Significant Differences In Lipid Content Research Articles

Lipidomic analysis of facial skin surface lipids in acne in young women.

Alterations in the secretion and composition of skin surface lipids (SSL) are closely associated with the development of acne. Lipidomics is a useful tool to analyse the SSL of different types of acne. Our previous study found that phosphatidylserine and triacylglycerols dominate SSL changes in male acne and infantile acne, respectively. However, skin surface lipids as well as specific lipids in female acne patients remain to be investigated. To analyse and compare the SSL profile of acne women and healthy women and to discuss the involvement of differential lipids in acne development. Systematic lipidomics approach (high-throughput UPLC-QTOF-MS technology in combination with multivariate data analysis methods) was used to analyse the variations of SSL between acne and healthy groups. Analysis revealed significant differences in lipid content and composition between the two groups. Further analysis showed that levels of 13 individual lipids were significantly different and followed the same trend as the main class and subclasses. The largest individual contributor to the subgroup was triglycerides (TG) and phosphatidylinositol (PI). In addition, female acne patients exhibited reduced ceramide chain length (CCL) and increased levels of unsaturated fatty acids (UFAs), The changes of CCL in female acne are identical to male acne. There was a significantly higher level of TG and PI in the SSL of female acne patients. A reduction in CCL and an increase in UFAs content might contribute to the reduced skin barrier function in acne patients. The results suggest that female acne may have different pathogenesis than male acne.

Influence of Different Cooking Methods on Fillet Steak Physicochemical Characteristics

Meat is a source of protein widely consumed by the population in many countries due mainly to the nutritional aspects, sensory characteristics, and cultural aspects. The meat cooking preparation can promote significant changes in the meat’s chemical composition and physical characteristics. Such transformations can impact both the acceptance of the product and consumers’ health. Due to the different thermal processes altering the physical-chemical characteristics of meat, the present study aimed to evaluate the physicochemical characteristics of fillet steak submitted to different cooking methods: pan-frying with and without oil and air fryer. We performed the analysis to evaluate the physicochemical characteristics considering moisture, lipid, protein, ash, sodium, and potassium content, cooking loss index and colorimetry in three degrees of doneness of the meat, rare, medium, and well done. The fillet steak prepared by pan-frying with oil lost higher moisture and weight than the other samples. The air fryer method presented the highest moisture content. There was a significant difference in lipid content in which the pan-frying with oil fillet steak showed the highest amount of lipids. The pan-frying with oil steak fillet also presented more changes in the colorimetric parameters evaluated compared to the other samples. The pan-frying with oil cooking method promoted more pronounced changes in the steak fillet, and the cooking air fryer, the changes in meat quality are less pronounced. Therefore, the air fryer can be considered a good alternative for cooking meat.

Lipid content and fatty acid composition in female American shad,Alosa sapidissima, at different stages of ovarian development under reared conditions

The fatty acid accumulation in broodstock influences the fecundity of spawners as well as egg quality. A comprehensive understanding of the lipid and fatty acid changes in broodstock during the reproductive period can increase our knowledge of the nutritional requirements in artificial breeding programs. The study assessed the lipid and fatty acid compositions of muscle, liver and ovary of American shad at different stages of reproductive development under reared conditions. The results indicated that there were significant differences in lipid content among ovary, liver and muscle. Mean total lipid levels in ovary, liver and muscle were 15.92%–10.87%, 13.62%–6.89%, 10.39%–6.11% respectively. During the development season, the total lipid content in muscle in stages V and VI were significantly lower than those in stages II and III. The total lipid content in liver in stages IV, V and VI was significantly lower than in stages II and III, whereas the total lipid content in the ovary increased significantly as the gonad developed and reached its highest value at stage V. From II to VI stage, the liver content of docosahexaenoic acid (DHA) decreased and the ovarian content of DHA increased, whereas the content of eicosapentaenoic acid (EPA) remained relatively constant. The content of C16:0 and C18:1n-9 decreased in muscle and liver, but significantly increased in ovary. It is therefore suggested that the lipids were preferentially transferred from muscle and liver to ovary beginning in stage IV as the gonad matured. At stage IV, the lipid transfer accelerated, and saturated and unsaturated fatty acids, such as C16:0, C18:1n-9, DHA, EPA and arachidonic acid, were selectively transferred to and conserved in ovaries.

Comparison of Body Composition and Fatty Acid Profiles between Wild and Cultured Rio Grande Silvery Minnows

AbstractFederally endangered Rio Grande Silvery Minnows (RGSM; Hybognathus amarus) were raised in one of three culture regimes: intensively, with only a hatchery diet; semi-intensively with access to natural food and hatchery diet supplementation; and with only natural food available at the Los Lunas Silvery Minnow Refugium (Los Lunas, New Mexico), a naturalized conservation refugium designed to mimic the natural environment of the RGSM in the Rio Grande. The project compared each culture regime and assessed differences and similarities in lipid and fatty acid content between feeding an artificial diet and consumption of natural food items in this species. After 117 d, whole-body lipid levels and fatty acid profiles were measured in each group and compared with values for wild RGSM. Fish fed the hatchery diet exclusively or as supplementary feed had significantly higher percent lipid (15.5% ± 0.5% and 10.6% ± 0.1%, respectively) than fish raised without access to the diet. Both groups had significantly higher percent lipid than fish raised in the refugium or wild fish (8.3% ± 0.1% and 7.8% ± 0.2%, respectively). Condition factor differed among groups and was highest in fish fed the hatchery diet (1.00) followed by fish supplemented with the hatchery diet (0.93), refugium fish (0.91), and wild fish (0.90). In this respect, refugium fish appeared more similar to wild fish than fish fed the hatchery diet or offered the diet as a supplement. Comparison of fatty acid profiles among groups showed marked differences among wild fish, refugium fish, and those fed the hatchery diet, either exclusively or as supplementary feed. Total omega-3 fatty acids, expressed as percentage of total fatty acids, were highest in wild fish but similar among other groups. Total omega-6 fatty acids showed an opposite trend, with five to nine times higher percentages of linoleic acid observed among fish from the three culture regimes compared with wild fish. Significant differences in lipid content and fatty acid composition between wild RGSM and cultured silvery minnows reflected their respective diets and culture regimes. Given similarities in fat content and condition factor with wild RGSM, we conclude that fish in the refugium do not require supplemental feeding with an artificial diet for this type of naturalized conservation management. Results from this study show that RGSM readily forage on natural food items present and also artificial feed when available, indicating dietary plasticity, which is advantageous for fish culture and future recovery.

Validating the use of biopsy sampling in contamination assessment studies of small cetaceans

Remote biopsy sampling is the most common technique for acquiring samples from free-ranging marine mammals. However, such techniques may result in variable sampling being sometimes superficial skin and blubber biopsies. For decades, blubber has been used to monitor the exposure of marine mammals to persistent organic pollutants (POPs), but little is known regarding the variability of POPs as a function of blubber depth in small cetaceans and the available literature offers variable results. Thus, the aim of the present study was to validate biopsy sampling for monitoring contaminant concentrations in small, free-ranging cetaceans. Samples from the dorsal blubber of 10 incidentally captured Atlantic spotted dolphins (Stenella frontalis) were separated into two different layers (outer and inner) to investigate the influence of sampling depth on POP concentrations. POP concentrations were compared to those of the full blubber layer. The results revealed no significant differences in lipid content between males and females or among the inner, outer and full blubber layers (p>0.05). Moreover, the wet and lipid weight concentrations of all POP classes analysed [i.e. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), chlordanes (CHLs) and mirex] did not differ significantly with blubber depth (p>0.05). POP classes followed the same decreasing order of wet weight concentrations in blubber layers and full blubber: PCBs>DDTs>PBDEs>mirex>HCB>HCHs>CHLs. Moreover, there was a low degree of differentiation in the accumulation of POP congeners. The present findings indicated that the distribution of contaminants was homogenous with blubber depth, which validates the use of biopsy sampling for the assessment of contaminants in small cetaceans.

Trophodynamics of euphausiids in the Amundsen Sea during the austral summer by fatty acid and stable isotopic signatures

The Amundsen Sea is characterized by a continental shelf, long-term sea ice, and many coastal polynyas with high biological productivity. Euphausia superba and Euphausia crystallorophias, which are dominant Antarctic krill, are major prey for most predators, such as fishes, birds, and marine mammals. An understanding of the feeding ecology of krill may provide the information for the structure and function of the Amundsen Sea ecosystem. Thus, we applied two biochemical approaches (fatty acids and stable isotopes) to determine the trophodynamics of adult krill in the Amundsen Sea. There were no significant differences in lipid contents between the two species, but the dominant storage lipids were different. Triacylglycerol (TAG) was dominant in E. superba, but wax esters (WE) were dominant in E. crystallorophias due to their different living strategies. Furthermore, the lipid content of E. crystallorophias displayed a spatial variation, being highest on the glacial edge. It was difficult to understand the feeding strategy and food source using only the fatty acid compositions of krill and in situ particulate organic matter. However, we found that specific FA ratios (18:1ω9/18:1ω7 and PUFA/SFA) and the nitrogen isotope ratio (δ15N) provide more insight into the feeding ecology of krill, such as feeding strategy and trophic position. These ratios suggest that E. crystallorophias consistently showed a higher degree of carnivorous feeding than E. superba in the Amundsen Sea during the austral summer. In conclusion, adult E. superba might more directly obtain their energy from in situ primary producers in the open sea, but, in the Amundsen Sea Polynya, adult E. crystallorophias seems to obtain their energy mainly through the microbial loop (microzooplankton). If so, E. crystallolophias would be a key player not only to transfer the energy from microbes to higher trophic levels but also to control the carbon and nitrogen cycle in the Amundsen Sea Polynya.

On-line stable isotope gas exchange reveals an inducible but leaky carbon concentrating mechanism in Nannochloropsis salina.

Carbon concentrating mechanisms (CCMs) are common among microalgae, but their regulation and even existence in some of the most promising biofuel production strains is poorly understood. This is partly because screening for new strains does not commonly include assessment of CCM function or regulation despite its fundamental role in primary carbon metabolism. In addition, the inducible nature of many microalgal CCMs means that environmental conditions should be considered when assessing CCM function and its potential impact on biofuels. In this study, we address the effect of environmental conditions by combining novel, high frequency, on-line (13)CO2 gas exchange screen with microscope-based lipid characterization to assess CCM function in Nannochloropsis salina and its interaction with lipid production. Regulation of CCM function was explored by changing the concentration of CO2 provided to continuous cultures in airlift bioreactors where cell density was kept constant across conditions by controlling the rate of media supply. Our isotopic gas exchange results were consistent with N. salina having an inducible "pump-leak" style CCM similar to that of Nannochloropsis gaditana. Though cells grew faster at high CO2 and had higher rates of net CO2 uptake, we did not observe significant differences in lipid content between conditions. Since the rate of CO2 supply was much higher for the high CO2 conditions, we calculated that growing cells bubbled with low CO2 is about 40% more efficient for carbon capture than bubbling with high CO2. We attribute this higher efficiency to the activity of a CCM under low CO2 conditions.

Intraspecific Differences in Lipid Content of Calanoid Copepods across Fine-Scale Depth Ranges within the Photic Layer

Copepods are among the most abundant and diverse groups of mesozooplankton in the world's oceans. Each species has a certain depth range within which different individuals (of the same life stage and sex) are found. Lipids are accumulated in many calanoid copepods for energy storage and reproduction. Lipid content in some species increases with depth, however studies so far focused mostly on temperate and high-latitude seasonal vertically migrating copepods and compared lipid contents among individuals either from coarse layers or between diapausing, deep-dwelling copepods and individuals found in the photic, near-surface layer. Here we examined whether lipid contents of individual calanoid copepods of the same species, life stage/sex differ between finer depth layers within the upper water column of subtropical and Arctic seas. A total of 6 calanoid species were collected from samples taken at precise depths within the photic layer in both cold eutrophic and warm oligotrophic environments using SCUBA diving, MOCNESS and Multinet. Measurements of lipid content were obtained from digitized photographs of the collected individuals. The results revealed significant differences in lipid content across depth differences as small as 12–15 meters for Mecynocera clausi C5 and Ctenocalanus vanus C5 (Red Sea), Clausocalanus furcatus males and two clausocalanid C5s (Mediterranean Sea), and Calanus glacialis C5 (Arctic). We suggest two possible explanations for the differences in lipid content with depth on such a fine scale: predator avoidance and buoyancy.

Comparison of Lipid and Calorie Loss From Donor Human Milk Among 3 Methods of Simulated Gavage Feeding

The objective of this study was to compare the differences in lipid loss from 24 samples of banked donor human milk (DHM) among 3 feeding methods: DHM given by syringe pump over 1 hour, 2 hours, and by bolus/gravity gavage. Comparative, descriptive. There were no human subjects. Twenty-four samples of 8 oz of DHM were divided into four 60-mL aliquots. Timed feedings were given by Medfusion 2001 syringe pumps with syringes connected to narrow-lumened extension sets designed for enteral feedings and connected to standard silastic enteral feeding tubes. Gravity feedings were given using the identical syringes connected to the same silastic feeding tubes. All aliquots were analyzed with the York Dairy Analyzer. Univariate repeated-measures analyses of variance were used for the omnibus testing for overall differences between the feeding methods. Lipid content expressed as grams per deciliter at the end of each feeding method was compared with the prefed control samples using the Dunnett's test. The Tukey correction was used for other pairwise multiple comparisons. The univariate repeated-measures analysis of variance conducted to test for overall differences between feeding methods showed a significant difference between the methods (F = 58.57, df = 3, 69, P < .0001). Post hoc analysis using the Dunnett's approach revealed that there was a significant difference in fat content between the control sample and the 1-hour and 2-hours feeding methods (P < .0001), but we did not find any significant difference in fat content between the control and the gravity feeding methods (P = .3296). Pairwise comparison using the Tukey correction revealed a significant difference between both gravity and 1-hour feeding methods (P < .0001), and gravity and 2-hour feeding method (P < .0001). There was no significant difference in lipid content between the 1-hour and 2-hour feeding methods (P = .2729). Unlike gravity feedings, the timed feedings resulted in a statistically significant loss of fat as compared with their controls. These findings should raise questions about how those infants in the neonatal intensive care unit are routinely gavage fed.

Lipid content and fatty acid composition in wild-caught silver pomfret ( Pampus argenteus) broodstocks: Effects on gonad development

The fatty acid reserves of broodstocks profoundly affect the fecundity of spawners as well as the quality of the newly hatched larvae. Investigation of the lipid and fatty acid changes in wild-caught broodstocks during the reproductive season should elucidate the most effective strategy with which to enrich broodstocks in artificial breeding programs. This paper investigated the lipid and fatty acid compositions of wild broodstocks of silver pomfret, Pampus argenteus, caught at the Zhoushan fishery ground during the reproductive season. The results indicated that there were significant differences in lipid content among gonad, muscle and liver; mean lipid levels in ovary, testis, liver and muscle were 41.85%, 18.54%, 27.80% and 32.31%, respectively. The lipid content in gonads at developmental stages III–V was relatively more stable than that in muscle or liver, although the lipid level increased in ovary and decreased in muscle as the female broodstocks developed from phase III to phase V. There were significant differences in fatty acid levels among broodstock ovary, testis, muscle and liver. The dominant fatty acids in ovary were as follows: 18:1n−9 (16.91%) > DHA (docosahexaenoic acid) (15.46%) > 16:4n−3 (13.14%) > 16:0 (12.65%) > EPA (eicosapentaenoic acid) (6.46%) > 16:1 (5.34%). In female broodstock liver and muscle, the dominant fatty acids were 16:0 (36.42%) > 18:1n−9 (23.26%) > 18:0 (7.50%) > 16:1 (6.98%) > 14:0 (5.10%) > DHA (4.98%) and 18:1n−9 (26.35%) > 16:0 (24.07%) > DHA (8.38%) > 16:1 (6.62%) > 18:0 (5.48%) > 14:0(4.44%), respectively. The dominant fatty acids in testis were as follows: DHA (29.84%) > 16:0 (23.93%) > 18:1n−9 (8.78%) > 18:0 (7.98%) > EPA (7.96%) > ARA (arachidonic acid) (3.24%). In the liver and muscle of male broodstocks, the dominant fatty acids were 16:0 (30.14%) > 18:1n−9 (25.54%) > 18:0 (8.24%) > 16:1 (7.24%) > 14:0 (5.20%) > DHA (4.75%) and 18:1n−9 (29.51%) > 16:0 (23.90%) > DHA (7.80%) > 18:0 (6.34%) > 16:1 (6.22%) > 14:0(3.88%), respectively. The n−3PUFAs and n−3/n−6 ratios in ovary and testis of the broodstocks were significant higher than those in the liver and muscle of the broodstocks. The changes in fatty acid composition in ovary and testis as the broodstocks developed from phase III to phase V were smaller in magnitude than those in muscle or liver. It is therefore suggested that the lipid preferentially transferred to ovary from muscle during the reproductive season, and the PUFAs, such as DHA, EPA, 16:4n−3 and ARA, were selectively transferred to, and conserved in, the ovaries of silver pomfret broodstocks.

Biochemical effects of three commercial formulations of Bacillus thuringiensis (Agerin, Dipel 2X and Dipel DF) on Spodoptera littoralis larvae

Effectiveness of commercialformulations of Bacillus thuringiensis var Kurstaki Agerin, Dipel 2X and Dipel on total protein and lipid contents were studied. Activities of detoxification and metabolic enzymes were also measured in treated and control larvae of cotton leafworm Spodoptera littoralis. Collected samples from treated larvae at intervals of 48 and 120 hrs post treatment were analyzed to assess the total protein and lipid contents as well as the enzymes activities. Significant reductions were observed in total protein content at 120 hrs larvae in all treatments compared with control. In all larvae treated with Agerin and Dipel DF the lipid content was significantly elevated after 48 and 120 hrs of treatment while Dipel 2X showed no significant difference in lipid content. However, fluctuated changes in the enzymes activity of treated larvae were found. We conclude that there are differences in biochemical effects between various commercial formulations of Bacillus thuringiensis kurstaki. In most cases Agerin was found more effective on S. littoralis than others.

RNA Interference‐based Suppression of Phosphoenolpyruvate Carboxylase Results in Susceptibility of Rapeseed to Osmotic Stress

The diverse functions of phosphoenolpyruvate carboxylase (PEPCase; EC 4.1.1.31) in C(3) plants are not as well understood as in C(4) plants. To investigate the functions of PEPCase in C(3) plants, rapeseed (Brassica napus L.) PEPCase gene (referred to as BNPE15) was silenced by the RNA interference (RNAi) technique. Under normal growth conditions, no significant difference in lipid content and fatty acid composition were found between wild-type (WT) and transgenic rapeseed plants. However, when these plants were subjected to osmotic stress induced by osmoticum polyethylene glycol (PEG-6000), membrane permeability and membrane lipid peroxidization in roots and leaves of transgenic plants were higher than those of WT plants. It suggested that transgenic plants are more susceptible to osmotic stress than WT plants. Taken together, the results showed that the suppression of PEPCase by RNAi leads to susceptibility to osmotic stress in rapeseed, and PEPCase is involved in the response of C(3) plants to environmental stress.

Morphology and total lipids in Thysanoessa macura from the southern part of the Indian Ocean during summer. Spatial and sex differences

Samples obtained during austral summer (February) were utilized to study the morphological differences of Thysanoessa macrura and the total lipid content, in relation to sex and geographic location. This species shows an evolution in morphometry, its carapace length increases slightly with sexual maturation, and its second thoracic leg becomes bigger and stronger, as well as its dactylus and especially the setae in the dactylus, which are stronger in a bigger animal allowing them to feed on other lipid-rich zooplankton. All these characteristics seem to support the hypothesis that animals change their diet during this period, allowing them to grow faster during summer, and accumulate lipids as a reserve material. This hypothesis is supported by a steeper slope in the length-weight regression during summer and an even steeper slope of the regression between carapace length and total lipids, especially adults. Great differences in lipid content were found between subadults and adults during this season, being higher in adults and, especially females. Lipids were higher in the northern stations in frontal area. A significant difference in lipid content was found among the stations sampled. Also a significant difference in lipid content was found between subadults, males and females. The species has a longer reproductive season than previously thought, which could depend on local conditions. Its development is accelerated during the summer bloom. Life history strategies of subadults and adults are apparently quite different, according to our lipid results and morphometrics data. Lipids reserves in subadults are not accumulated during summer, thus, T. macrura must accumulate massive amounts of lipids during autumn or late summer as a survival strategy of the species, as proposed for other species.

Morphological and biochemical differentiation in Antarctic krill

During the February 1981 cruise FIBEX MD-25 between 30–50°E and 61–64°S, hydrography showed the presence of two gyres, confirmed by the geostrophic circulation relative to 1000 m from Levitus climatology, at the borders of these gyres concentrations of highly morphologically differentiated krill were found. Gaussian component analysis of krill samples, pooled by sectors, showed three cohorts of Euphausia superba in the western sector and one in the eastern sector. Across the sampling area, Thysanoessa macrura and E. superba occurred at separate stations. Analysis of cohorts in T. macrura separated two size groups in both the western and the eastern sectors. The use of a Differentiation Index (D.I.) [Färber-Lorda, J., 1990. Somatic length relationships and ontogenetic morphometric differentiation of Euphausia superba and Thysanoessa macrura of the southwest Indian Ocean during summer (February 1981). Deep-Sea Res. 37, 1135–1143.], based on somatic lengths, allows studying certain morphological differences within the populations sampled. Morphologically different and bigger males II (D.I. from 2.8 to 3.5) were present only in the southern transect while smaller males I (D.I. from 3.5 to 5.0) were present over the entire area. Biochemical composition of both species showed significant differences among stations for protein, lipids, and carbohydrates. A significant difference in lipid content was found between males I, and males II. For T. macrura, percentage of lipid content in mature animals was much higher than that in E. superba. The D.I. size distribution showed that when populations of E. superba were highly differentiated (corresponding to mature animals) in morphology, lipid content was high, and they were located near a gyre. Differences in morphometry can influence distribution of the species, because different developing stages have different swimming capacities. It is shown that, together with hydrography and trophic conditions, lipid content and morphometry of krill populations, are different but complementary aspects that help to understand krill ecology and distribution.

The Metarhizium anisopliae Perilipin Homolog MPL1 Regulates Lipid Metabolism, Appressorial Turgor Pressure, and Virulence

Cells store lipids in droplets. Studies addressing how mammals control lipid-based energy homeostasis have implicated proteins of the PAT domain family, such as perilipin that surrounds the lipid droplets. Perilipin knock-out mice are lean and resistant to obesity. Factors that mediate lipid storage in fungi are still unknown. Here we describe a gene (Mpl1) in the economically important insect fungal pathogen Metarhizium anisopliae that has structural similarities to mammalian perilipins. Consistent with a role in lipid storage, Mpl1 is predominantly expressed when M. anisopliae is engaged in accumulating lipids and ectopically expressed green fluorescent protein-tagged MPL1 (Metarhizium perilipin-like protein) localized to lipid droplets. Mutant M. anisopliae lacking MPL1 have thinner hyphae, fewer lipid droplets, particularly in appressoria (specialized infection structures at the end of germ tubes), and a decrease in total lipids. Mpl1 therefore acts in a perilipin-like manner suggesting an evolutionary conserved function in lipid metabolism. However, reflecting general differences between animal and fungal lineages, these proteins have also been selected to cope with different tasks. Thus, turgor generation by DeltaMpl1 appressoria is dramatically reduced indicating that lipid droplets are required for solute accumulation. This was linked with the reduced ability to breach insect cuticle so that Mpl1 is a pathogenicity determinant. Blast searches of fungal genomes revealed that perilipin homologs are found only in pezizomycotinal ascomycetes and occur as single copy genes. Expression of Mpl1 in yeast cells, a fungus that lacks a perilipin-like gene, blocked their ability to mobilize lipids during starvation conditions.

Effects of dietary lipid sources on growth and fatty acid composition of juvenile shrimp, Litopenaeus vannamei

This experiment was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid (FA) composition of juvenile shrimp, Litopenaeus vannamei. Six isoenergetic and isonitrogenous semi-purified diets containing casein, solvent-extracted soybean meal and gelatin as protein sources, were supplemented with 60 g kg−1 of lipid sources. The lipid sources included: pollack fish oil (PO), pork lard (PL), soy oil (SO), peanut oil (PN), rapeseed oil (RO) and a mixture of pollack fish oil and soy oil (POSO 1 : 1 w/w). Each diet was fed to juvenile shrimp (0.10 g average weight) four times daily in triplicate tanks to apparent satiation (feeding ratio was about 8%) for 8 weeks. At the end of the experiment, weight gain, specific growth rate and protein efficiency ratio were significantly higher for shrimp fed the diet containing PO and the POSO mixture oil than the other lipid sources. The nutritional values of SO, RO, PN and PL were similar. Shrimp fed on PO, mixture oil of POSO and SO had better survival rates than the other lipid sources, and shrimp fed the PL had the lowest survival rate. There were significant differences in lipid contents of whole body and hepatopancreas amongst the dietary treatments; however, lipid contents of tail muscle were not significantly affected by the dietary lipid sources. Shrimps fed POSO diet had higher protein content in whole body than those fed the other lipid sources, and shrimp fed PO diet had highest crude protein content of the tail muscle. A high correlation was found between dietary FA composition and FA composition of whole shrimp. FA composition of the whole body was generally affected by dietary lipid sources, especially dietary unsaturated FA.

Effects of geographic source, rearing system, and season on the nutritional quality of wild and farmed Perca fluviatilis

The effects of season, geographic source (Lake Geneva, Rhine River), and rearing system (extensive, semiextensive, and intensive systems) on the lipid content and FA composition of fillets of Perca fluviatilis were studied. Significant differences in the total lipid content were found between fish coming from the Rhine River and Lake Geneva (1.21 and 1.48%, respectively). Seasonal effects were investigated quarterly for perch sampled in the Rhine River. Intensively reared perch displayed a higher lipid content (1.48%) than the other farmed perch, i.e., 1.26% for a semiextensive system and 1.16% for an extensive system. No significant difference in lipid content was found (i) between lacustrine fish and intensively reared fish or (ii) among fish from the Rhine River and the semiextensive or extensive rearing systems. The main FA were 22:6n-3 (DHA, 21.3-37.1% of total FA), 16:0 (17.7-20.2%), 20:5n-3 (EPA, 9.2-13.2%), 18:1 (8.0-11.5%), 20:4n-6 [arachidonic acid (ARA), 1.9-10.7%], 16:1 (4.3-6.0%), and 18:2n-6 (2.1-6.0%). In comparison with perch coming from the Rhine River, the lacustrine fish were characterized by higher total n-6 PUFA and a lower proportion of both total monounsaturated FA (MUFA) and total n-3 PUFA. Among rearing systems, extensively farmed fish had higher n-6 PUFA and lower n-3 PUFA contents. Wild fish showed higher ARA and 18:2n-6 than farmed fish. They also had significantly more EPA (12.5-13.2%) than farmed perch (9.2-10.9%). For DHA, no difference existed between (i) the lacustrine fish (31.9% of total FA) and the intensively reared fish (33.0%) and (ii) the Rhine (37.1%) and semiextensively reared fish (36%). Effects of size, diet composition, and environmental conditions on the total lipid contents and FA composition are discussed.

Growth, oxygen consumption, ammonia-N excretion, biochemical composition and energy content of Farfantepenaeus paulensis Pérez-Farfante (Crustacea, Decapoda, Penaeidae) early postlarvae in different salinities

Physiological responses of early postlarval shrimp Farfantepenaeus paulensis to different salinities were evaluated. Growth, net growth efficiency ( K 2), oxygen consumption, ammonia-N excretion, protein, lipid, carbohydrate, ash and energy content were determined in postlarval stages PL VI–VII and PL XIII–XV at 5‰, 15‰, 25‰ and 34‰. PL VI–VII and PL XIII–XV correspond, in the wild, to the penetration of postlarvae into estuarine zones and the adoption of benthic habits, respectively. Postlarvae were gradually acclimated to the various salinity levels in the stage PL VI–VII and were maintained there until reaching the stage PL XIII–XV. Although development time was not affected by salinity, growth was decreased at 34‰. Oxygen consumption was less affected by salinity while ammonia-N excretion presented a negative correlation with salinity. In both stages, protein content was lower at 34‰. In PL VI–VII, lipid was decreased at 5‰, while no significant difference in lipid content was observed in PL XIII–XV. Carbohydrate and ash levels did not vary in function of salinity levels. Energy content was reduced in PL XIII–XV at 34‰. Net growth efficiency ( K 2) between PL VI–VII and PL XIII–XV presented higher values at 15‰ and 25‰, and the lowest at 34‰. Enhanced energy expenditure due to osmoregulation was not detected as denoted by oxygen consumption rates. Nitrogen metabolism seems to play a key role in maintaining body fluids concentration in relation to medium salinity. It is concluded that the high degree of euryhalinity in these stages of F. paulensis may be an adaptation to ontogenetic events such as migration to estuarine areas. For aquaculture purposes, it is recommended to maintain these postlarval stages at salinities between 15‰ and 25‰ rather than 34‰.

Isolation and Physicochemical Characterization of Fonio (Digitaria exilis Stapf) Starch

AbstractFonio (Digitaria exilis Stapf) starch was isolated from the seeds of two varieties denominated Hothia and Koulli and its physicochemical properties were compared with those of commercial wheat starch. Fonio starch granules seen under a SEM had polygonal shapes and small size (about 8μm). Amylose content of Hothia (22.6%) was significantly lower than that of Koulli and wheat (26.1% and 25.0%, respectively). there was not any significant difference in lipid content of fonio starches (2.8% and 2.9%), whereas significant differences were observed in their water binding capacity (88% and 80%). Protein and ash were also determined. The swelling power and solubility of wheat and fonio starches within the 50°C‐90°C temperature range were also studied. Brabender amylograms of 5% fonio starch slurries showed similarly shaped, single‐step curves. However, the two fonio varieties reached quite different viscosity values during the heating and cooling cycle.

Bright yellow chlorosis by cucumber mosaic virus Y satellite RNA is specifically induced without severe chloroplast damage

We have analysed morphological and physiological changes of the chloroplasts in tobacco plants infected with cucumber mosaic virus (CMV) Y satellite RNA (Y-satRNA). The infected tissues were bright yellow. Although the chlorophyll content of the tobacco plants infected with CMV-O + Y-satRNA was reduced to one-third to one-quarter of that of CMV infected and healthy tobacco plants, the chloroplasts in the Y-satRNA-infected leaves were ultrastructurally similar to those in the plants infected with only CMV-O. There were no significant differences in lipid content or composition of the chloroplast membrane between Y-satRNA-infected and CMV-O infected leaves. While the levels of all the stroma proteins were equivalent, the overall thylakoid proteins were decreased in the Y-satRNA-infected tissue compared with the CMV infected tissue. Chlorosis induced by Y-satRNA appears to result in the reduction of the chlorophyll-binding proteins. However, the photosynthetic ability of the chloroplasts from Y-satRNA infected leaves was greater than that of chloroplasts from CMV-O infected leaves. The possibility that chlorosis induced by Y-satRNA may be due to specific inhibition of chlorophyll accumulation rather than to chloroplast degradation is discussed in this paper.