Percentage Of Eicosapentaenoic Acid Research Articles

Effects of Gas Composition on the Lipid Oxidation and Fatty Acid Concentration of Tilapia Fillets Treated with In-Package Atmospheric Cold Plasma.

Cold plasma (CP) is a non-thermal preservation technology that has been successfully used to decontaminate and extend the shelf life of aquatic products. However, the preservation effect of CP treatment is determined by several factors, including voltage, time, and gas compositions. Therefore, this study aimed to investigate the effects of gas composition (GasA: 10% O2, 50% N2, 40% CO2; GasB: air; GasC: 30% O2, 30% N2, 40% CO2) on the lipid oxidation of tilapia fillets treated after CP treatment. Changes in the lipid oxidation values, the percentages of fatty acids, and sensory scores were studied during 8 d of refrigerator storage. The results showed that the CP treatment significantly increased all the primary and secondary lipid oxidation values measured in this study, as well as the percentages of saturated fatty acids, but decreased the percentages of unsaturated fatty acids, especially polyunsaturated fatty acids. The lipid oxidation values were significantly increased in the GasC-CP group. After 8 d, clearly increased percentages of saturated fatty acids, a low level of major polyunsaturated fatty acids (especially linoleic (C18:2n-6)), and a decrease in the percentages of eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) were found in GasC-CP; that is, the serious oxidation of lipids was found in the high O2 concentration group. In addition, the sensory score was also lower than that of the hypoxia CP group. Therefore, high O2 concentrations can enhance lipid oxidation and the changes in the fatty acid concentration. Controlling the O2 concentration is reasonable to limit the degree to which lipids are oxidized in tilapia after the in-package CP treatment.

Efficacy of Omega-3 Intake in Managing Dry Eye Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

To explore the efficacy of omega-3 fatty acids (FAs) on patients suffering from dry eye disease (DED), a complex inflammatory condition, we reviewed data from PubMed, Embase, ClinicalTrials.gov, Web of Science, and Cochrane CENTRAL in the past 10 years (2013 to 2023). These sources provided randomized clinical trials (RCTs) that examined the efficacy of omega-3 FAs on DED patients with accessible pre- and post-intervention data, excluding trials with overlapping participants, without omega-3 supplementation, or those lacking placebo control or quantitative assessments. Two independent reviewers extracted data related to dry eye symptom scores, tear break-up time (TBUT), Schirmer's tests, osmolarity, and corneal fluorescein staining (CFS), and the results were analyzed by Comprehensive Meta-Analysis software version 4. We incorporated 19 related RCTs assessed by the Cochrane Risk of Bias tool, encompassing 4246 DED patients with various etiologies. Patients given omega-3 treatment demonstrated more significant improvements in dry eye symptoms (Hedges' g = -1.047; p < 0.001), TBUT [standardized mean difference (SMD) = -0.939; p < 0.001], scores from the Schirmer test (SMD = -0.372; p < 0.001), CFS (SMD = -0.299; p = 0.037), and osmolarity (SMD = -0.721; p < 0.001) compared to those on a placebo regimen. In the meta-regression analysis of DED symptoms, the daily dose of omega-3 (coefficient = -0.0005, p = 0.002), duration of omega-3 intake (coefficient = -0.1399, p = 0.021), and percentage of eicosapentaenoic acid (EPA) (coefficient = -0.0154, p < 0.001) exhibited a significant positive correlation with a reduction in dry eye symptom scores. Apart from CFS, similar trends were noted in TBUT, Schirmer tests, and osmolarity scores. Based on the evidence, omega-3 FAs effectively reduce DED symptoms, especially in high doses, for a long duration, and with increased EPA levels. However, given the heterogeneity in study results and diverse patient characteristics, caution is needed in generalizing these findings. In conclusion, omega-3 FA supplementation is still recommended for DED management in clinical settings.

Comparative study between triploid and diploid oysters (Crassostrea gigas) on non-volatile and volatile compounds

The quality of diploid oyster (crassostrea gigas) decreased significantly during the breeding period, which reflected the quality advantage of triploid oyster. However, there were few comparative studies on flavor quality characteristics between diploid and triploid oysters. This study compared the non-volatile compounds and volatile compounds between triploid and diploid oysters. These results showed that the percentage of eicosapentaenoic acid (EPA) in diploid oysters (18.68 ± 0.26%) was significantly higher than that in triploid oysters (16.16 ± 1.61%). The content of inosincacid (IMP) in diploid oysters (16.13 ± 0.03 mg/100 g) was significantly lower than that in triploid oysters (22.27 ± 0.41 mg/100 g). Adenosine monophosphate (AMP) content (364.08 ± 0.48 mg/100 g), succinic acid content (1244.51 ± 24.81 mg/100 g), and total free amino acid content (638.34 ± 17.32 mg/100 g) were significantly higher than those of triploid oysters (248.85 ± 2.32 mg/100 g, 420.99 ± 8.76 mg/100 g, 552.71 ± 17.32 mg/100 g, respectively). The main volatile compounds in diploid and triploid Pacific oysters were alcohols, aldehydes, ketones and esters. The volatile compounds content in triploid oysters were higher than those in diploid oysters. This study will provide basic data of Pacific oyster flavor and essential for the flavor pattern of seafood.

Characterization of the Positive Transcription Regulator PfaR for Improving Eicosapentaenoic Acid Production in Shewanella putrefaciens W3-18-1.

The biosynthetic pathway of eicosapentaenoic acid (EPA) has previously been reported in marine bacteria, while the regulatory mechanism remains poorly understood. In this study, a putative transcriptional regulator PfaR encoded adjacent to the PFA biosynthesis gene cluster (pfaEABCD) was computationally and experimentally characterized. Comparative analyses on the wild type (WT) strain, in-frame deletion, and overexpression mutants revealed that PfaR positively regulated EPA synthesis at low temperature. RNA-Seq and real-time quantitative PCR analyses demonstrated that PfaR stimulated the transcription of pfaABCD. The transcription start site of pfaR was mapped by using primer extension and highly conserved promoter motifs bound by the housekeeping Sigma 70 factor that were identified in the upstream of pfaR. Moreover, overexpression of PfaR in WT strain W3-18-1 at low temperature could improve EPA productivity from 0.07% to 0.13% (percentage of EPA to dry weight, mg/mg) of dry weight. Taken together, these findings could provide important implications into the transcriptional control and metabolic engineering in terms of EPA productivity for industrial strains. IMPORTANCE We have experimentally confirmed that PfaR is a positive transcription regulator that promotes EPA synthesis at low temperature in Shewanella putrefaciens W3-18-1. Overexpression of PfaR in WT strain W3-18-1 could lead to a 1.8-fold increase in EPA productivity at low temperature. It is further shown that PfaR may be regulated by housekeeping Sigma 70 factor at low temperature.

Omega-3 fatty acids in heart disease-why accurately measured levels matter.

Current guidelines barely support marine omega‑3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in cardiology, mainly because results of large trials were equivocal. Most large trials have tested EPA alone or EPA + DHA combined as adrug, thereby disregarding the relevance of their blood levels. These levels are frequently assessed with the Omega‑3 Index (percentage of EPA + DHA in erythrocytes), which is determined using aspecific standardised analytical procedure. EPA and DHA are present in every human being at unpredictable levels (even in the absence of intake), and their bioavailability is complex. Both facts need to be incorporated into trial design and should direct clinical use of EPA and DHA. An Omega‑3 Index in the target range of 8-11% is associated with lower total mortality, fewer major adverse cardiac and other cardiovascular events. Moreover, functions of organs such as the brain benefit from an Omega‑3 Index in the target range, while untoward effects, such as bleeding or atrial fibrillation, are minimised. In pertinent intervention trials, several organ functions were improved, with improvements correlating with the Omega‑3 Index. Thus, the Omega‑3 Index is relevant in trial design and clinical medicine, which calls for awidely available standardised analytical procedure and adiscussion on possible reimbursement of this test.

Growth, survival and fatty acid profile of hard clam, Mercenaria mercenaria, juveniles fed live microalgae diets

AbstractChoice of microalgae diet affects production outcomes in bivalve hatcheries. This study aimed to identify an optimal microalgae diet to improve hard clam, Mercenaria mercenaria, juvenile production. Four microalgae species (Tisochrysis lutea, Pavlova lutheri, Chaetoceros gracilis and Cyclotella nana) in six dietary combinations were fed for 6 weeks; then, growth, survival and fatty acid profiles of juveniles were evaluated. The highest numerical growth and survival of juveniles were attained by feeding a tetra‐species microalgae diet, but no statistical difference was found by feeding bi‐ or tri‐species diets that consisted of a mix of flagellate and diatom microalgae. Significant differences in fatty acid profiles were found among clams fed different microalgae diets. A contrasting polyunsaturated fatty acid (PUFA) profile was found in juveniles fed flagellate‐ or diatom‐only diets. Clams fed flagellate‐only diets contained a higher percentage of docosahexaenoic acid (DHA) but a lower percentage of (n‐6) PUFAs, whereas those fed diatom‐only diets had a higher percentage of arachidonic acid (ARA) and eicosapentaenoic acid (EPA) but a lower percentage of DHA. In contrast, the percentage of EPA, DHA and ARA was neither very high nor very low in juveniles fed the tetra‐species diet. The complementary nutritional profile of the tetra‐species microalgae diet resulted in enhanced production and exhibited a more balanced fatty acid profile in clam tissue. The tetra‐species microalgae diet should be a preferable choice for feeding hard clam juveniles, but the cost of producing multiple microalgae species for hatchery/nursery operations should be taken into consideration as bi‐ and tri‐species diets provided statistically similar growth and survival. Results of this study can be used to improve productivity and profitability in M. mercenaria hatcheries.

The effect of adding L-carnitine to omega-3 fatty acid diets on productive performance, oxidative stability, cholesterol content, and yolk fatty acid profiles in laying hens

In this study, different levels of Omega-3 fatty acids and L-carnitine (LC) were used in diets for laying hens. The effects of these supplements were examined on productive performance, antioxidant properties, cholesterol content, and yolk fatty acid profiles in the laying hens. A population of 120 Lohmann LSL-Lite laying hens (34-wk-old) were used in 2 × 3 factorial arrangements with 2 diets (control = 0.031 and 0.48% omega-3 fatty acids) and 3 levels of L-carnitine (0, 100, 200 mg/kg of diet) in a completely randomized design with 6 treatments. While having 5 replicates and 4 birds per replicate, the total period of the experiment lasted for 10 wk. The eggs were weighed daily, parallel to measurements of egg production, daily feed intake, feed conversion ratio, and egg mass. When the hens reached 44 wk of age, the measurements were aimed at fatty acid profiles, malondialdehyde (MDA), and cholesterol concentration in egg yolk. Feeding the hens on diets enriched by omega-3 fatty acids led to higher levels of egg production than those fed on control diets, but their daily feed intake was generally lower (P < 0.05). Egg weight decreased in birds that were fed on diets enriched with omega-3 fatty acids without L-carnitine, or with diets which contained 100 mg/kg L-carnitine, compared to control diets which contained 0 mg/kg L-carnitine (P < 0.05). Egg mass increased in birds that were fed on diets enriched with omega-3 fatty acids and which contained 200 mg/kg L-carnitine, compared to the control diet with 0 or 100 mg/kg L-carnitine (P < 0.05). The analysis of fatty acid profiles showed that L-carnitine and omega-3 fatty acids caused a significant increase in the percentage of eicosapentaenoic acid (EPA), docosahexaenoic  acid (DHA), C18: 1 (n-9), arachidonic acid (ARA) C20: 4 (n-6), and Σ n-3 in the eggs of birds (P < 0.05). Based on the results, adding L-carnitine (200 mg/kg) to diets that were already enriched with omega-3 fatty acids increased the level of production and led to a longer maintenance of fatty acids in the eggs. Also, oxidative stability was enhanced in the yolk of eggs.

Comparative Proteomics Reveals Evidence of Enhanced EPA Trafficking in a Mutant Strain of Nannochloropsis oculata.

The marine microalga Nannochloropsis oculata is a bioproducer of eicosapentaenoic acid (EPA), a fatty acid. EPA is incorporated into monogalactosyldiacylglycerol within N. oculata thylakoid membranes, and there is a biotechnological need to remodel EPA synthesis to maximize production and simplify downstream processing. In this study, random mutagenesis and chemical inhibitor-based selection method were devised to increase EPA production and accessibility for improved extraction. Ethyl methanesulfonate was used as the mutagen with selective pressure achieved by using two enzyme inhibitors of lipid metabolism: cerulenin and galvestine-1. Fatty acid methyl ester analysis of a selected fast-growing mutant strain had a higher percentage of EPA (37.5% of total fatty acids) than the wild-type strain (22.2% total fatty acids), with the highest EPA quantity recorded at 68.5 mg/g dry cell weight, while wild-type cells had 48.6 mg/g dry cell weight. Label-free quantitative proteomics for differential protein expression analysis revealed that the wild-type and mutant strains might have alternative channeling pathways for EPA synthesis. The mutant strain showed potentially improved photosynthetic efficiency, thus synthesizing a higher quantity of membrane lipids and EPA. The EPA synthesis pathways could also have deviated in the mutant, where fatty acid desaturase type 2 (13.7-fold upregulated) and lipid droplet surface protein (LDSP) (34.8-fold upregulated) were expressed significantly higher than in the wild-type strain. This study increases the understanding of EPA trafficking in N. oculata, leading to further strategies that can be implemented to enhance EPA synthesis in marine microalgae.

Application of genetic disruption of a Nannochloropsis oceanica cell wall synthesizing gene to n-3 HUFA enrichment of Brachionus plicatilis

It is believed that microalgae of the genus Nannochloropsis can replace fish oil as an n-3 highly unsaturated fatty acid (n-3 HUFA) source in live feed for sustainable marine fish larviculture. This is due to the fact that these microalgae are rich in eicosapentaenoic acid (EPA). On the other hand, the cell wall of microalgae is an obstacle to enriching live feed with n-3 HUFA. Manipulation of the cellulose synthase gene has the potential to facilitate degradation of the cell wall structure, although little is known how effective the genetically modified microalga would be in n-3 HUFA enrichment of live feed. This study aimed to evaluate the significance of the cellulose synthase gene-knockout strain (ΔCESA) of N. oceanica as an EPA enrichment diet for Brachionus plicatilis. The transgenic microalga was established via homologous recombination, and cultured under the same conditions as the wild-type strain (WT). According to the cellular ultrastructure, ΔCESA had a thinner cell wall than WT and its outer layer was unnaturally peeled back. Biochemical analysis revealed that with the exception of carbohydrates, WT and ΔCESA had comparable levels of proteins, lipids, and EPA. Carbohydrates were lower in ΔCESA than WT, which can cause changes in the cell wall structure. Digestive enzymatic and mechanical treatments of microalga showed ΔCESA to have higher accessibility of intracellular fatty acids. When microalga was used as the diet in the long-term cultivation of rotifers (1 week), rotifers fed ΔCESA presented higher growth rates than those fed WT. In short-term cultivation for rotifer EPA enrichment (≤24 h), the percentage of EPA in neutral lipids and phospholipids increased more rapidly in rotifers fed ΔCESA than those fed WT. As a result, rotifers fed ΔCESA for only 12 h exhibited comparable EPA levels to those fed WT for 24 h. The results of this study suggest that the efficiency of n-3 HUFA enrichment of rotifers is enhanced by feeding cellulose synthase gene-disrupted N. oceanica, due to the high vulnerability of its cell wall and unchanged nutritional value. Our findings provide evidence that gene modification technology can be applied to improve the targeted biological characteristics of microalgae used as the source of n-3 HUFA in marine larviculture.

Replacement of fishmeal by yellow mealworm meal on the growth performance, feed utilisation and quality of large yellow croaker

An 80-day feeding trial was conducted to evaluate the effects of yellow mealworm (Tenebrio molitor, TM) meal as substitute for dietary fishmeal on the growth performance, feed utilisation and flesh quality of large yellow croaker (initial body weight: 189.18±0.13 g). The control diet (TM0) was designed to contain 56% of fishmeal. Based on the TM0, graded levels of TM meal (15, 30, 45, 60, 75 and 100%, respectively) were used to replace fishmeal to formulate the other six experimental diets (TM15, TM30, TM45, TM60, TM75 and TM100), respectively. The results showed that the survival was not significantly affected by dietary TM meal levels (P&gt;0.05). Compared with control group, the final body weight, weight gain rate and protein efficiency ratio decreased significantly when the replacement level over 30%, while feed conversion ratio increased significantly as replacement level over 45% (P&lt;0.05). The total protein-bound amino acid content in muscle was significantly increased with the increase of dietary TM meal inclusion (P&lt;0.05). With replacement level increasing, the percentage of eicosapentaenoic acid (EPA) and Σn-3/Σn-6 poly-unsaturated fatty acids (PUFA) in muscle significantly decreased (P&lt;0.05). Meanwhile, the skin redness (a*) and yellowness (b*) values in the ventral and bottom of ventral regions showed a decreasing and increasing trend, respectively (P&lt;0.05). The TM100 group showed a higher myofibre diameter and lower myofibre density compared to the control group (P&lt;0.05). Total replacement of fishmeal with TM meal significantly down-regulated and up-regulated the expression of myf6 and mstn, respectively (P&lt;0.05). The contents of inosine-5′-monophosphate and total free amino acids were significantly decreased with the increase of TM meal inclusion (P&lt;0.05). In conclusion, TM meal can replace at least 30% of dietary fishmeal protein without negative effects on the growth, feed utilisation and flesh quality of large yellow croaker.

Effect of purification methods on functional properties of sardine oil ethyl esters

In this study, four methods including urea complexation (UC), molecular distillation (MD), low-temperature crystallization (LTC), and Ag+ bonded to mercaptopropyl silica gel column chromatography (AgMSG-CC) were adopted to purify eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from sardine oil ethyl esters (SOEEs). These methods were systematically compared in terms of physicochemical properties, fatty acid (FA) compositions, and volatile flavor compounds to evaluate the performance and find the superior among them. The AgMSG-CC method was superior in enhancing iodine value (IV) and reducing peroxide value (PV), enriching EPA and DHA from 31.63% to 92.19% and removing undesirable volatiles. Its mild experimental conditions could avoid the degradation and geometrical isomerization of lipids, and the packed AgMSG column could be reused. Multivariate data analysis was applied to provide an integrated and holistic view of correlation coefficients between the samples and FA species. The results supported the critical role of AgMSG-CC method in purifying EPA and DHA. Finally, this method was validated to be accurate and sensitive in the purification of EPA and DHA from SOEEs. Practical applications High quality of fish oil is related to its high content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and friendly aroma. However, enrichment methods about purifying fish oil affect the percentages of EPA and DHA, physicochemical indexes and the volatile flavor. In this study, the results demonstrated that Ag+ bonded to mercaptopropyl silica gel column chromatography was the most effective to purify EPA and DHA as well as remove the undesirable odor volatiles.

Palmitic acid and long-chain polyunsaturated fatty acids dominate in mycelia of mangrove Halophytophthora and Salispina species in Taiwan

Abstract Marine oomycetous species produce, among other fatty acids, omega-6 arachidonic acid (ARA) and omega-3 eicosapentaenoic acid (EPA), with implications for the industrial potential of this group of organisms and the need to find an isolate with high production. This study screened 14 isolates of marine oomycetous species: Halophytophthora avicenniae, H. batemanensis, H. exoprolifera, H. polymorphica and Salispina spinosa cultured from fallen mangrove leaves in Taiwan for 24 saturated and unsaturated fatty acids in their mycelia. This paper is the first to report C18:1n-7 vaccenic acid, C20:1 eicosenoic acid, C24:1 nervonic acid, C20:2n-6 eicosadienoic acid, C22:4n-6 adrenic acid, C20:4n-3 eicosatetraenoic acid and C22:5n-3 docosapentaenoic acid in mycelia of Halophytophthora and Salispina species, and the fatty acid profiles of H. batemanensis and H. exoprolifera. Five fatty acids were dominant in the mycelia of the isolates, i.e. C16:0 palmitic acid, C18:1n-9 oleic acid, C18:2n-6 linoleic acid, C20:4n-6 arachidonic acid and C20:5n-3 eicosapentaenoic acid. For the essential fatty acids, S. spinosa produced the highest level of arachidonic acid (27–31% of total fatty acid (TFA), 141–188 mg l−1 yield) while H. avicenniae IMB212 produced the highest percentage of EPA (15% of TFA) while H. polymorphica IMB227 produced the highest yield (96 mg l−1). Different species and isolates of the same species produced different fatty acid profiles, and further research effort may yield a high production isolate of industrial significance and also important fatty acids from the marine environment.

A comparative study of fatty acids profile of two Indian major carps (Gibelion catla, Hamilton, 1822 and Cirrhinus mrigala, Hamilton, 1822) using value added fish feed

Freshwater fishes are not only a major source of protein but they also possess nutritionally valuable lipids in the form of Polyunsaturated fatty acids (PUFAs), which play a crucial role in the normal growth, disease prevention, development, cardiovascular health and reproduction of human. The present study was performed to determine the incorporation rate of fatty acids profile and their composition in two common freshwater carps as Gibelion catla and Cirrhinus mrigala (in situ trial and experimental) in the different experimental time period (0 days, i.e. initial, 90 days and 180 days) by using of value added feed like flaxseed (?-linolenic acids, 51.26% – 54.94%) and soybean oil (?-linolenic acids, 7.95%-9.01%) as omega-3 supplements. To determine the specific growth pattern Length-Weight Relationships (LWRs) are analyzed where it showed positive allometric growth (b=3.20 in 90 days, b=3.11 in 180 days for Catla and b=3.18 in 90 days, b=3.1 in 180 days for Mrigala fish). The Gas Chromatography-Mass Spectrometry (GC/MS) method also confirmed that the percentages of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) increased significantly (P&lt; 0.05) in experimental (0.096a±0.41, initial; 5.16a±0.27, 90 days; 6.21b±0.36, 180 days Catla fish species and 0.019a±0.96 initial; 3.74b±0.37, 90 days; 3.50a±0.46 180 days for Mrigal fish species) fishes rather than controls (4.28a±0.27, 90 days; 4.36b±0.36, 180 days for Catla species and 2.24b±0.31 90 days; 2.50a±0.11 180 days for Mrigal species). Therefore, it was clearly indicated that formulated diet performed significantly to maintain the positive allometric growth as well as successive enrichment of PUFAs in experimental specimens, which is beneficial for human health as high source of protein and PUFAs as well.

The level of eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), in blood of Atlantic salmon (Salmo salar L.) is related to formulation and concentration of EPA or DHA in feed

The present study investigated how the concentration of PUFA in blood and muscle of Atlantic salmon (Salmo salar L.) changed when fed 4 diets containing very different amounts of LC-PUFA in fresh water for 84 days. The n-3 LC-PUFA constituted 4.4, 24.2, 18.4, and 51.5% of the total fatty acids in the diets made with rapeseed oil, anchoveta oil, a combination of rapeseed oil (60%) and anchoveta oil (40%), and EPA/DHA concentrate, respectively. No significant differences in the growth were observed in the groups during the feeding experiment. The changes in n-3 LC-PUFA in blood and muscle were however quite different in the 4 feeding groups. In the blood, DHA was mobilised to or retained at high level (30–36%) even with a very low amount of DHA in the feed. The concentration of EPA in the blood reflected to a large degree the concentration in the feed, with a rapid increase of EPA in the blood during the first 21 days of feeding. The level of EPA in the blood remained at this level for the rest of the study. However, when only small amounts (1.8%) were present in the feed the fatty acid appeared to be selectively mobilised to or retained in the blood. In the muscle, the percentage of EPA, DHA and other fatty acids mirrored the amounts in the feed suggesting increased TAG (triacylglycerides) during the feeding period.

Early-onset coronary atherosclerosis in patients with low levels of omega-3 fatty acids.

Coronary artery calcification (CAC) can reliably predict cardiovascular events. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are thought to inhibit vascular calcification on a cellular level and in animal models, however, the correlation in humans is controversial. In symptomatic patients, CAC was quantified according to Agatstons' method using non-contrast coronary CT. We assessed the association of EPA and DHA with early-onset coronary atherosclerosis, defined as presence of CAC above the 75th Agatston-Score (AS) percentile in sex adjusted age categories. Erythrocyte fatty acid composition was analyzed with a standardized methodology. The percentage of EPA and DHA in relation to all fatty acids present in the erythrocyte membrane is regarded the Omega-3 Index®. Among 71 patients, 51 were below and 20 were above the 75th AS-percentile. No differences were seen in age, gender, cardiovascular risk factors, and relevant medication. In univariable analysis, significantly lower values for EPA (0.77%[0.63; 0.97] vs. 0.93%[0.72; 1.21]; p = 0.045), DHA (4.90%[4.12; 5.57] vs. 5.50%[4.58; 6.52]; p = 0.038) and the Omega-3 Index (5.73%[4.75; 6.35] vs. 6.22%[5.46; 7.71]; p = 0.034) were seen in patients above the 75th AS-percentile. All other fatty acids showed no significant differences. In multivariable analysis, the Omega-3 Index showed a significant inverse association with early onset of CAC (OR: 0.533 (95%CI: 0.303-0.938; p = 0.029)), independent of age, gender, statin use, and creatinine level (all p > 0.05). Low levels of EPA and DHA (Omega-3 Index) are associated with early-onset coronary atherosclerosis. This finding needs to be validated in larger cohorts and might help understand the beneficial cardiovascular effects of omega-3 fatty acids.

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

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.

Evaluation of macroalgal detritus as food source for juvenile Manila clam, Ruditapes philippinarum : Effects on growth, amino acid content and fatty acid composition

Sufficient high-quality microalgae are required for indoor nursery of juvenile Ruditapes philippinarum. However, culturing numerous microalgae to support clam feeding is a heavy burden on many hatcheries. The effects of detritus from the macroalgae Ulva pertusa, Chondrus ocellatus and Undaria pinnatifida on the growth, amino acid content and fatty acid profile of R. philippinarum were assessed as potential substitute diets. The green microalga Tetraselmis cordiformis served as comparative diet. Results revealed that the clams ingesting distinct diets presented no significant differences in growth of soft tissues, but the nutritional component of these clams differed dramatically. The clams fed with Undaria + Tetraselmis had the highest content of essential amino acids and proteins. In addition, the clams fed with single macroalgal diets and mixed macroalgal detritus and Tetraselmis showed significantly higher or statistically equal levels in n-3/n-6 ratio and docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) ratio with respect to Tetraselmis diets. The relative percentages of EPA and DHA in clams fed with Undaria were 28% and 63% higher than those fed with Tetraselmis, and the arachidonic acid abundances in clams ingesting Undaria + Tetraselmis and Tetraselmis were significantly higher than those in clams ingesting other diets. Together, the diets containing single Undaria or mixed Undaria + Tetraselmis produced Manila clams with nutritional advantages in terms of essential amino acids and polyunsaturated fatty acids. Thus, the detritus of macroalgae, especially Undaria, is an appropriate substitute diet, at least partially, for culture of nutrition-improved R. philippinarum.

The Association of Polyunsaturated Fatty Acid δ-5-Desaturase Activity with Risk Factors for Type 2 Diabetes Is Dependent on Plasma ApoB-Lipoproteins in Overweight and Obese Adults

δ-5 and δ-6 desaturases (D5D and D6D) catalyze the endogenous conversion of n-3 (ω-3) and n-6 (ω-6) polyunsaturated fatty acids (PUFAs). Their activities are negatively and positively associated with type 2 diabetes (T2D), respectively, by unclear mechanisms. Elevated plasma apoB-lipoproteins (measured as plasma apoB), which can be reduced by n-3 PUFA intake, promote T2D risk factors. The aim of this study was to test the hypothesis that the association of D5D and D6D activities with T2D risk factors is dependent on plasma apoB. This is a pooled analysis of 2 populations recruited for 2 different metabolic studies. It is a post hoc analysis of baseline data of these subjects [n=98; 60% women (postmenopausal); mean ± SD body mass index (in kg/m2): 32.8±4.7; mean ± SD age: 57.6±6.3 y]. Glucose-induced insulin secretion (GIIS) and insulin sensitivity (IS) were measured using Botnia clamps. Plasma clearance of a high-fat meal (600 kcal/m2, 66% fat) and white adipose tissue (WAT) function (storage of 3H-triolein-labeled substrate) were assessed in a subpopulation (n=47). Desaturase activities were estimated from plasma phospholipid fatty acids. Associations were examined using Pearson and partial correlations. While both desaturase activities were positively associated with percentage of eicosapentaenoic acid, only D5D was negatively associated with plasma apoB (r=-0.30, P=0.003). Association of D5D activity with second-phase GIIS (r=-0.23, P=0.029), IS (r=0.33, P=0.015, in women) and 6-h area-under-the-curve (AUC6h) of plasma chylomicrons (apoB48, r=-0.47, P=0.020, in women) was independent of age and adiposity, but was eliminated after adjustment for plasma apoB. D6D activity was associated in the opposite direction with GIIS (r=0.24, P=0.049), IS (r=-0.36, P=0.004) and AUC6h chylomicrons (r=0.52, P=0.004), independent of plasma apoB. Both desaturases were associated with plasma interleukin-1-receptor antagonist (D5D: r=-0.45, P<0.001 in women; D6D: r=-0.33, P=0.007) and WAT function (trend for D5D: r=0.30, P=0.05; D6D: r=0.39, P=0.027) independent of any adjustment. Association of D5D activity with IS, lower GIIS, and plasma chylomicron clearance is dependent on plasma apoB in overweight and obese adults.

Development of fed batch strategies to improve the production of eicosapentaenoic acid from a marine microalga Nannochloropsis oculata

Marine microalgae are emerging as a source of polyunsaturated fatty acids and other commercially important nutraceuticals and pharmaceuticals. In this work, batch and fed batch modes were assessed to improve the performance of Nannochloropsis oculata as an eicosapentaenoic acid (EPA) producer. Fed batch strategies devised in this study involve simultaneous C and nitrogen (N) supplementation resulting in promising boost in biomass and EPA productivities. Individually, mixotrophic C supplementation improved the biomass productivity (0.17 g·L−1·d−1) and total lipid content (~72.69% dry cell weight) while N supplementation led to higher EPA percentage (33.9%) on overall fatty acid profile. This study is the first to explore molasses, a carbon (C) rich industrial effluent, as an alternative C source for mixotrophic growth of N. oculata. Collectively, this study explores potential growth regimes to enhance feasibility of biomass production without compromise in EPA productivity in N. oculata.

Production of eicosapentaenoic acid by application of a delta-6 desaturase with the highest ALA catalytic activity in algae

Dunaliella salina is a unicellular green alga with a high α-linolenic acid (ALA) level, but a low eicosapentaenoic acid (EPA) level. In a previous analysis of the catalytic activity of delta 6 fatty acid desaturase (FADS6) from various species, FADS6 from Thalassiosira pseudonana (TpFADS6), a marine diatom, showed the highest catalytic activity for ALA. In this study, to enhance EPA production in D. salina, FADS6 from D. salina (DsFADS6) was identified, and substrate specificities for DsFADS6 and TpFADS6 were characterized. Furthermore, a plasmid harboring the TpFADS6 gene was constructed and overexpressed in D. salina. Our results revealed that EPA production reached 21.3 ± 1.5 mg/L in D. salina transformants. To further increase EPA production, myoinositol (MI) was used as a growth-promoting agent; it increased the dry cell weight of D. salina transformants, and EPA production reached 91.3 ± 11.6 mg/L. The combination of 12% CO2 aeration with glucose/KNO3 in the medium improved EPA production to 192.9 ± 25.7 mg/L in the Ds-TpFADS6 transformant. We confirmed that the increase in ALA was optimal at 8 °C; the EPA percentage reached 41.12 ± 4.78%. The EPA yield was further increased to 554.3 ± 95.6 mg/L by supplementation with 4 g/L perilla seed meal (PeSM), 500 mg/L MI, and 12% CO2 aeration with glucose/KNO3 at varying temperatures. EPA production and the percentage of EPA in D. salina were 343.8-fold and 25-fold higher than those in wild-type D. salina, respectively.ImportanceFADS6 from Thalassiosira pseudonana, which demonstrates high catalytic activity toward α-linolenic acid, was used to enhance EPA production by Dunaliella salina. Transformation of FADS6 from Thalassiosira pseudonana into Dunaliella salina with myoinositol, CO2, low temperatures, and perilla seed meal supplementation substantially increased EPA production in Dunaliella salina to 554.3 ± 95.6 mg/L. Accordingly, D. salina could be a potential alternative source of EPA and is suitable for its large-scale production.