli ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1220
Author(s):  
Eduard V. Nekrasov ◽  
Vasily I. Svetashev

Young fronds of ferns are consumed as a vegetable in many countries. The aim of this study was to analyze three fern species that are available for sale in the Russian Far East as dietary sources in terms of fatty acids that are important for human physiology: arachidonic acid (20:4n-6, ARA), eicosapentaenoic acid (20:5n-3, EPA) and other valuable long-chain polyunsaturated fatty acids. The content of ARA and EPA was 5.5 and 0.5 mg/g dry weight, respectively, in Pteridium aquilinum, 4.1 and 1.1 in Matteuccia struthiopteris, and 2.2 and 0.8 in Osmundastrum asiaticum. Salted fronds of P. aquilinum contained less these fatty acids than the raw fronds, with a decrease of up to 49% for ARA and 65% for EPA. These losses were less pronounced or even insignificant in dried fronds. Cooked ferns preserved significant portions of the long-chain polyunsaturated fatty acids: cooked P. aquilinum contained 4.4 mg/g dry weight ARA and 0.3 mg/g dry weight EPA. The ferns may provide a supplemental dietary source of these valuable long-chain polyunsaturated fatty acids, especially for vegetarian diets.


Meat Science ◽  
2021 ◽  
Vol 177 ◽  
pp. 108497
Author(s):  
Juan D. Rios-Mera ◽  
Erick Saldaña ◽  
Iliani Patinho ◽  
Miriam M. Selani ◽  
Carmen J. Contreras-Castillo

2014 ◽  
Vol 62 (41) ◽  
pp. 10153-10161 ◽  
Author(s):  
Madlen Stimming ◽  
Christina M. Mesch ◽  
Mathilde Kersting ◽  
Hermann Kalhoff ◽  
Hans Demmelmair ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2453
Author(s):  
Ana M Pinto ◽  
Helen L MacLaughlin ◽  
Wendy L Hall

Low heart rate variability (HRV) is independently associated with increased risk of sudden cardiac death (SCD) and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may exert anti-arrhythmic effects. This study aimed to investigate relationships between dialysis, sleep and 24 h HRV and LC n-3 PUFA status in patients who have recently commenced haemodialysis. A cross-sectional study was conducted in adults aged 40–80 with chronic kidney disease (CKD) stage 5 (n = 45, mean age 58, SD 9, 20 females and 25 males, 39% with type 2 diabetes). Pre-dialysis blood samples were taken to measure erythrocyte and plasma fatty acid composition (wt % fatty acids). Mean erythrocyte omega-3 index was not associated with HRV following adjustment for age, BMI and use of β-blocker medication. Higher ratios of erythrocyte eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) were associated with lower 24 h vagally-mediated beat-to-beat HRV parameters. Higher plasma EPA and docosapentaenoic acid (DPAn-3) were also associated with lower sleep-time and 24 h beat-to-beat variability. In contrast, higher plasma EPA was significantly related to higher overall and longer phase components of 24 h HRV. Further investigation is required to investigate whether patients commencing haemodialysis may have compromised conversion of EPA to DHA, which may impair vagally-mediated regulation of cardiac autonomic function, increasing risk of SCD.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 296
Author(s):  
Manja M. Zec ◽  
Irena Krga ◽  
Ljiljana Stojković ◽  
Maja Živković ◽  
Biljana Pokimica ◽  
...  

Dietary polyphenols promote cardiometabolic health and are linked with long-chain polyunsaturated fatty acids in plasma phospholipids (LC-PUFA). The FADS2 polymorphisms are associated with LC-PUFA metabolism and overweight/obesity. This 4-week study examined the link between polyphenol intake, FADS2 variants (rs174593, rs174616, rs174576) and obesity in 62 overweight adults (BMI ≥ 25), allocated to consume 100 mL daily of either: Aronia juice, a rich source of polyphenols, with 1177.11 mg polyphenols (expressed as gallic acid equivalents)/100 mL (AJ, n = 22), Aronia juice with 294.28 mg polyphenols/100 mL (MJ, n = 20), or nutritionally matched polyphenol-lacking placebo as a control (PLB, n = 20). We analyzed LC-PUFA (% of total pool) by gas chromatography and FADS2 variants by real-time PCR. Four-week changes in LC-PUFA, BMI, and body weight were included in statistical models, controlling for gender and PUFA intake. Only upon AJ and MJ, the presence of FADS2 variant alleles affected changes in linoleic, arachidonic, and eicosapentaenoic acid (EPA). Upon MJ treatment, changes in EPA were inversely linked with changes in BMI (β= −0.73, p = 0.029) and weight gain (β= −2.17, p = 0.024). Only in subjects drinking AJ, the link between changes in EPA and anthropometric indices was modified by the rs174576 variant allele. Our results indicate the interaction between FADS2, fatty acid metabolism, and polyphenol intake in overweight subjects.


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