Lipid, fatty acid and protein utilization during lecithotrophic larval development of Lithodes santolla (Molina) and Paralomis granulosa (Jacquinot)

During the larval development of the subantarctic king crab, Lithodes santolla, and stone crab, Paralomis granulosa, we compared changes in the carbon, fatty acid and protein contents of larvae reared under constant conditions from hatching to metamorphosis, either in presence or absence of food (Artemia spp. nauplii). In both species the feeding condition had no influence on any of the chemical parameters studied, indicating a fully lecithotrophic (i.e. non-feeding) mode of development from hatching of the first zoea to metamorphosis of the late megalopa. Dry mass and carbon contents at hatching were similar in the larvae of both species, but L. santolla contained initially higher total amounts of fatty acids and protein than P. granulosa. Both species utilized considerable portions of their total fatty acid pool which decreased logarithmically throughout the time of development. At metamorphosis, it was almost exhausted in P. granulosa, while L. santolla had consumed only about 60%. Protein utilization, in contrast, was higher in L. santolla (40%) than in P. granulosa (20%). Triacylglycerol was the principal storage lipid in both species, accounting initially for about 75% of the lipid fraction; it was strongly utilized during larval development. Phospholipid constituted the second largest lipid class; it also decreased in P. granulosa, but to a lesser extent in L. santolla. The major fatty acids of both species were 18:1(n−9), 20:5(n−3) and 16:0 as well as, in lower proportions, 18:1(n−7), 22:6(n−3), 16:1(n−7) and 18:0. Monounsaturated fatty acids represented the dominant group in L. santolla, whereas P. granulosa contained similar amounts of mono- and polyunsaturated fatty acids. In L. santolla, monounsaturated fatty acids, especially 16:1(n−7), were preferentially utilized as compared to polyunsaturates. Due to a particularly strong lipid utilization in P. granulosa, all individual fatty acids were largely depleted at metamorphosis, showing similar extents of consumption. L. santolla had higher initial lipid and protein stores that seem to be used more economically as compared to P. granulosa.     

Enhanced algae growth in both phototrophic and mixotrophic culture under blue light

Biomass productivity and fatty acid methyl esters (FAME) derived from intracellular lipid of a Nannochloropsis sp. isolated from Singapore’s coastal waters were studied under different light wavelengths and intensities. Nannochloropsis sp., was grown in both phototrophic and mixotrophic (glycerol as the carbon source) culture conditions in three primary monochromatic light wavelengths, i.e., red, green and blue LEDs, and also in white LED. The maximum specific growth rate (μ) for LEDs was blue > white > green > red. Nannochloropsis sp. achieved a μ of 0.64 and 0.66 d⁻¹ in phototrophic and mixotrophic cultures under blue lighting, respectively. The intracellular fatty acid composition of Nannochloropsis sp. varied between cultures exposed to different wavelengths, although the absolute fatty acid content did differ significantly. Maximum FAME yield from Nannochloropsis sp. was 20.45% and 15.11% of dry biomass weight equivalent under photo- and mixotrophic culture conditions respectively for cultures exposed to green LED (550 nm). However, maximum volumetric FAME yield was achieved for phototrophic and mixotrophic cultures (i.e., 55.13 and 111.96 mg/l, respectively) upon cell exposure to blue LED (470 nm) due to highest biomass productivity. It was calculated that incremental exposure of light intensity over the cell growth cycle saves almost 20% of the energy input relative to continuous illumination for a given light intensity.     

Impact of feeding and starvation on the lipid metabolism of the Arctic pteropod Clione limacina

Feeding and starvation experiments were carried out with Clione limacina sampled in Kongsfjorden (Svalbard, Arctic) during summer 2002. Dry mass and lipid mass, lipid class and fatty acid compositions were analysed. Specimens of C. limacina used for the feeding study had a mean length of 25 mm, a dry mass (DM) of 13.7 mg, and a moderate lipid content of 12.1%DM. Animals were allowed to ingest only one individual of its exclusive prey, Limacina helicina which had 8.0 mm in diameter, 21.4 mg DM and 8.7% lipid of ash-free DM. Five days after feeding, the dry mass of C. limacina had increased from 13.7 to 25.3 mg which corresponds to an uptake of about 80% of the ash-free DM (14.3 mg) of L. helicina. Lipid mass increased from 1.5 to 3.9 mg which is almost two times more the ingested lipid from L. helicina (1.2 mg lipid). Thus, the major portion of lipids was synthesised de novo by C. limacina from non-lipid compounds. These lipids were triacylglycerols (TAG) and 1-O-alkyldiacylglycerol ethers (DAGE), increasing from low proportions of 6.1% and 5.7% to 42.3% and 25.8%, respectively. Considerable de novo synthesis was observed for the monounsaturated fatty acids 16:1(n − 7), 17:1(n − 8), 18:1(n − 9), and 18:1(n − 7) and the alkyl moiety 16:0. The increase in the polyunsaturated fatty acids 22:6(n − 3), 20:5(n − 3), and 18:4(n − 3) corresponded with the amount available by ingestion of L. helicina, supporting that C. limacina is not able to synthesise polyunsaturates. After 15 days of digestion, dry mass and lipids dropped almost back to the initial values.During the 100-day starvation experiment, two groups of animals were separately considered as storage lipid-rich and lipid-poor animals because of their large differences in the amount and proportion of TAG and DAGE. Storage lipid-rich C. limacina were only found until day 50, whereas lipid-poor animals were present throughout the experiment. In the lipid-rich specimens, the levels of TAG were about twice that of DAGE. The proportions of TAG decreased considerably during the 50 days of starvation (from 48.3% to 25.1% of total lipid). DAGE, varying between 16.5% and 20.5%, showed only a small decrease. The lipid-poor animals survived 100 days of starvation, exhibiting low initial amounts and proportions of storage lipids which were nearly exhausted at the end. In all C. limacina specimens, the total lipid content remained almost constant showing that lipid and non-lipid components were simultaneously utilised. This implies that body shrinkage may be an important adaptation to long-term starvation. Based on these results, it is possible to estimate the potential survival period of lipid-rich C. limacina under food limitation. A model, which considers maturity and reproduction (egg production), reveals that lipid-rich specimens might be able to survive up to 260 days without food.     

Effect of weight at slaughter and breed on beef intramuscular lipid classes and fatty acid profile

The effect of slaughter weight and breed on the composition of intramuscular fat (IMF) of seven Spanish cattle breeds was studied. Lipid classes and fatty acids were evaluated in young bulls of seven local Spanish cattle breeds, Asturiana, Avileña, Morucha, Parda Alpina, Pirenaica, Retinta and Rubia Gallega, slaughtered at a live weight of 320 kg (veal type) and 550 kg (yearling bull type). Higher slaughter weight and early maturating breeds produced higher IMF content in the longissimus muscle (P < 0.001), which was linked to a reduction in phospholipids, monoglycerides, diglycerides, cholesterol and free-fatty acids content, but an increase in triacylglycerols. Besides, heavier animals displayed a higher percentage of saturated and monounsaturated fatty acids (MUFA), but a lower polyunsaturated fatty acids (PUFA) percentage (P < 0.001). The increase in triglycerides (TG), saturated fatty acids (SFA) and MUFA illustrates the increasing importance of lipid storage as fattening proceeds and the acquisition of ruminal functionality. The feeding system based on cereals had a strong influence on the fatty acid profile, giving the studied beef a relatively high PUFA/SFA and n-6/n-3 ratios.     

Identification of key nutrients for gonadal development by comparative analysis of proximate composition and fatty/amino acid profile in tissues and eggs of Chinese sturgeon (Acipenser sinensis Gray, 1835)

The present study was conducted to characterize the proximate composition and fatty/amino acid profile in muscle, liver and gonads obtained from farmed male and female Chinese sturgeon (Acipenser sinensis) with gonad development at stage II, and to discern the key nutrients for gonads by comparing the nutrients between tissues and between fish at different gonad stages. Chinese sturgeon were reared in an outdoor circular cement pool at temperatures ranging from 8°C to 26°C, and fed with 70% artificial diets and 30% frozen forage fish at a feeding rate of 0.2%–1.5% body weight according to the water temperature. Three male and three female A. sinensis were sampled for analyses. Results showed that the lipid content in gonads was significantly higher than in other tissues in both males and females (p < .05). The protein content in male and female gonads was significantly lower than that in the muscle (p < .05). Total content of mono‐unsaturated fatty acids (MUFA) in females was significantly higher than in males (p < .05), while the total content of n‐6 PUFA in females was significantly lower than in males (p < .05). Palmitic acid (C16:0) and oleic acid (C18:1n9) were the major saturated fatty acid (SFA) and MUFA, respectively, in both females and males. The contents of C18:2n6, C20:4n6 (ARA), C18:3n3 and C22:6n3 (DHA) in male gonads were significantly higher than in females (p < .05). The contents of ARA, EPA and DHA in gonads were lower, possibly playing a pivotal role in gonad development. Comparing the nutrients of ovaries in broodstocks at stages III and IV and the eggs at stage IV, the present study suggests that the lipid and fatty acid profile in fish is vital to the gonad development and that proper improvement of lipid nutrition in the broodstock diet to provide sufficient energy and essential fatty acids would be beneficial for the gonad development of Acipenser sinensis.     

Effect of sex,dietary glycerol or dietary fat during late fattening,on fatty acid composition and positional distribution of fatty acids within the triglyceride in pigs

The effect of sex, source of saturated fat (lard v. palm oil) and glycerol inclusion in the fattening diet on composition and fatty acid positional distribution in the triglyceride molecule was studied in pigs from 78 to 110 kg BW. Average daily gain and carcass characteristics, including ham and loin weight, were not affected by dietary treatment but sex affected backfat depth (P<0.01). A significant interaction between sex and glycerol inclusion was observed; dietary glycerol increased lean content in gilts but not in barrows (P<0.05 for the interaction). Individual and total saturated fatty acid (SFA) concentrations were greater in barrows than in gilts. In contrast, the concentration of total polyunsaturated fatty acids (PUFA) and of C18:2n-6, C18:3n-3, C20:3n-9 and C20:4n-6 in the intramuscular fat (IMF) was higher (P<0.05) in gilts than in barrows. Sex did not affect total monounsaturated fatty acids (MUFA) concentration in the IMF. The proportion of SFA in the subcutaneous fat (SF) was higher in barrows than in gilts (P<0.001). Within the individual SFA, sex affected only the concentrations of C14:0 and C16:0 (P<0.001). Dietary fat did not affect total SFA or PUFA concentrations of the IMF but the subcutaneous total MUFA concentration tended to be higher (P=0.079) in pigs fed lard than in pigs fed palm oil. Dietary glycerol increased total MUFA and C18:1n-9 concentration in the IMF and increased total MUFA and decreased C18:2n-6, C18:3n-3 and total PUFA concentrations in the SF. The data indicate that altering the fatty acid composition of the triglyceride molecule at the 2-position, by dietary intervention during the fattening phase, is very limited.     

Incorporation of bacterial fatty acids and changes in a wax ester-based omnivory index during a long-term incubation experiment with Calanus glacialis Jaschnov

We traced the incorporation of fatty acid biomarkers into Calanus glacialis Jaschnov (CV) during a long-term incubation experiment using bacterivorous dinoflagellates and diatoms as food. Copepods fed Oxyrrhis marina Dujardin during a 3-week acclimation period developed an omnivorous lipid composition, relative to wild-captured copepods, characterized by significant losses of polyunsaturated fatty acids (PUFA) and diatom fatty acids [16:4(n−1), 20:5(n−3)], and increases in saturated fatty acids (SFA) and 18:1(n−7). Levels of a wax ester-based omnivory index [unsaturation coefficient (UC)], verified by gas chromatography (GC), also decreased in response to the relatively PUFA-poor dinoflagellate. After half of the copepods were switched to a diet comprised of the diatom Thalassiosira hispida Syvertsen (PUFA-rich), the data showed reversal to a more herbivorous lipid composition (increases in UC and relative amounts of PUFA and diatom fatty acids). We assert that UC, derived from routine thin-layer chromatography analysis (Iatroscan) can quickly determine in situ feeding strategies (i.e., degree of omnivory) of wax ester-storing copepods. None of the eight odd and/or branched fatty acids (OBFA) initially detected in C. glacialis increased in response to a diet of O. marina which was rich in these compounds [mainly iso (i)-15:0 and anteiso (ai)-15:0]. Lack of transfer of these and other fatty acids [e.g., 22:6(n−3)] could be related to the physiological state of the copepods (early diapause). We suggest that the bacterial fatty acid 18:1(n−7) may be more useful in inferring connections between Calanus spp. and the microbial food web than the odd and/or branched chains.     

Effects of agronomic application of olive mill wastewater in a field of olive trees on carbohydrate profiles, chlorophyll a fluorescence and mineral nutrient content

Olive mill wastewater (OMW) management is a serious environmental issue for the Mediterranean area where there is the most production of olive oil. OMW contains a high organic load, substantial amounts of plant nutrients but also several compounds with recognized toxicity towards living organisms. Moreover, OMW may represent a low cost source of water. We studied the influence of irrigation with OMW (amounts applied: 30, 60, 100 and 150 m³ h⁻¹) in a field of olive trees on root colonization, photosynthesis, chlorophyll fluorescence, leaf nutrient concentration and soluble carbohydrate. The soil fatty acid methyl ester (FAME) 16:1ω5 was used to quantify biomass of arbuscular mycorrhizal (AM) fungi and the root FAME 16:1ω5 analysis was used as index for the development of colonization in the roots. Agronomic application of OMW decreased significantly the abundance of the soil FAME 16:1ω5 and the root FAME 16:1ω5 in the soil amended with 60, 100 and 150 m³ ha⁻¹ OMW. Decreased root FAME 16:1ω5 due to OMW amendment was associated with a significant reduction of tissue nutrient concentrations in the olive trees. The highest application of OMW to the soil reduced significantly the olive trees uptake of N, P, K, Ca, Mg, Fe, Cu, Mn and Zn. Land spreading of OMW increased concentration of soluble carbohydrate in the olive leaves, mostly due to decreased sink demand for carbon by the root. In the olive trees amended with 150 m³ ha⁻¹ OMW, net CO₂ uptake rate (A), quantum yield of photosystem II electron transport (Φ_PSII), maximal photochemical efficiency of photosystem II (Fv/Fm), photochemical quenching (q_p) and the electron transport rate (ETR) were significantly depressed, whereas non-photochemical quenching (NPQ) was found to increase. Taken with data from experiments in field conditions, our results suggest that agronomic application of OMW alters the functioning of arbuscular mycorrhizas and can even disrupt the relationship between AM fungi and olive trees.     

Spatial and temporal variation of the fatty acid composition of Patella spp. (Gastropoda: Prosobranchia) soft bodies and gonads

This study evaluated the effects of season and spatial distribution on the fatty acid composition of Patella depressa gonads and Patella spp. soft body tissue. The results show that the quantitatively most important fatty acids were the saturated fatty acids (SFA) 16:0, 14:0 and 18:0; the monounsaturated fatty acids (MUFA) 18:1(n-7), 18:1(n-9), 16:1(n-7) and 20:1(n-9) and the polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA 20:5(n-3)), and arachidonic acid (ARA 20:4(n-6)). P. depressa and P. ulyssiponensis soft body fatty acid profiles revealed significant differences between sexes; males showed significantly higher percentages of PUFA, highly unsaturated fatty acids (HUFA), (n-3) fatty acids and ARA, while in females significantly higher proportions of MUFA were found. Analysis of variance on the fatty acid composition of P. depressa gonads revealed significant differences between sexes, which were more marked than when the whole body was analysed. Males showed a significantly higher percentage of PUFA, HUFA, fatty acids from the (n-3) and (n-6) series, ARA and EPA, while females were seen to have higher proportions of SFA, MUFA and total fatty acid methyl esters (FAME). Some variability was seen to occur due to shore location and seasons, but these effects were not so obvious.     

Fatty acid composition in matrix vesicles and in microvilli from femurs of chicken embryos revealed selective recruitment of fatty acids

Hypertrophic chondrocytes participate in matrix mineralization by releasing matrix vesicles (MVs). These MVs, by accumulating Ca²⁺ and phosphate initiate the formation of hydroxyapatite. To determine the types of lipids essential for mineralization, we analyzed fatty acids (FAs) in MVs, microvilli and in membrane fractions of chondrocytes isolated from femurs of chicken embryos. The FA composition in the MVs was almost identical to that in microvilli, indicating that the MVs originated from microvilli. These fractions contained more monounsaturated FAs especially oleic acid than in membrane homogenates of chondrocytes. They were enriched in 5,8,11-eicosatrienoic acid (20:3n−9), in eicosadienoic acid (20:2n−6), and in arachidonic acid (20:4n−6). In contrast, membrane homogenates from chondrocytes were enriched in 20:1n−9, 18:3n−3, 22:5n−3 and 22:5n−6. Due to their relatively high content in MVs and to their selective recruitment within microvilli from where MV originate, we concluded that 20:2n−6 and 20:3n−9 (pooled values), 18:1n−9 and 20:4n−6 are essential for the biogenesis of MVs and for bone mineralization.     

Omega-3 fatty acids and metabolic syndrome: Effects and emerging mechanisms of action

Epidemiological, human, animal, and cell culture studies show that n−3 fatty acids, especially α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), reduce the risk factors of cardiovascular diseases. EPA and DHA, rather than ALA, have been the focus of research on the n−3 fatty acids, probably due to the relatively inefficient conversion of ALA to EPA and DHA in rodents and humans. This review will assess our current understanding of the effects and potential mechanisms of actions of individual n−3 fatty acids on multiple risk factors of metabolic syndrome. Evidence for pharmacological responses and the mechanism of action of each of the n−3 fatty acid trio will be discussed for the major risk factors of metabolic syndrome, especially adiposity, dyslipidemia, insulin resistance and diabetes, hypertension, oxidative stress, and inflammation. Metabolism of n−3 and n−6 fatty acids as well as the interactions of n−3 fatty acids with nutrients, gene expression, and disease states will be addressed to provide a rationale for the use of n−3 fatty acids to reduce the risk factors of metabolic syndrome.     

Bile acids override steatosis in farnesoid X receptor deficient mice in a model of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, and the pathogenesis is still not well known. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily and plays an essential role in maintaining bile acid and lipid homeostasis. In this study, we study the role of FXR in the pathogenesis of NFALD. We found that FXR deficient (FXR^−/−) mice fed methionine- and choline-deficient (MCD) diet had higher serum ALT and AST activities and lower hepatic triglyceride levels than wild-type (WT) mice fed MCD diet. Expression of genes involved in inflammation (VCAM-1) and fibrosis (α-SMA) was increased in FXR^−/− mice fed MCD diet (FXR^−/−/MCD) compared to WT mice fed MCD diet (WT/MCD). Although MCD diet significantly induced hepatic fibrosis in terms of liver histology, FXR^−/−/MCD mice showed less degree of hepatic steatosis than WT/MCD mice. Moreover, FXR deficiency synergistically potentiated the elevation effects of MCD diet on serum and hepatic bile acids levels. The super-physiological concentrations of hepatic bile acids in FXR^−/−/MCD mice inhibited the expression of genes involved in fatty acid uptake and triglyceride accumulation, which may be an explanation for less steatosis in FXR^−/−/MCD mice in contrast to WT/MCD mice. These results suggest that hepatic bile acids accumulation could override simple steatosis in hepatic injury during the progression of NAFLD and further emphasize the role of FXR in maintaining hepatic bile acid homeostasis in liver disorders and in hepatic protection.     

Ultraviolet light increases mortality of nematode larvae and can explain patterns of larval availability at pasture

Despite its documented effects on the viability of living organisms, the impact of ultraviolet (UV) light on the survival of parasitic nematode larvae has received surprisingly little attention. Infective L3s of the trichostrongyloid nematodes Haemonchus contortus, Teladorsagia circumcinta and Nematodirus battus, suspended in water, were exposed to direct UV irradiation in two experiments. In the first, during 6 days of constant illumination with UVA lamps at intensities simulating sunlight at ground level, the mortality rate was increased up to 100-fold compared with controls sheltered by UV-impermeable perspex. Significant differences in mortality rates were detected between the three species, with H. contortus the least sensitive. In the second experiment, larvae were exposed to natural sunlight during the temperate spring and summer, for 24-h periods on seven separate days representing a range of weather and UV doses. Mortality was again increased by UV exposure in all species, but was less in H. contortus than in T. circumcincta or N. battus. At higher daily UV doses, the mortality rate was on average 2.27 times higher in exposed larvae than in sheltered controls. Increased mortality caused by UV irradiation could help to explain patterns of abundance of infective stages at pasture, especially pronounced population declines in spring when solar radiation rises rapidly and temperature is still low. Implications for the epidemiology of gastrointestinal nematode infection in ruminants, and for trade-offs in parasite life history, are discussed.     

Correlation between body size and fatty acid and essential amino acid composition of round goby (Neogobius melanostomus) and monkey goby (Neogobius fluviatilis) from the Rhine River (Germany)

In this study correlations between body size and muscle fatty and amino acid content of two species of goby, round goby (Neogobius melanostomus) and monkey goby (Neogobius fluviatilis) caught from river Rhine (Germany) were investigated. Among saturated fatty acids (SFAs), mono- (MUFA) and polyunsaturated fatty acids (PUFAs) only SFAs were significantly higher in round goby than monkey goby (P < 0.05). In general, the correlation between body size of both gobies and the content of most of the individual fatty acids was not significant. In monkey goby, the content of palmitic acid (C16:0) and oleic acid (C18:1 n-9) was positively correlated with weight (r = 0.43) and total length (r = ?0.58), respectively, and the content of docosahexaenoic acid (DHA) increased with condition factor (r = 0.50). The content of threonine, arginine, valine, phenylalanine and isoleucine in monkey goby was higher than those of round goby (P < 0.05). In round goby the three essential amino acids arginine, valine and leucine were positively (P < 0.05) correlated with body length, which indicates that longer round gobies are of higher nutritional value.     

Genetic parameters of backfat fatty acids and carcass traits in Large White pigs

Subcutaneous fat thickness and fatty acid composition (FAC) play an important role on seasoning loss and organoleptic characteristics of seasoned hams. Dry-cured ham industry prefers meats with low contents of polyunsaturated fatty acids (PUFA) because these negatively affect fat firmness and ham quality, whereas consumers require higher contents in those fatty acids (FA) for their positive effect on human health. A population of 950 Italian Large White pigs from the Italian National Sib Test Selection Programme was investigated with the aim to estimate heritabilities, genetic and phenotypic correlations of backfat FAC, Semimembranosus muscle intramuscular fat (IMF) content and other carcass traits. The pigs were reared in controlled environmental condition at the same central testing station and were slaughtered at reaching 150 kg live weight. Backfat samples were collected to analyze FAC by gas chromatography. Carcass traits showed heritability levels from 0.087 for estimated carcass lean percentage to 0.361 for hot carcass weight. Heritability values of FA classes were low-to-moderate, all in the range 0.245 for n-3 PUFA to 0.264 for monounsaturated FA (MUFA). Polyunsaturated fatty acids showed a significant genetic correlation with loin thickness (0.128), backfat thickness (−0.124 for backfat measured by Fat-O-Meat’er and −0.175 for backfat measured by calibre) and IMF (−0.102). Obviously, C18:2(n-6) shows similar genetic correlations with the same traits (0.211 with loin thickness, −0.206 with backfat measured by Fat-O-Meat’er, −0.291 with backfat measured by calibre and −0.171 with IMF). Monounsaturated FA, except with the backfat measured by calibre (0.068; P<0.01), do not show genetic correlations with carcass characteristics, whereas a negative genetic correlation was found between MUFA and saturated FA (SFA; −0.339; P<0.001). These results suggest that MUFA/SFA ratio could be increased without interfering with carcass traits. The level of genetic correlations between FA and carcass traits should be taken into account in dealing with the development of selection schemes addressed to modify carcass composition and/or backfat FAC.     

Comparison of lipid content and fatty acid composition in muscle and liver of two notothenioid fishes from Admiralty Bay (Antarctica): an eco-physiological perspective

During Antarctic summer, total lipids (g/100 g dry matter) in Notothenia coriiceps (n=18) and Lepidonotothen nudifrons (n=10) were low (6.1 and 4.7 in muscle), which is typical of Antarctic benthic species. The liver of female N. coriiceps was heavier and contained more lipids per dry weight than the liver of males. The fatty acid composition of N. coriiceps and L. nudifrons was dominated by polyunsaturated fatty acids (PUFA, respectively, 44 and 49% of total fatty acids in muscle, 31 and 46% in liver), which included primarily C20:5n-3 (18 and 19% in muscle, 13 and 18% in liver) and C22:6n-3 (15 and 19% in muscle, 12 and 20% in liver). In L. nudifrons, the levels of some unsaturated fatty acids increased with age and size. The high percent unsaturation (PUFA+MUFA, 78 and 80% in muscle, 82 and 80% in liver) is a response to low water temperature (-0.4°C). Fish fatty acid profiles reflect fatty acid profiles of the diet (amphipods, macroalgae and fish).     

Coenzyme A and its thioester pools in fasted and fed rat tissues

The possibility of elevating the omega-3 fatty acid contents in mammalian cells using the sdd17 gene from Saprolegnia diclina was investigated in the current study. The nucleotide sequence of the sdd17 gene was optimized and the pSDD17-IRES-GFP plasmid was introduced into murine 3T3 fibroblast cells by electroporation, following which its heterologous expression was evaluated by fatty acid analysis. Evaluation of GFP co-expression and RT-PCR analysis indicated that sdd17 could be expressed at very high levels in mammalian cells. Total cellular lipid analysis of transformed cells fed with arachidonic acid (20:4 n − 6) as a substrate showed that the sdd17 expression resulted in an 82-155% (p < 0.05) increase in eicosapentaenoic acid (20:5 n − 3) compared with the control. This expression also reduced the arachidonic acid/(eicosapentaenoic + docosapentaenoic + docosahexaenoic acid) ratio from approximately 4:1 in control cells to 1.5:1 in sdd17-transformed cells (p < 0.05). This study demonstrated that the foreign sdd17 gene from EPA-rich fungus was expressed at a high efficiency and caused the omega-3 fatty acid contents in mammalian cells to be elevated. It also provided a basis for potential applications of this gene in animal transgenesis.     

Biochemical and Molecular Characterization of Some Centaurea Species Growing in the Eastern Anatolia Region of Turkey

Random amplified polymorphic DNA (RAPD) and fatty acid (FAME) profiles were used to examine phenotypic and genetic relationships among 16 Centaurea species growing wild in the eastern Anatolia region of Turkey. Thirteen decamer primers were used to examine polymorphism. According to the RAPD results, 99 amplicons in the size range of 50–1000 bp were produced from 13 primers in 16 Centaurea species. Genetically four distinct groups were determined among the species of Centaurea, which represents high genetic variation. In the 16 species, 14 fatty acids were determined according to FAME results. Both FAME and RAPD results showed that C. virgata is genetically different from other species. The differences in the composition of fatty acids among Centaurea species suggest that fatty acid profiles could be used to differentiate among some of these species. Results of this study show that RAPD and FAME analyses are consistent.     

Linoleate 9R-dioxygenase and allene oxide synthase activities of Aspergillus terreus

Oxygenation of linoleic acid by Aspergillus terreus was studied with LC-MS/MS. 9(R)-Hydroperoxy-10(E),12(Z)-octadecadienoic acid (9R-HpODE) was identified along with 10(R)-hydroxy-8(E),12(Z)-octadecadienoic acid and variable amounts of 8(R)-hydroxy-9(Z),12(Z)-octadecadienoic acid. 9R-HpODE was formed from [11S-²H]18:2n − 6 with loss of the deuterium label, suggesting antarafacial hydrogen abstraction and oxygenation. Two polar metabolites were identified as 9-hydroxy-10-oxo-12(Z)-octadecenoic acid (α-ketol) and 13-hydroxy-10-oxo-11(E)-octadecenoic acid (γ-ketol), likely formed by spontaneous hydrolysis of an unstable allene oxide, 9(R),10-epoxy-10,12(Z)-octadecadienoic acid. α-Linolenic acid and 20:2n − 6 were oxidized to hydroperoxy fatty acids at C-9 and C-11, respectively, but α- and γ-ketols of these fatty acids could not be detected. The genome of A. terreus lacks lipoxygenases, but contains genes homologous to 5,8-linoleate diol synthases and linoleate 10R-dioxygenases of aspergilli. Our results demonstrate that linoleate 9R-dioxygenase linked to allene oxide synthase activities can be expressed in fungi.     

Characterization of Armillaria spp. from peach orchards in the southeastern United States using fatty acid methyl ester profiling

Limited information is available regarding the composition of cellular fatty acids in Armillaria and the extent to which fatty acid profiles can be used to characterize species in this genus. Fatty acid methyl ester (FAME) profiles generated from cultures of A. tabescens, A. mellea, and A. gallica consisted of 16–18 fatty acids ranging from 12–24 carbons in length, although some of these were present only in trace amounts. Across the three species, 9-cis,12-cis-octadecadienoic acid (9,12-C18:2), hexadecanoic acid (16:0), heneicosanoic acid (21:0), 9-cis-octadecenoic acid (9-C18:1), and 2-hydroxy-docosanoic acid (OH-22:0) were the most abundant fatty acids. FAME profiles from different thallus morphologies (mycelium, sclerotial crust, or rhizomorphs) displayed by cultures of A. gallica showed that thallus type had no significant effect on cellular fatty acid composition (P > 0.05), suggesting that FAME profiling is sufficiently robust for species differentiation despite potential differences in thallus morphology within and among species. The three Armillaria species included in this study could be distinguished from other lignicolous basidiomycete species commonly occurring on peach (Schizophyllum commune, Ganoderma lucidum, Stereum hirsutum, and Trametes versicolor) on the basis of FAME profiles using stepwise discriminant analysis (average squared canonical correlation = 0.953), whereby 9-C18:1, 9,12-C18:2, and 10-cis-hexadecenoic acid (10-C16:1) were the three strongest contributors. In a separate stepwise discriminant analysis, A. tabescens, A. mellea, and A. gallica were separated from one another based on their fatty acid profiles (average squared canonical correlation = 0.924), with 11-cis-octadecenoic acid (11-C18:1), 9-C18:1, and 2-hydroxy-hexadecanoic acid (OH-16:0) being most important for species separation. When fatty acids were extracted directly from mycelium dissected from naturally infected host tissue, the FAME-based discriminant functions developed in the preceding experiments classified all samples (n = 16) as A. tabescens; when applied to cultures derived from the same naturally infected samples, all unknowns were similarly classified as A. tabescens. Thus, FAME species classification of Armillaria unknowns directly from infected tissues may be feasible. Species designation of unknown Armillaria cultures by FAME analysis was identical to that indicated by IGS-RFLP classification with AluI.