Total Lipid Fatty Acid Research Articles

Lipid Fatty Acids from the Pericarp of Cydonia oblonga Mill. and Mespilus germanica L. are Involved in Plant Adaptation to Altitudinal Zonality.

The composition of fatty acids of total lipids of the outer and parenchymal parts of the pericarp in Cydonia oblonga Mill. and Mespilus germanica L. (Maloideae, Rosaceae), growing in the Northern Caucasian mountains at altitudes of 300, 500, 700, and 1200m above sea level in various natural zones from experimental sites, was studied for the first time. It is established that the altitude of plant growth is largely correlated with the changes in the FA composition of the outer, but not the parenchymal, part of the pericarp. The nature of this variability suggests that the adaptation of plants to the conditions of significant temperature differences in the mountains is associated with the regulation of cell membrane fluidity, based on the interaction of opposite processes of synthesis of polyunsaturated and very-long-chain fatty acids.

Impacts of a Balanced Omega 6:3 Diet on Fatty Acid Deposition in White and Brown Adipose Tissue and Circulating Plasma in the Hibernating Arctic Ground Squirrel

Hibernators, such as arctic ground squirrels (AGS), fuel the majority of all their metabolic needs from fat deposits through the hibernation season (Dark 2005). Natural fatty acid profiles of free‐ranging AGS have omega 6:3 ratios close to 1:1, showing a far higher consumption of omega 3 fatty acids than captive animals, fed a standard Mazuri rodent chow (which have omega 6:3 ratios close to 8:1). Specific concentrations of omega 6 polyunsaturated fatty acids (PUFAs) enhance hibernation (Frank 2008) and absence of essential fatty acids reduce time in torpor (Florant 1993). To our knowledge, only three studies have investigated the impact of omega 3s on hibernation physiology (Giroud 2018, Frank 2004, and Hill and Florant 2000). In other species, high consumption of omega 3 fatty acids show dose‐dependent lowering of serum triglycerides with other health benefits (Balk 2006). How increased consumption of omega 3 fatty acids impact brown adipose tissue deposition and fatty acid profiles in tissue and serum related to storage and utilization in hibernating AGS is unknown.A group of wild juvenile AGS (female=12, male=12) were fed either a test diet, with an omega 6:3 ratio of 1.3:1, or a standard chow control diet, with an omega 6:3 ratio of 8:1, from mid‐July (after trapping and quarantine) till animals entered hibernation (August–September). Tissues were collected mid‐December at three specific physiological states of hibernation: early torpor, late torpor and arousal. Total lipid fatty acid profiles of plasma, brown adipose and white adipose tissue were quantified by GC analysis. Axillar brown adipose tissue was dissected and weighed.Preliminary results show a significant increase in axillar brown adipose tissue mass in the omega 6:3 balanced diet animals (p<0.038). Preliminary data also indicates increased percentages of circulating levels of polyunsaturated fatty acids in plasma of hibernating AGS compared to summer or fall animals (p<0.01). Full fatty acid analysis is pending.In conclusion, our preliminary results indicate a balanced diet of omega 6:3 (1:3:1) in hibernating Arctic Ground Squirrels may enhance brown adipose tissue deposition.Support or Funding InformationThis work was supported by NIH 20GM103395, UL1GM118991, TL4GM118992, or RL5GM118990. This work was performed in conformance with the FASEB Statement of Principles for animals used in research.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Content and Composition of Fatty Acids in Total Lipids from the Buds of Betula pubescens, B. pendula, and B. pendula var. carelica

Absolute content and composition of fatty acids (FAs) in total lipids from the buds of white birch (Betula pubescens Ehrh.), silver birch (B. pendula Roth), and its subspecies B. pendula var. carelica Merckl. were investigated. The examined birches differed in these characteristics calculated per gram of dry weight. The buds of Karelian birch contained reliably greater content of FAs in total lipids as compared with the buds of two other birches. Detected differences in the content of total lipid FAs in two species and one variety of birch reflect peculiarities of biosynthesis of lipid compounds and may serve as an indicator for identification of plants from the genus Betula L.

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Multitrophic interactions in the rhizosphere of a temperate forest tree affect plant carbon flow into the belowground food web

Tree roots and mycorrhizal fungi form an important resource for soil microinvertebrates; however, there is little knowledge on the role of root feeders and microbial grazers on belowground carbon flux of forest trees. Using oak (Quercus robur) microcuttings (Clone DF159) inoculated with an ectomycorrhizal symbiont partner (Piloderma croceum), the present study investigated the impact of multitrophic interactions in the rhizosphere on the carbon flow to the soil food web in a pulse-chase labelling experiment. Changes in plant biomass, microbial communities (soil phospholipid fatty acids - PLFAs) and Collembola lipid pattern (total lipid fatty acids - TLFAs) as well as the 13C incorporation into fatty acids were assessed at 2, 5 and 20 days post labelling of oak microcuttings. Microcosms were inoculated with Pratylenchus penetrans (root-feeding nematode), Protaphorura armata (fungal-feeding Collembola) or their combination. The interaction of P. penetrans and P. armata synergistically reduced oak biomass. Both soil animals independently impacted growth of microorganisms in the rhizosphere, P. penetrans inhibited whilst P. armata promoted bacterial biomass. Irrespective of treatment and time, Gram-positive bacteria derived most of the recent photoassimilated oak carbon, with amounts ranging between 80 and 92% of the total 13C allocated in microbial PLFAs. Presence of either P. armata or P. penetrans enhanced the incorporation of plant carbon in bacteria, whereas collective effects of these two functional groups was scarce. Predominantly the impact of the root-feeding nematode on belowground carbon flow diminished with time. In sum, root feeders and detritivores played independent roles in carbon allocation patterns and community structure of microorganisms in the rhizosphere of oaks.

Fatty acid and lipid profiles in primary human trophoblast over 90 h in culture

Little is known about the mechanisms underlying the preferential transport of long chain polyunsaturated fatty acids (LCPUFA) to the fetus by the syncytiotrophoblast and the role of cytotrophoblasts in placental lipid metabolism and transport. We studied primary human trophoblast (PHT) cells cultured for 90h to determine the fatty acid and lipid composition of cytotrophoblast (18h culture) and syncytiotrophoblast (90h culture) cells. In cultured PHT total lipid fatty acids were significantly (P < 0.05) reduced at 90h compared to 18h in culture including lower levels of palmitic acid (PA, 16:0, −37%), palmitoleic acid (POA, 16:1n-7, −30%), oleic acid (OA, 18:1n-9, −31%), LCPUFA arachidonic acid (AA, 20:4n-6, −28%) and α-linolenic acid (ALA, 18:3n-3, −55%). In major lipid classes, OA and most of the n-3 and n-6 LCPUFA were markedly lower at 90h in TG (−57 to −76%; p < 0.05). In the cellular NEFA, n-6 LCPUFA, dihomo-γ-linolenic acid (DGLA, 20:3n-6) and AA were both reduced by −51% and DHA was −55% lower (p < 0.05) at 90h. In contrast, phospholipid FA content did not change between cytotrophoblasts and syncytiotrophoblast except for OA, which decreased by −62% (p < 0.05). Decreasing PHT TG and NEFA lipid content at 90h in culture is likely due to processes related to differentiation such as alterations in lipase activity that occur as cytotrophoblast cells differentiate. We speculate that syncytiotrophoblast prioritizes PL containing AA and DHA for transfer to the fetus by mobilizing FA from storage lipids.

The content of fat acids of general lipids and heavy metals in pollen from dande-lion under different technogenic impact on environment

The level of environmental impact was determined by the content of heavy metals (iron, zinc, copper, chromium, nickel, lead, arsenic and cadmium) in the pollen from dandelion (TaraxacumofficinaleWigg.). Samples of pollen from dandelion for laboratory tests were taken in apiaries located in areas with different intensity of traffic and industry. In particular, the training apiary of Lviv National University of Veterinary Medicine and Biotechnologies named after S.Z. Gzhytsky (the area with very heavy traffic and operation of industrial enterprises) and private beekeeping farms in Vynnyky town and Chyzhykiv village in Pustomiti district Lviv region (areas with less intensity of traffic and industry). Private beekeeping farms in Vynnyky town and Chyzhykiv village are located at a distance of 2–3 and 5–6 km from the training apiary of Lviv National University of Veterinary Medicine and Biotechnologies named after S.Z. Gzhytsky. Moreover, both the training apiary of Lviv National University of Veterinary Medicine and Biotechnologies named after S.Z. Gzhytsky and private beekeeping farms in Vynnyky and Chyzhykiv of Pustomiti district Lviv Oblast are located along the highway Lviv–Ternopil. In each of the mentioned above areas samples of the pollen of dandelion. And in each apiary the samples of the pollen of dandelion and newly built honeycombs were taken from three hives. To clarify the origin of species of the dandelion pollen the identification study was performed using the computer programs «LUCIA» (Laboratory Colour Image Analysis) and «Pollen Data Bank». In the selected samples of the bee pollen heavy metals were found and measured. In the selected samples of newly built honeycombs the concentration of heavy metals, anionic and nonetherified fatty acids and fatty acids of total lipids was measured. The content of heavy metals in the studied biological material was measured on atomic absorption spectrophotometer C–115 PC. The concentration of anionic and nonetherified fatty acids and fatty acids of total lipids in the studied biological material were measured by the gas–liquid chromatography. The resulting digital material was studied and analyzed by variation statistics using the Student's criterion. The arithmetic mean value and arithmetic errors were calculated. Changes were considered probable at p &lt;0.05. For calculations a special computer program Origin 6.0, Excel (Microsoft, USA) was used. The pollen of the dandelion which grows in the area with medium and low technogenic load in comparison with the pollen of the dandelion which grows in the area with high technogenic load the amount of iron, zinc, copper, chromium, nickel, lead and cadmium decreases. The pollen of the dandelion which grows in the area with medium and low technogenic load in comparison with the pollen of the dandelion which grows in the area with high technogenic load the amount of fatty acids of common lipids increases mainly due to monounsaturated fatty acids of n–7 and n–9 families and polyunsaturated fatty acids of n–3 and n–6 families. Therefore their energetic, attractive, functional–metabolic and biologic value for the bee organism increases. The most considerable change in the amount of heavy metals and fatty acids of common lipids is observed in the pollen of the dandelion which grows in the area of low technogenic load.

Lipid composition in muscle and liver of sympatric coregonid fishes from Lake Baikal (Coregonus spp.) under common garden experiment

The content of total lipids, total phospholipids, and fatty acids of total lipids in muscles and liver of juvenile Lake Baikal sympatric coregonid fishes have been analyzed for the first time under a common garden experiment. Baikal omul, Coregonus migratorius Georgi, is an active migrant of the pelagic zones of the lake. Baikal (lacustrine) whitefish, C. baicalensis Dybowski, is a colonizer of the bottom habitats, which are relevant to the pelagic zones of the littoral and underwater slope. Structural lipids (phospholipids and cholesterol) dominated in total lipids of the tissues of all fish under study. Spare lipids significantly prevailed in omul muscles when compared to whitefish. The highest variability of fatty acid composition was reported in muscles of coregonid fishes. Statistically significant differences were revealed in the content of the ω3 polyunsaturated fatty acids in muscles of lacustrine whitefish and omul. Associations of lipid compositions revealed in tissues of the whitefishes under the study with their respective ecotypes have been discussed.

Exploring occurrence and molecular diversity of betaine lipids across taxonomy of marine microalgae

Betaine lipids (BL) from ten microalgae species of the kingdoms Plantae and Chromista were identified and quantified by HPLC/ESI-TOF-MS. Diacylgyceryl-N-trimethylhomoserine (DGTS) was detected in Trebouxiophyceae and Eustigmatophyceae species, whereas Tetraselmis suecica was described as the first green algae containing diacylglyceryl-hydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA). DGTA molecular species where also characterized in Cryptophyceae species as well as in the Bacillariophyceae diatom Phaeodactylum tricornutum. The Mediophyceae diatom Chaetoceros gracilis had no DGTA, but contained diacylglyceryl-carboxyhydroxymethylcholine (DGCC). A principal coordinate (PCO) analysis of microalgae species revealed the existence of three main clusters around each BL type. The first PCO axis (43.9% of total variation) grouped Chlorophyceae, Trebouxiophyceae and Eustigmatophyceae species and positively correlated with DGTS. The second PCO axis (27.8% of total variation) segregated DGTA from DGCC containing species. Cryptophyceae, Bacillariophyceae and Chlorodendrophyceae were the more closely associated species to DGTA. Mediophyceae and Dinophyceae species contained DGCC as the only BL. Molecular diversity varied from the simplest DGCC composition in Gyrodinium dorsum to the highest spectrum of ten different molecular species detected for DGTA (Rhodomonas baltica) and DGCC (C. gracilis). The fatty acid profile of DGTS was very dissimilar to that of the whole lipid cell content. DGTS from Nannochloropsis gaditana was highly unsaturated respecting to total lipids, whereas in Picochlorum atomus DGTS unsaturation was nearly one half to that of total lipids. Dissimilarity between DGTA and total lipid fatty acid profile was minimum among all BL and DGTA fatty acid unsaturation was the maximum observed in the study. New DGCC molecular species enriched in 20:5 were described in Mediophyceae diatoms. Multivariate microalgae ordination using BL as descriptors revealed a higher chemotaxonomic potential than that based on their respective BL fatty acid profile. Nevertheless, taxonomic resolution was improved when fatty acids from the whole cell lipid pool were used.

Placental MFSD2a transporter is related to decreased DHA in cord blood of women with treated gestational diabetes

Maternal-fetal transfer of docosahexaenoic acid (DHA) is impaired by gestational diabetes mellitus (GDM), but the underlying mechanisms are still unknown. MFSD2a was recently recognized as a lyso-phospholipid (lyso-PL) transporter that facilitates DHA accretion in brain. The role of this transporter in placenta is uncertain. We evaluated effects of GDM and its treatment (diet or insulin) on phospholipid species, fatty acid profile in women, cord blood and placental fatty acid carriers. Prospective observational study of pregnant women recruited in the third trimester (25 controls, 23 GDM-diet, 20 GDM-insulin). Fetal ultrasound was performed at gestational week 38. At delivery, maternal and neonatal anthropometry was performed, and fatty acids in total lipids and phospholipid species were analyzed in placenta, maternal and venous cord blood. Western-blot analyses were performed for placental fatty acid carriers. Fetal abdominal circumference z-score at 38 weeks tended to higher values in GDM (P=0.071), pointing toward higher fetal fat accretion in these babies. DHA percentage in cord serum total lipids (P=0.029) and lyso-PL (P=0.169) were reduced in GDM. Placental MFSD2a was reduced in both GDM groups and was positively correlated to DHA values in cord serum total lipids (r=0.388, P=0.003). Among established placental lipid carriers, only FATP4 was correlated to DHA concentration in placental lyso-PL. In all compartments, DHA percentage was inversely correlated to fetal abdominal circumference. In offspring of women with GDM treated either with diet or insulin, higher fetal fat accretion and lower placental MFSD2a contribute to reduce DHA availability. Lyso-PL appear to contribute to materno-fetal DHA transport.

Characterisation of commercial Perna canaliculus samples and development of extemporaneous oral veterinary paste formulations containing Perna

Perna canaliculus is a nutritional supplement recently studied and highly recommended for its anti-inflammatory effects in both animals and humans. In this study, the physicochemical properties, the microbiological quality, the total lipid content and fatty acids composition of three commercial samples of Perna powder were determined. Subsequently, three simple formulations of extemporaneous oral pastes containing Perna were prepared and designed for veterinary use. Their microbiological stability was assessed after 1-month storage at either room temperature or 35 °C. The results demonstrated that commercial Perna samples lack homogeneity, in regard to some technological properties and fatty acid composition; therefore, a preliminary characterisation of commercial Perna samples is recommended to assure the quality of formulations containing this nutritional supplement. Oral paste formulations are easy and simple to prepare and show good physical and microbiological stability, suggesting their large-scale production.

Polyunsaturated molecular species of galactolipids: Markers of zooxanthellae in a symbiotic association of the soft coral Capnella sp. (Anthozoa: Alcyonacea)

A method that uses marker fatty acids (FAs) is widely applied in investigations of trophic and symbiotic relationships. In a search for new lipid markers, we determined the total lipid FA composition, as well as the composition of molecular species of mono- and digalactosyl diacylglycerols (MGDGs and DGDGs), which are specific galactolipids of thylakoid membranes, in zooxanthellae (endosymbiotic dinoflagellates) of the tropical soft coral Capnella sp. Some FAs of zooxanthellae were suggested for use as marker polyunsaturated FAs (PUFAs). Thirteen molecular species of MGDGs and ten molecular species of DGDGs were detected using the method of high-resolution tandem mass spectrometry. All marker PUFAs of zooxanthellae were found in acyl groups of galactolipids. The major molecular species of DGDGs (18:4/18:4, 18:4/20:5, and 16:2/22:6) and the unique molecular species of MGDGs (16:4/18:5) were described. The identification of several polyunsaturated molecular species of galactolipids that contain marker FAs allowed us to propose that this lipid group be used as molecular lipid markers of zooxanthellae for the study of symbiont–host interactions in soft corals.

Hempseed Products Fed to Hens Effectively Increased n-3 Polyunsaturated Fatty Acids in Total Lipids, Triacylglycerol and Phospholipid of Egg Yolk.

Hempseed products represent potential alternative feed ingredients for poultry. However, their usage is not currently approved due to a lack of data to support their safety and efficacy. In this regard, the current study was conducted to assess the impact of dietary concentration of hempseed (HS) products and duration of their feeding to hens on the polyunsaturated fatty acid (PUFA) composition of egg yolk lipids. In the current study, 48 Lohmann LSL-Classic hens were individually housed in metabolism cages, in a completely randomized design, and provided one of six diets (wheat-barley-soybean-based) containing either HS (10, 20 and 30%), hempseed oil (HO; 4.5 and 9.0%) or no hempseed product (control) over 12weeks. Increasing alpha-linolenic acid (ALA) intake via increasing dietary hempseed product inclusion, significantly (p<0.0001) increased the n-3 PUFA contents of yolk total lipid. The values of ALA increased by 12-fold (152±3.56 and 156±2.42mg/yolk) and docosahexaenoic acid (DHA) by twofold to threefold (41.3±1.57 and 43.6±1.61mg/yolk) over the control, for the highest levels of HS and HO inclusion, respectively. Increasing levels of hemp products in laying hen diets proved effective in manipulating the fatty acid profile of the total lipid, triacylglycerol (TAG) and total phospholipid (PL) fractions of yolks, enhancing the n-3 fatty acids and reducing the n-6/n-3 ratio. The latter benefit was achieved within 4weeks of feeding hens either HS- or HO-containing diets.

Evaluation of the effect of dietary sesamin on white muscle lipid composition of common carp (Cyprinus carpioL.) juveniles

This study was focused on the clarification of the effect of dietary sesamin on fatty acids and the composition of different lipid fractions [phospholipids (PLs), cholesterol and triacylglycerols] in the white muscle of common carp (Cyprinus carpio L.) juveniles. Two different basic diets with defatted fishmeal as a protein source and either only linseed oil or a mixture of linseed and sunflower oil as a lipid source designed to have two different n-3/n-6 ratios (1.21 – CL group; 0.32 – CM group) were produced. Each diet was then used with or without added sesamin (0.58 g 100g−1). One hundred and forty-four individuals were fed in triplicated groups for 63 days until their weight had doubled. No influence of dietary sesamin on growth, mortality or on the white muscle lipid content of the fish was found. Added sesamin significantly decreased the content of PLs and increased the cholesterol content in the CM group. No effect was found in the total lipid fatty acid composition but there was found a significantly lower content of saturated fatty acids and 20:5n-3 in PLs and of 22:6n-3 in triacylglycerols in the sesamin supplemented CL group. These and other differences show either a tendency of lower long chain n-3 fatty acids biosynthesis or their higher use in β-oxidation in sesamin-supplemented groups. We conclude that sesamin in this experiment had no substantial positive impact on the lipid metabolism of juvenile carp.

Жирные кислоты общих липидов видов рода Cystoseira C. Agardh (Phaeophyta) (Черное море, Крым)

Жирные кислоты общих липидов видов рода Cystoseira C. Agardh (Phaeophyta) (Черное море, Крым)

Distribution of omega-6 and omega-3 polyunsaturated fatty acids in the whole rat body and 25 compartments

The steady state compositions of omega-6 and omega-3 polyunsaturated fatty acids (PUFA) throughout the various viscera and tissues within the whole body of rats have not previously been described in a comprehensive manner. Dams consumed diets containing 10wt% fat (15% linoleate and 3% α-linolenate). Male offspring (n=9) at 7-week of age were euthanized and dissected into 25 compartments. Total lipid fatty acids for each compartment were quantified by GC/FID and summed for the rat whole body; total n−6 PUFA was 12wt% and total n−3 PUFA was 2.1% of total fatty acids. 18:2n−6 accounted for 84% of the total n−6 PUFA, 20:4n−6 was 12%, 18:3n−3 was 59% of the total n−3 PUFA, 20:5n−3 was 2.1%, and 22:6n−3 was 32%. The white adipose tissue contained the greatest amounts of 18:2n−6 (1.5g) and 18:3n−3 (0.2g). 20:4n−6 was highest in muscle (60mg) and liver (57mg), while 22:6n−3 was greatest in muscle (46mg), followed by liver (27mg) and carcass (20mg). In terms of fatty acid composition expressed as a percentage, 18:2n−6 was the highest in the heart (13wt%), while 18:3n−3 was about 1.3wt% for skin, white adipose tissue and fur. 20:4n−6 was highest (21–25wt%) in the circulation, kidney, and spleen, while 22:6n−3 was highest in the brain (12wt%), followed by the heart (7.9wt%), liver (5.9wt%), and spinal cord (5.1wt%). Selectivity was greatest when comparing 22:6n−3 in brain (12%) to white adipose (0.08%) (68-fold) and 22:5n−6 in testes (15.6%) compared to white adipose (0.02%), 780-fold.

Detailed Study of Furan Fatty Acids in Total Lipids and the Cholesteryl Ester Fraction of Fish Liver

Furan fatty acids (F-acids) are valuable, bioactive minor components in lipids which are characterized by a furan moiety in the acyl chain. Here, we present a gas chromatography/mass spectrometry method operated in the selected ion monitoring mode (GC/MS-SIM) for the thorough determination of F-acid as methyl esters in fish. The method takes advantage of the molecular ion and two characteristic fragment ions and enables the unequivocal detection of >350 saturated, mono- and dienoic F-acids in four GC/MS-SIM runs. This method was applied to the analysis of the methyl esters obtained from the triacylglyceride (TG) and the cholesteryl ester (CE) fraction of ten individual fish liver samples. Up to 23 F-acids, including several new or scarcely detected homologues, were detected in the samples. The concentrations of total F-acids ranged from 25 to 280 mg/100 g lipids in the TG fractions and <0.11 to 115 mg/100 g lipids in the CE fractions.

Microalgae lipid characterization.

To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco- and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization.

FemaleLeuciscus lepidusMay Be a New Alternative for Fish Oil Supplements

The proximate composition of male and femaleLeuciscus lepidusin Beyşehir Lake was investigated. The fatty acid profiles of total lipid, phospholipid, and triacylglycerol in muscle and liver of male and femaleL. lepiduswere evaluated by gas chromatography. Proximate analyses showed that meat of male and femaleL. lepidushad 15.13 ± 0.04 and 18.75 ± 0.11% fat, 20.42 ± 0.45 and 22.21 ± 0.56% protein, 65.47 ± 1.37 and 61.28 ± 1.03% moisture, and 1.51 ± 0.05 and 1.50 ± 0.03% ash, respectively. The percentage of total saturated fatty acids was higher in liver than in muscle, whereas the total polyunsaturated fatty acid (PUFA) content was the lowest in all fatty acid profiles. The phospholipids contained more PUFAs than triacylglycerol. Analysis of variance indicated significant differences (P&lt;0.05) between male (47.51%) and female (49.98%) muscle PUFAs in total lipid. The proportion of omega 3 (ω3) to omega 6 (ω6) fatty acids of total lipid was 3.15 in male and 3.68 in female. The ratio is an important indicator for comparing the value of fish oil. Therefore, it was concluded thatL. lepiduswas considered to be a high quality product for healthy food choice. Additionally, femaleL. lepidusmay especially be used to produce fish oil supplements from freshwater fish combined with vegetable oils.

Engineering increased triacylglycerol accumulation in Saccharomyces cerevisiae using a modified type 1 plant diacylglycerol acyltransferase.

Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1,2-diacylglycerol to produce triacylglycerol (TAG). This enzyme, which is critical to numerous facets of oilseed development, has been highlighted as a genetic engineering target to increase storage lipid production in microorganisms designed for biofuel applications. Here, four transcriptionally active DGAT1 genes were identified and characterized from theoil crop Brassica napus. Overexpression of each BnaDGAT1 in Saccharomyces cerevisiae increased TAG biosynthesis. Further studies showed that adding an N-terminal tag could mask the deleterious influence of the DGATs' native N-terminal sequences, resulting in increased in vivo accumulation of the polypeptides and an increase of up to about 150-fold in in vitro enzyme activity. The levels of TAG and total lipid fatty acids in S. cerevisiae producing the N-terminally tagged BnaDGAT1.b at 72h were 53 and 28% higher than those in cultures producing untagged BnaA.DGAT1.b, respectively. These modified DGATs catalyzed the synthesis of up to 453mg fatty acid/L by this time point. The results will be of benefit in the biochemical analysis of recombinant DGAT1 produced through heterologous expression in yeast and offer a new approach to increase storage lipid content in yeast for industrial applications.