Fatty Acid Composition Of Polar Lipids Research Articles

Caprine milk fermentation enhances the antithrombotic properties of cheese polar lipids

The effect of fermentation on the antithrombotic properties of polar lipids in raw and pasteurised caprine milk was assessed through the production of various cheeses using the same starter culture. The total lipids (TL), total neutral lipids (TNL), and total polar lipids (TPL) were extracted from each milk and cheese and the TPL fatty acid profiles were analysed by GC–MS. It was determined that fermentation influenced the polar lipid fatty acid composition. The milk and cheese polar lipids exhibited potent antithrombotic activities with IC50 values ranging from 79 to 226 µg against platelet-activating factor (PAF) induced platelet aggregation. Finally, shotgun metagenomics determined the species-level microbial composition and functional potential of each milk and cheese. Several microbe-encoded phospholipid biosynthetic genes were identified in the most antithrombotic cheeses. Lactococcus lactis and other microbial species may play a significant role in determining the antithrombotic properties and fatty acid composition of caprine cheese polar lipids.

Total, Neutral, and Polar Lipids of Brewing Ingredients, By-Products and Beer: Evaluation of Antithrombotic Activities.

The in vitro antithrombotic properties of polar lipid constituents of malted grain (MG), pelleted hops (PH), brewer’s spent grain (BSG), spent hops (SH), wort, and bottled beer from the same production line were assessed in human platelets. The total lipids (TL) were extracted according to the Bligh and Dyer method and further separated into the total neutral lipids (TNL) and total polar lipids (TPL) extracts by counter-current distribution. The TL, TNL, and TPL extracts of all samples were assessed for their ability to inhibit platelet-activating factor (PAF) and thrombin-induced human platelet aggregation. The raw materials, by-products, wort, and beer lipid extracts all exhibited antithrombotic properties against PAF and thrombin. However, the beer TPL exhibited the lowest IC50 values against PAF-induced (7.8 ± 3.9 µg) and thrombin-induced (4.3 ± 3.0 µg) platelet aggregation indicating that these polar lipids were the most antithrombotic. The lipid extracts tended to be more bioactive against the thrombin pathway. The fatty acid content of all the TPL extracts were assessed using GC-MS. The fatty acid composition of the most bioactive TPL extracts, the wort and the beer, shared similar fatty acid profiles. Indeed, it was noted that fermentation seems to play a role in increasing the antithrombotic properties of polar lipids against PAF and thrombin by moderately altering the polar lipid fatty acid composition. Furthermore, the use of brewing by-products as a source of functional cardioprotective lipids warrants further investigation and valorisation.

Growth performance, carcass traits, physiochemical characteristics and intramuscular fatty acid composition of finishing Japanese black steers fed soybean curd residue and soy sauce cake.

This study was conducted to determine the effects of dietary soybean curd residue (SCR) and soy sauce cake (SSC) on the growth performance, carcass traits and physiochemical and intramuscular fatty acid (FA) characteristics in Japanese Black steers. Ten steers (29.7 ± 0.3 months old, 856.6 ± 24.4 kg body weight) were assigned to either treatment C, fed a conventional concentrate or T, fed the test diet including dried SCR and SSC for 3 months. In growth performance, dry matter (DM) intake and average daily gain, and carcass traits did not differ significantly between the treatments. Color of beef was affected by the dietary treatments and meat samples from T showed higher a(*) value and chroma than those in C. On FA composition, there was no significant difference between the treatments in neutral lipids, whereas in polar lipids, meat samples from T had higher C16:1 (P < 0.05) and tended to have higher C16:0 (P = 0.05) and C18:1 (P = 0.08), but lower C17:0 (P = 0.098), C18:2 (P = 0.06) and C20:4 (P = 0.07) than those from C. The study suggested that SCR and SSC could be used as a substitute for conventional concentrate and would influence meat color and intramuscular FA composition of polar lipids.

Levels of Arabidopsis thaliana Leaf Phosphatidic Acids, Phosphatidylserines, and Most Trienoate-Containing Polar Lipid Molecular Species Increase during the Dark Period of the Diurnal Cycle

Previous work has demonstrated that plant leaf polar lipid fatty acid composition varies during the diurnal (dark–light) cycle. Fatty acid synthesis occurs primarily during the light, but fatty acid desaturation continues in the absence of light, resulting in polyunsaturated fatty acids reaching their highest levels toward the end of the dark period. In this work, Arabidopsis thaliana were grown at constant (21°C) temperature with 12-h light and 12-h dark periods. Collision induced dissociation time-of-flight mass spectrometry (MS) demonstrated that 16:3 and 18:3 fatty acid content in membrane lipids of leaves are higher at the end of the dark than at the end of the light period, while 16:1, 16:2, 18:0, and 18:1 content are higher at the end of the light period. Lipid profiling of membrane galactolipids, phospholipids, and lysophospholipids by electrospray ionization triple quadrupole MS indicated that the monogalactosyldiacylglycerol, phosphatidylglycerol, and phosphatidylcholine classes include molecular species whose levels are highest at end of the light period and others that are highest at the end of the dark period. The levels of phosphatidic acid (PA) and phosphatidylserine classes were higher at the end of the dark period, and molecular species within these classes either followed the class pattern or were not significantly changed in the diurnal cycle. Phospholipase D (PLD) is a family of enzymes that hydrolyzes phospholipids to produce PA. Analysis of several PLD mutant lines suggests that PLDζ2 and possibly PLDα1 may contribute to diurnal cycling of PA. The polar lipid compositional changes are considered in relation to recent data that demonstrate phosphatidylcholine acyl editing.

Seasonal and growth stage changes in lipid and fatty acid composition in the multigeneration copepodDrepanopus pectinatusfrom Iles Kerguelen

AbstractChanges in adult weight, lipid and fatty acid composition per lipid class were studied over a complete seasonal cycle inDrepanopus pectinatusBrady. This copepod displayed a strong seasonality in adult individual weight and total lipid content. Stages C3 to adult from a summer cohort were compared in terms of lipid and fatty acid structure. Changes in lipid content were related to wax esters and polar lipids (PL) while triacylglycerols (TAG) and cholesterol remained minor constituents except at the end of winter. Changes in fatty acid composition of different lipid classes showed that food limitation in winter was high enough to affect 22:6n-3 (DHA) content in PL, and provoke accumulation of maximal percentages of bacterial marker as branched acids. Composition of TAG followed closely the changes in trophic interactions as diatom and flagellate markers dominated in spring and summer while bacterial and detritus particle markers dominated in late winter. The composition of wax esters followed the same seasonal succession but with a lower level of turn over time and shifted characteristics (bacterial markers) from winter to spring individuals when compared to TAG. Ontogenetic changes showed high triacylglycerols content in younger C3 stages and increasing wax esters with increasing developmental stages. Fatty acid composition of PL showed low percentages of EPA and DHA in stage C3, and recovery of high levels of DHA for stage C4 or 20:5n-3 (EPA) at stage C5. The same trend was observed for 18:4n-3. The reverse pattern was noted for the n-6 polyunsaturated acids (PUFA) suggesting a greater requirement in younger stages. Fatty acid partitioning between neutral and PL suggested essential fatty acids selective incorporation from neutral classes into membrane lipids.

Membrane fatty acids, reading and spelling in dyslexic and non-dyslexic adults

Increasing evidence implicates functional deficiencies or imbalances of omega-3 and omega-6 fatty acids in dyslexia. The associations between literacy skills and omega-3 and omega-6 fatty acid status were examined. 32 dyslexics and 20 controls completed standardised tests of reading and spelling and gave venous blood samples for analysis of the polar lipid fatty acid composition of red blood cell (RBC) membranes. Relationships between literacy skills and omega-3 and omega-6 concentrations were examined using rank-order correlations. Better word reading was associated with higher total omega-3 concentrations in both dyslexic and control groups. In dyslexic subjects only, reading performance was negatively associated with the ratio of arachidonic acid/eicosapentaenoic acid (ARA/EPA) and with total omega-6 concentrations. There were no significant differences in membrane fatty acid levels between the dyslexic and control subjects. However, the finding that omega-3 status was directly related to reading performance irrespective of dyslexia supports a dimensional view of this condition, and our results also suggest that it is the omega-3/omega-6 balance that is particularly relevant to dyslexia.

Effect of Nitrogen Limitation on the Growth and Lipid Composition of the Green Alga Botryococcus braunii Kutz IPPAS H-252

The effect of nitrogen limitation in a medium on the composition of intracellular lipids in the alga Botryococcus braunii Kutz IPPAS H-252 in the course of culture development was investigated. Under the conditions of nitrogen limitation, the alga under investigation accumulated lipids as triacylglycerols, and this process was accompanied by substantial changes in the total fatty acid (FA) composition, which were manifested in a decrease in trienoic acids (from 52.8–57.2 to 19.5–24.7% of total FAs) and an increase in the content of oleic (from 1.1–1.2 to 17.1–24.4%) and saturated (from 23.7–26.0 to 32.9–46.1%) acids. In the control culture, the directionality of FA redistribution was less marked, and these changes were noticed at the later stages of culture development. Under nitrogen limitation, marked changes in the FA composition of polar lipids occurred by the 13th day, and they were characterized by an increase in the content of saturated acids (up to 76.8%) and a dramatic decrease in the content of all polyenoic acids (up to 6.8%). The changes in the FA composition of triacylglycerols were noticed as early as by the 7th day; these changes consisted in an increase in the content of oleic acid, and its high content (28.4–38.4%) was maintained up to the end of culturing. In the control culture, triacylglycerols with a high content of oleic acid were found by the 13th day, although, by this time, the content of total lipids and triacylglycerols did not change.

Glycoalkaloids and acclimation capacity of hybrids between Solanum tuberosum and the incongruent hardy species Solanum commersonii.

F(1) and backcross hybrids between sexually incompatible species Solanum commersonii and Solanum tuberosum were characterized for glycoalkaloid content and capacity to cold acclimate. Glycoalkaloid (GA) analysis revealed that F(1) triploids and BC(1) pentaploids contained the glycoalkaloids of both parents. In BC(2) (near) tetraploids the situation was different, in that some hybrids produced the GAs of both parents, whereas others contained only the GAs of S. tuberosum. This suggested that the GAs from S. commersonii may be lost rapidly, and that they may have a simple genetic control. The total tuber GA content of BC(1) and BC(2) groups averaged quite acceptable levels (165.9 mg/kg in BC(1) and 192.8 mg/kg in BC(2)), with six genotypes having a GA content <200 mg/kg fresh weight. The F(1) triploid hybrids expressed a capacity to cold acclimate similar to S. commersonii, whereas BC(1) and BC(2) genotypes generally displayed an acclimation capacity higher than the sensitive parent but lower than S. commersonii. However, one BC(1) and two BC(2) genotypes with an acclimation capacity as high as S. commersonii were identified. The polar lipid fatty acid composition in S. commersonii and its hybrid derivatives showed that, following acclimation, there was a significant increase in 18:3. Correlation analysis between the capacity to cold acclimate and the increase in 18:3 was significant, suggesting that the increase in 18:3 can be used as a biochemical marker for the assisted selection of cold-acclimating genotypes in segregating populations.

Sediment microbial community structure and mercury methylation in mercury-polluted Clear Lake, California.

Spatial and temporal variations in sediment microbial community structure in a eutrophic lake polluted with inorganic mercury were identified using polar lipid fatty acid (PLFA) analysis. Microbial community structure was strongly related to mercury methylation potential, sediment organic carbon content, and lake location. Pore water sulfate, total mercury concentrations, and organic matter C/N ratios showed no relationships with microbial community structure. Seasonal changes and changes potentially attributable to temperature regulation of bacterial membranes were detectable but were less important influences on sediment PLFA composition than were differences due to lake sampling location. Analysis of biomarker PLFAs characteristic of Desulfobacter and Desulfovibrio groups of sulfate-reducing bacteria suggests that Desulfobacter-like organisms are important mercury methylators in the sediments, especially in the Lower Arm of Clear Lake.

Characterization of intestinal Na +–K +-ATPase in the gilthead seabream ( Sparus aurata L.). Evidence for a tissue-specific heterogeneity

Gilthead seabream intestine contains both a Mg 2+-dependent Na +–K +-ATPase which is completely inhibited by 1×10 −3 M ouabain, and also a residue-ATPase activity that is entirely ouabain-insensitive. The maximal activity of intestinal Na +–K +-ATPase (35.15 μmol inorganic phosphate (P i) mg protein −1 h −1) was observed in the microsomal fraction at 35°C, pH 7.5, 2–5 mM MgCl 2, 5 mM ATP, 10 mM K + and 200 mM Na +. The intestinal Na +–K +-ATPase of gilthead seabream exhibits similar characteristics to other teleost Na +–K +-ATPases regarding pH dependence, Mg 2+/ATP optimal ratios and ouabain sensitivity, but exhibits unusual sensitivity to ionic strength and cation promoted cooperative activation and higher affinity for magnesium and ATP when compared to other marine and euryhaline teleosts. The Arrhenius plot for intestinal Na +–K +-ATPase showed a break point at 15.41°C, with similar activation energies above and below the discontinuity point. The analysis of polar lipid fatty acid composition was correlated to the break point in the Arrhenius plot, suggesting a regulatory role of the lipid microenvironment on the enzyme activity. Finally, the kinetic characteristics, temperature-activity relationship, fatty acid composition and substrate dependence of intestinal Na +–K +-ATPase are compared with literature data and discussed on the basis of the differences between species and also between osmoregulatory tissues. It is concluded that the Na +–K +-ATPase of Sparus aurata is differently and specifically expressed between the osmoregulatory organs.

Changes in Polar Lipid Fatty Acid Composition during Cold Acclimation in ‘Midiron’ and ‘U3’ Bermudagrass

‘Midiron’ and ‘U3’ bermudagrass were exposed to conditions known to induce cold acclimation [e.g., 8/4°C (day/night) temperature, 10‐h photoperiod, 250 μmol m−2 s−1 photosynthetic photon flux density (PPFD)]. Tissues (leaves, crowns, and roots) were harvested stored frozen until processed. Polar membrane ids were isolated by thin layer chromatography, and fatty acids (FA) were separated and quantified by gas chromatography. Different organs from the same plant responded differentially to low temperature. Crowns showed the most dramatic changes in total FA content and composition and were the focus of this study. Overall, greater than 95% of the total FA content was accounted for by four FA species: palmitic acid (16:0), stearic acid (18:0), linoleic acid (18:2), and linolenic (18:3). Midiron (relatively cold‐tolerant) responded more rapidly to a greater extent than did U3 (relatively cold‐sensitive) as illustrated by the nearly four‐fold increase of unsaturated FA:saturated FA ratio for Midiron vs. U3, and by the significant difference between the double bond index of the two genotypes. These data suggest that specific desaturase enzymes (e.g., ω‐3 and ω‐6) are of fundamental importance in controlling membrane lipid/fatty acid composition in response to low temperature and ultimately in avoiding the winter damage suffered by bermudagrass along its northern boundary of adaptation.

Fatty Acid Composition of Meat from Rabbits Fed Diets with High Levels of Fat

The effects of high levels of dietary fat on the chemical and fatty acid composition of total, nonpolar, and polar lipids of rabbit meat have been studied. Four diets were used: control diet without added fat and three diets containing 3% (w/w) beef tallow, 3% soya and sunflower oleins, or 3% soya-bean oil. In order to increase dietary ether extract by 3%, these three experimental diets also contained 18% of heated whole soya-bean meal. Significant differences (P < 0.05) in the rabbit meat chemical composition were observed only between meat from rabbits fed control diet and rabbits fed the soya-bean oil plus whole soya-bean meal diet. However, the diet did influence total, nonpolar, and polar lipid fatty acid composition of the meat; C-18:1 and polyunsaturated fatty acids were the most affected. It was concluded that the enrichment of the rabbit diet with these specific fats produces rabbit meat with a higher degree of unsaturation than those obtained with conventional diets.

Effect of Dietary n-3 Fatty Acids on Weight Gain and Liver Polar Lipid Fatty Acid Composition of Fingerling Channel Catfish

A 10-wk experiment was conducted to determine the effect of supplementing a 5% tristearin basal diet with linoleic acid [18:2(n-6)], linolenic acid [18:3(n-3)], an n-3 highly unsaturated fatty acid (n-3 HUFA) mixture, cod liver oil, corn oil or linseed oil on growth and fatty acid composition of the liver polar lipid fraction of fingerling channel catfish (Ictalurus punctatus). The lowest weight gain was observed in fish fed the basal diet. Weight gain was improved by certain levels of supplemental n-3 fatty acids. Fish fed a diet containing 2% 18:3(n-3) grew at the same rate as fish fed a diet containing 2.5% cod liver oil plus 2.5% corn oil. The best growth rate was observed in fish fed diets containing either 5% cod liver oil or 5% linseed oil. Growth rate was depressed by supplementation with 4% 18:3(n-3) or 1.25% n-3 HUFA mix. No improvement in growth rate was observed with dietary 18:2(n-6). Dietary linolenate was converted to docosahexaenoic acid [22:6(n-3)]. The ratio of 20:3(n-9) to 22:6(n-3) of the fish showing good growth was less than 0.4. The data obtained in this experiment indicate that n-3 fatty acids are essential for channel catfish and that the 18:3(n-3) or n-3 HUFA dietary requirement is 1.0-2.0% or 0.5-0.75%, respectively.

Effect of paclobutrazol and chilling on leaf membrane lipids in cucumber seedlings

The effects of paclobutrazol on the leaf membrane lipid composition of seedlings of cucumber (Cucumis sativus L. cv. Victory) subjected to chilling temperatures were assessed. At a non‐injurious temperature (12.5°C), there was no difference in the polar lipid fatty acid composition or in the glycolipid, phospholipid or free sterol content of leaves from treated vs untreated seedlings, regardless of whether paclobutrazol was administered 1 or 7 days prior to analysis. In the latter case (7 days pretreatment), there were clear effects of the bioregulator on plant growth and morphology as well as on leaf chlorophyll content. At an injurious chilling temperature (5°C), desaturation of leaf polar lipid fatty acids was markedly reduced in both treated and untreated seedlings. Chilling at 5°C resulted in losses of fresh weight and membrane lipids in leaves of both groups of plants. These losses were either reversible or irreversible, depending upon the duration of chilling and of pretreatment with paclobutrazol. Seedlings pretreated with 10 μg ml−1 paclobutrazol generally sustained less chilling injury than untreated controls, as judged by the extent of wilting, necrosis and desiccation. This correlated with reduced losses of leaf fresh Weight and membrane lipids.

Polar lipid ester-linked fatty acid composition of Lake Vechten seston: an ecological application of lipid analysis

In order to relate the benthic lipid composition to possible sources in the water column, the sestonic communities of a monomictic lake were profiled using their saponifiable polar lipid fatty acids, which were identified by capillary gas chromatography-mass spectrometry (GC-MS). The epilimnion, dominated by the dinoflagellate alga Ceratium hirundella, was characterized by C20:5 and C22:6 polyunsaturated fatty acids. The photic anoxic metalimnion supported a radically different community, dominated by photosynthetic sulfur-oxidizing bacteria (Chromatium and Chloronema spp.) and a Synechococcus-like cyanobacterium, and was characterized by high concentrations of C16 and C18 monounsaturated fatty acids. The fatty acid compositions of the hypolimnetic seston and the sediment were qualitatively similar to that of the metalimnion. Methyl-branched acids, commonly found in eubacteria, increased with depth in the water column. The concentrations of several unusual fatty acids found in Desulfovibrio spp. Desulfobacter spp. and Desulfotomaculum spp. were inversely related to sulfate concentration in the metalimnion. After the water column mixed in the winter, steep gradients of respiratory terminal electron acceptors developed in the surface sediment and were reflected in the polar lipid fatty acid compositions. The results show that fatty acids derived from the membranes of epilimnetic phytoplankton were efficiently metabolized in the oxic portion of the water column. The fatty acids synthesized by prokaryotic microorganisms at and below the oxycline dominated the sediment. The polar lipid fatty acid composition of the sediment showed seasonal changes which can be associated with concentrations of terminal electron acceptors of microbial respiration, and thus with physiologically distinct bacterial groups.

Fatty-acid composition of polar lipids in fruit and leaf chloroplasts of ?16:3?- and ?18:3?-plant species

The fatty-acid composition of polar lipids from fruit and leaf chloroplasts was compared in five Solanaceous and two cucurbit species. The acylated fatty acids in monogalactosyl diglycerides (MGDG) from leaf chloroplasts of all five Solanaceous species included substantial amounts of Δ (7,10,13)-hexadecatrienoic acid (16:3). In contrast, the MGDG from fruit chloroplasts of the Solanaceae contained very little of this plastid-specific polyunsaturate, and instead included a proportionately greater percentage of linoleic acid (18:2). In MGDG from leaf chloroplasts of two cucurbits, α-linolenic acid (18:3) constituted 94-95% of the acylated fatty acids. Fruit-chloroplast galactolipids of the cucurbits had a greater abundance of 18:2, and hence a higher 18:2/18:3 ratio, than found in the corresponding leaf lipids. Among the phosphoglycerides, the unusual fatty acid Δ3-trans-hexadecenoate (trans-16:1) constituted from 15 to 24% of the acylated fatty acids in phosphatidyl glycerol (PG) from leaf chloroplasts (all species). In sharp contrast, trans-16:1 was virtually absent in PG from fruit chloroplasts of both Solanaceous and cucurbit species, and was replaced by a proportionate increase in the content of palmitate (16:0). The observed differences in the polar lipid fatty-acid composition of fruit and leaf chloroplasts are discussed in terms of the relative activity of several intrachloroplastic enzymes involved in lipid synthesis and fatty-acyl desaturation.