High Amounts Of Lipids Research Articles

Optimization and validation of solvent and supercritical-fluid extractions for the trace-determination of polycyclic aromatic hydrocarbons in sewage sludges by liquid chromatography coupled to diode-array and fluorescence detection

There is a need for a better characterization of sludges from wastewater treatment plants which are destined to be spread on agricultural land. Inorganic pollutants are regularly controlled, but organic pollutants have received little attention up to now. The main problem for trace analysis of organic pollutants comes from the complexity of the various matrices of sludges, which depends on their origins. Therefore, methods described for soils and sediments cannot be directly applied to sludges which contain high amount of lipids. This paper provides a method for trace-determination of polycyclic aromatic hydrocarbons in the range of mg/kg of dried sludge including an extraction step, and an analysis step by liquid chromatography with fluorescence detection for sensitive quantification and UV–diode-array detection for confirmation. The extraction step was optimized by a selection of the solvent used for both Soxhlet and supercritical-fluid extraction and by setting the experimental conditions (temperature, pressure, modifier, etc.) used for SFE. Extraction recoveries were found similar and quantitative for the two procedures. However supercritical-fluid extraction appears to be a good alternative to Soxhlet extraction because of the consumption of less time and solvent. Detection limits were obtained in the range of 0.1–1 mg/kg of dried sludges, with possible confirmation by UV spectra. The whole method (extraction/quantification/confirmation) was validated using sludges which have been certified by the Community Bureau of Reference from Brussels (CRM No. 088). Application to the determination of PAHs in urban sludges is presented.

Chemical contents of Macaranga food bodies: adaptations to their role in ant attraction and nutrition

1. Macaranga (Euphorbiaceae) is a paleotropical tree genus comprising myrmecophytic and non‐myrmecophytic species. All species are presumed to possess food bodies (FBs) to maintain or attract ants as anti‐herbivore defence. 2. The hypothesis was tested that Macaranga species differing in their mode of association with ants would produce FBs differing in their chemical composition. We investigated contents of carbohydrates, proteins and lipids in FBs of four myrmecophytic and one non‐myrmecophytic Macaranga as well as one Parthenocissus (Vitaceae) species. 3. On a dry weight basis, FBs of myrmecophytes contained relatively higher amounts of proteins compared to carbohydrates than those of non‐myrmecophytes. Soluble carbohydrates showed species‐specific patterns and were found in especially high amounts in both non‐myrmecophytes. Furthermore, Parthenocissus FBs contained higher amounts of soluble compared to polymerous substances not only in carbohydrates but also in proteins. 4. FBs seem to be specifically adapted to their respective role in ant attraction and nutrition, with myrmecophytes providing ants with high amounts of lipids and proteins and non‐myrmecophytes mainly offering carbohydrates in the form of common soluble sugars.

The improved incorporation of polyunsaturated fatty acids and changes in liver structure in larval gilthead seabream fed on microdiets

Two feeding experiments were conducted to evaluate the suitability of two commercial microdiets as a complementary food for the rearing of larval gilthead seabream Sparus aurata. The effect of these diets on growth, survival and total lipid composition, as well as the histological structure of the liver were examined. The results of the first trial highlighted water quality as an important factor for the survival of microdiet‐fed larvae. An increase in water flow rate improved larval survival despite a reduction in live food supply. An effect of tank design on larval growth and survival was observed also and seems to be related with the light level inside the tanks; wider light grey tanks gave better results than narrower black ones. Microdiet feeding significantly improved larval growth and increased hepatocyte diameter and presence of PAS positive vacuoles suggesting an increased glycogen storage in comparison with that of larvae fed live prey only. Artificial diets provided the larvae with a higher amount of lipids and polyunsaturated fatty acids of the n‐3 series, resulting in a higher DHA content in the total lipid of the larvae fed on microdiets.

SEA‐BUCKTHORN LIPIDS

ABSTRACTIn contrast to other berry fruits in which lipids occur only in seeds, lipids in sea‐buckthorn berries were distributed in the rind, flesh, and seeds. Over 70% lipids occurred in the free form while the rest occurred in the bound form. There were substantial differences in the amount of lipids in the particular morphological parts of the fruit. The flesh contained the highest amount of lipids and the seeds had the lowest. Over 97% of flesh lipids, 92% of seed lipids, and 91% of rind lipids were in the neutral form, with the remainder being polar lipids. The fatty acid compositions of flesh and rind lipids were predominated by the C16:0, C16:1, and C18:2 fatty acids. Predominant fatty acids in the seed lipids were C18:1 and C18:2.

Lipid production by Monascus purpureus albino strain

Monascus purpureus DSM 1379 strain was used to study pigment and lipid synthesis and it was shown that both processes are concurrent. In order to obtain only lipids a white mutant has been selected from the red pigment producing strain. This stable mutant lost its ability to produce pigments and revealed morphological and biochemical differences compared to the parent strain. Kinetics of the lipid biosynthesis of the albino mutant in submerged cultures have been studied at C/N ratios of 10:1 and 80:1. The estimation of the specific rates of glucose and nitrogen consumption along with the lipid production indicated more efficient lipid synthesis at C/N ratio 80:1, i.e. 72% (w/w) against 43% (w/w) for C/N ratio 10:1. The neutral, phospho- and glycolipid composition was not influenced by the C/N ratio and nitrogen source used. The investigation of the fatty acid content showed that the major fatty acids were C 18:1 (45.5%), and C 16 (22.1%). The selected mutant is able to produce high amount of lipids consisting of 88% triglycerides with a percentage of saturated fatty acids 51%.

Seasonal Changes in Carbohydrates, Lipids and Fatty Acids of Two Mediterranean Dimorphic Phrygana Species

Summary Storage patterns of soluble sugars, starch, lipids and fatty acids were investigated in leaves, stems and roots of Euphorbia acanthothamnos and Phlomis fruticosa throughout a year. Winter leaves of both species contained higher amounts of lipids than summer leaves. Leaf soluble sugar content showed two peaks (winter and summer) in P. fruticosa and a winter peak in E. acanthothamnos. Starch was mainly accumulated in young expanding winter- and summer-leaves and depleted twice over the year, during the cold winter and the drought summer, respectively. Considering stems and roots, storage substances exhibited identical fluctuations, i.e. the maximum values of lipids being recorded during winter and those of starch during spring. The molar quotient (MQ) of polyunsaturated to saturated fatty acids was low, mainly due to the high percentage of palmitic acid in all tissues of both examined species. Nevertheless, roots exhibited a different fatty acid composition than the above ground parts of the plants. The energy content of storage substances (ECS) was mainly contributed by lipids and the minimum values in both species were recorded during drought. On the basis of seasonal variation of ECS, dimorphic phrygana can be situated between mediterranean evergreen sclerophylls and central european evergreen conifers. It was presumed that in the case of dimorphic phrygana, summer seems to be a dormant period, whereas winter the investive period.

Ultrastructural and histochemical characterization of marmoset (Callithrix jacchus) Leydig cells during postnatal development

Leydig cell development was investigated in the marmoset (Callithrix jacchus) testis from 24 h post partum (pp) up to sexual maturity, using ultrastructural and histochemical methods. Electron microscopically three different Leydig cell (LC) types could be distinguished: neonatal, immature and adult LCs. Neonatal LCs exhibited a round nucleus, large tubular mitochondria, abundant smooth endoplasmic reticulum (SER), and few small fat vesicles. The typical immature LCs showed a lobulated nucleus, smaller tubulo-vesicular mitochondria, less SER, and larger fat vesicles. Adult LCs contained an invaginated nucleus, tubular mitochondria, abundant SER, large fat vesicles, and lipofuscin granules. Neonatal Leydig cells occurred from 24 h pp up to 10 weeks pp, immature LCs from 2 weeks pp up to 20 weeks pp, and adult LCs from 20 weeks onwards. The appearance of a new LC population was accompanied by a numeric decrease and occurrence of regressive cells of the previous population. Developmental steps of differentiation were recognizable in the population of immature and adult LCs by the amount of SER (immature LCs), the size of mitochondria (adult LCs), and the morphology of the nucleus at the beginning of their appearance. Activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) was moderate in immature LCs from 2 weeks pp to 12 weeks pp and strong in adult LCs. Neonatal LCs were not stained nor were immature LCs from 16 weeks to 20 weeks. Comparison of the ultrastructural classification of LCs and the activity of 3 beta-HSD showed that the capacity for steroid biosynthesis does not necessarily include morphological differences. Activity of non-specific esterase (nE) was found in LCs except of the period between 16 and 25 weeks pp. A transient decrease of activity was seen during the first week of life. Both, the phase of decrease and the phase of inactivity were followed by distinct activation of nE. Lipid content and the size of single fat droplets in LCs, as seen with Sudan black staining, varied during postnatal development. Finely stained granules were typical for neonatal LCs, whereas larger droplets were found in immature and adult cells. Particularly high amounts of lipids were seen at one week and between 32-60 weeks pp, which was the regression of neonatal LCs, showing ultrastructurally higher amounts of lipids than intact neonatal LCs. High amounts of lipid during puberty (32-60 weeks pp) accompanied by an activation of nE at the onset of puberty suggest an initiative role in steroidogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Isolation and characterization of fatty acid auxotrophs from the oleaginous yeast Apiotrichum curvatum

In order to improve the economic value of lipids produced by the oleaginous yeast strain Apiotrichum curvatum ATCC 20509, a search was made for mutants defective in the conversion of stearic acid to oleic acid. Mutants could be selected as unsaturated fatty acid auxotrophs, since unsaturated fatty acids are essential componenets in membrane lipids. After treatment of A. curvatum wild-type with N-methyl-N′-nitro-N⇔-nitrosoguanidine, 58 fatty-acid-requiring mutants were isolated. On the basis of (1) the growth response to saturated and unsaturated fatty acids and (2) the fatty acid composition of lipids produced by these mutants, it was concluded that only 18 of them were real unsaturated fatty acid (Ufa) mutants, while the other 40 were designated as fatty acid synthetase (Fas) mutants. It is further shown that Ufa mutants of A. curvatum are able to produce high amounts of lipids consisting of more than 90% triacylglycerols with a percentage of saturated fatty acids resembling that of cocoa butter, when grown in the presence of relatively small amounts of oleic acid in the growth medium. This may offer an economically favourable alternative in comparison with other methods that have been developed for the production of cocoa butter equivalents by microorganisms.

Level and composition of wax esters in the different tissues of deep-sea teleost fish Laemonema longipes.

The lipid class compositions of different tissues of the deep-sea teleost fish Laemonema longipes from the northwestern Pacific Ocean were investigated. The liver of this species was found to contain a remarkably high amount of lipids, which were characterized by high quantities of wax esters and a low proportion of triglycerides. Conversely, the flesh and ovary lipids were low in the above lipid types but high in phospholipids. The wax esters of liver lipids were found to consist mostly of C38, C40, C42 and C36 components for the carbon chain length. The principal fatty alcohol moieties of liver wax esters were: 22:1, 20:1 and 16:0, which were very similar in composition to those isolated from total lipids of the flesh and ovary. On the other hand, the fatty acids of liver wax esters contained a high percentage of monoenes, consisting of 18:1, 16:1, 20:1 and 22:1 acids, and a significant amount of polyenes, particularly 20:5 ω 3 acid. The fatty alcohol/fatty acid combination of the L. longipes liver wax esters was supported by the assumption of a random fashion; the relationship between the calculated and experimentally found wax esters based on carbon chain lengths was very close in composition.

The production of tumor necrosis factor by mouse bone marrow-derived macrophages in response to bacterial lipopolysaccharide and a chemically synthesized monosaccharide precursor.

Lipid X, a monosaccharide biosynthetic precursor of lipid A, has been chemically synthesized and was shown to induce bone marrow-derived macrophages to release tumor necrosis factor (TNF) in vitro. However, relatively high amounts of lipid X were necessary for induction, and the levels of TNF were much less than those induced by small amounts of lipid A itself or LPS. Lipid X prepared by extraction of Escherichia coli mutants induced higher levels of TNF than the chemically synthesized material, but this is probably partially due to amounts of impurities in the extracted material. Pretreatment of macrophages with IFN-gamma resulted in the release of higher amounts of TNF on subsequent induction with either LPS or lipid X. In contrast, pretreatment of macrophages with LPS induced hyporesponsiveness for TNF production on subsequent rechallenge with LPS. Lipid X, on the other hand, was incapable of making macrophages hyporesponsive for TNF production.

Bitter Almond, Plum and Mango Kernels as Sources of Lipids

AbstractThe chemical composition of bitter almond, plum and mango kernels and the physico‐chemical characteristics of their lipids were studied. Bitter almond and plum kernels contained higher amounts of lipids in comparison to mango kernels. All kernel lipids were found free from hydrocyanic acid. The predominant lipid class of the studied kernel lipids was triglycerides. Oleic acid was the major fatty acid present in bitter almond and plum kernel lipids, while mango kernel lipids were rich in stearic and oleic acid.

Distribution of diacyl glyceryl ethers in the different tissues and stomach contents of gonatid squid Berryteuthis magister.

The lipid class compositions of the different tissues and stomach contents of the gonatid squids Berryteuthis magister from the northwest Pacific were investigated. In this species, the liver contained a remarkably high amount of lipids, which were characterized by high percentage of diacyl glyceryl ethers and triglycerides. On the contrary, the lipids of the mantle, ovary and stomach contents were low in the above types of lipids but high in phospholipids. Besides this, the stomach content lipids also consisted of large amounts of wax esters. Alkyl glyceryl ethers originated from diacyl glyceryl ethers of the examined tissues and stomach contents were very similar in composition; the most abundant component was chimyl alcohol followed by selachyl alcohol. Of the stomach content lipids, fatty alcohols derived from the wax ester were constituted mainly of 16:0, 18:1, 20:1 and 22:1 alcohols. Differences were found in the percentageof the component fatty acids of the total lipids among the examined tissues and stomach contents. It was found that the diacyl glyceryl ethers were in an unusually high concentration in the livers at various growth stages of B. magister studied. Thus it was postulated that these ether-linked lipids are probably biosynthesized via some of the dietary fatty alcohols, which would be a possible origin of the alkyl moiety of the compounds, rather than as a direct accumulation from dietary sources.

Composition and metabolism of lipids in some tissues of the mussel Mytilus galloprovincialis L. (Moll. bivalvia)— in vivo and in vitro incorporation of 1(3)-[ 3H]-glycerol

1. 1. In mussel, just before spawning, the digestive gland contains higher amounts of lipids, mainly triglycerides. The digestive gland phospholipids have the higher percentage of phosphatidylcholine and the lowest percentage of phosphatidylethanolamine followed by the mantle and the gills. 2. 2. In vivo studies of the 1(3)-[ 3H]-glycerol incorporation shows an equal distribution of the radioactivity between neutral and phospholipids for all tissues. The majority of radioactivity is incorporated in the mantle. The specific radioactivity of the triglycerides and diglycerides is highest in the gills followed by the mantle. The mantle phosphatidylcholine and phosphatidylinositol have the faster turnover. 3. 3. In vitro incorporation of [ 3H]-glycerol in mantle lipids give rise to a pattern of radioactivity distribution similar to the in vivo situation.

N-demethylation of p-chloro- N-methylaniline catalyzed by subcellular fractions from the avocado pear ( Persea americana)

Subcellular fractions from the avocado pear ( Persea americana) catalyzed formation of p-chloroaniline from p-chloro- N-methylaniline. Fractions prepared by centrifugation of avocado homogenates at 20,000 g for 20 min formed p-chloroaniline (2900 ± 500 pmol min −1 mg protein −1) with an NADPH-generating system. p-Chloroaniline formation required reduced pyridine nucleotide (NADPH was 6–7 times more effective than NADH) and O 2. N-Demethylation was inhibited by CO (55% inhibition at CO:O 2 = 1) and was not inhibited by CN. Cytochrome P-450 was detected in the 20,000 g pellet at levels of 300–380 pmol/mg protein. This particulate preparation was also active in catalyzing the NADPH-dependent epoxidation of the chlorinated cyclodiene aldrin. Improvements to a colorimetric procedure for measuring p-chloroaniline increased the sensitivity of the procedure fourfold, and allowed use of samples containing high amounts of lipid. Avocado pear is suitable tissue for further studies on the oxidation of foreign compounds by higher plants.

Physicochemical Changes Produced in Egg Yolk by Streptococcus faecalis var. liquefaciens

The growth of Streptococcus faecalis var. liquefaciens in sterile liquid egg yolk for 48 hr at 25 C resulted in the separation of the homogeneous yolk into two components, which appeared as layers. The upper layer is clear, oily, and has a higher amount of lipids and cholesterol as compared to the viscous lower layer, which contains greater quantities of protein, phosphorus, calcium, and iron. This separation is related to the production of an extracellular factor, probably a protease, which because of limited proteolysis causes destabilization of the egg yolk system. This destabilization results in, or is due to, aggregation of the granules, which because of size, weight, and compositional differences, settled to constitute the lower layer. Evidently, these granules are responsible for opacity, as the yolk devoid of this settled material is clear and makes up the upper layer.

Comparative physiological studies of Candida spec. H and its mutant H 13 during nitrogen starvation

With Candida spec. H and the mutant H13 during nitrogen starvation we studied the changes occurring in the macromolecular cell composition. In the absence of nitrogen, but in the presence of n-alkanes as carbon source, both the nucleic acid and protein levels of the dried yeasts rapidly decreased. At the same time carbohydrates and lipids were accumulated. Candida spec. H predominantly increased carbohydrate content, whereas the mutant accumulated significantly higher amounts of lipids. The main components of the cellular carbohydrates and the fatty acid content were analyzed, and the results were discussed.

Changes in the structure, composition and function of sarcoplasmic-reticulum membrane during development.

The structure, chemical composition and function of the microsomal fraction, isolated by differential centrifugation and purified on sucrose gradients, from muscle of fetal, newborn and young rabbits were characterized and compared with those of sarcoplasmic reticulum vesicles from adult muscle. Negative staining shows that the microsomal vesicles isolated from muscles of embryos and newborn animals are smooth, in contrast to vesicles obtained from adult muscle which contain 4-nm particles on their surface. The particles appear first in the microsomal vesicles from muscles of 5--8-day-old rabbits. Their number increases with the age of the animals. Ca2+-pump protein, with molecular weight about 100000, accounts for 10% of the total protein content in sarcoplasmic reticulum membrane, isolated at the earliest stages of development analysed. Its amount increases continuously with the rabbit's age to the adult value of about 70% of total sarcoplasmic reticulum protein. The low amount of 100000-dalton protein and lack of 4-nm surface particles in sarcoplasmic reticulum vesicles obtained from fetal and newborn rabbits are strictly correlated with the low activity of Ca2+-dependent ATPase and the ability to take up Ca2+. These activities rise in parallel with the age of the rabbits. On the other hand, Mg2+-dependent ATPase activity is very high at the early stages of development and declines continuously to a low value in sarcoplasmic reticulum from adult muscle. The sarcoplasmic reticulum membrane from fetal and newborn rabbits contains a higher amount of lipids as compared with the membrane present in the muscle of adult animals. The ratio of both phospholipid to protein and neutral lipid to protein decreases with the age of the rabbits. The composition of sarcoplasmic reticulum phospholipids also changes during development.

Studies on the Lipids of Micronektonic Fishes caught in Sagami and Suruga Bays, with Special Reference to Their Wax Esters

Following to the previous studies on micronektonic fishes in Sagami and Suruga Bays, five species of micronektonic shrimps, Acanthephyra quadrispinosa (A), Sergestes prehensilis (B), Sergestes lucens (C), Gennadas sp. (D) and Bentheogennema borealis (E), belonging to the order Decapoda were investigated. Most of them were not previously analyzed. Four species except for C show brilliant-reddish-natural carapace color. They live in the meso- and bathypelagic zones and undertake diel vertical migration as the micronektonic fishes do. These specimens were collected from surface to about 2000m depths in Sagami and Suruga Bays by ORI-plankton net and Isaacs-Kidd midwater trawl at night.The lipid contents of the micronektonic shrimps on the wet weight basis were 1.7% in C, the least value of all, and about a few per cent in A and B, and over 10% in D and E. Their lipids had 17.9% wax esters in C, around 30% in A and B, and more than 60% in D and E. As the representative examples of micronektonic shrimps, A and E were chosen and their viscera, muscle and carapace lipids were analyzed. The viscera contained the highest amounts of lipids (32.0% in A and 61.2% in E), however, the wax ester contents were almost equal even in the different tissue lipids of same specy.The wax esters cover the range from C30 to C46 with exceptional C which has rather shorter range. The major esters are C34, C36, C38, C40, C42, and C44, and also a trace amounts of odd numbered esters exist. Since the acid moiety of wax esters is dominantly monoenoic and docosahexaenoic acids and the alcohol moiety consists mainly of C16 : 0, C20 : 1 and C22 : 1, the combined wax esters range rathers longer esters. The fatty acid composition of triglycerides shows less highly unsaturated fatty acids, while that of free fatty acids reveals rather larger amounts of them, and fur thermore that of phospholipids contains the largest amounts of docosahexaenoic acid (4749%).Finally the importance of such studies on the micronekton was discussed and emphasized from the stand-points of food hygiene as well as of exploitation of marine resources, because the micronektonic fishes and shrimps rich in the wax esters would be mixed in the capture as the fishing grounds extend from horizontal to vertical directions.

On the phospholipids of Culex pipiens fatigans.

AbstractThe lipids of different developmental stages ofCulex pipiens fatigans, vector of bancroftian filariasis, have been investigated. The phospholipid composition of the developmental stages and of the subcellular fractions of fourth instar larvae of the insects were analyzed. The composition of fatty acids and their positional distribution have also been examined in the major phospholipids of the larvae. The insect eggs contained higher amounts of lipids than larvae suggesting that they were utilized during embryogenesis. Phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) comprised over 75% of the insect phospholipids. Of these, PE was present in the greatest amounts during all stages of growth and in the subcellular fractions of larvae. An ethanolamine containing sphingolipid was found as a component of the phospholipids of the insects. About 50% of the lipids of the larvae were localized in the cell debris and nuclei fraction which also contained most of the lysolipids of the insects. As in other Diptera 16∶0, 16∶1 and 18∶1 were the major fatty acids present in the insect lipids of which the fatty acid found in greatest amounts was 16∶1. Similar to the phospholipids of animal species, saturated fatty acids were predominantly linked to the 1 position of the major phospholipids of the insects while the unsaturated fatty acids were in higher amounts at the 2 position.

Enzyme Activities and Degradation of Nutrients in Chickpea (<i>Cicer arietinum</i> L.) Seeds during Germination

BARI-3 varieties of chickpea (Cicer arietinum L.) seed at different germinating periods. Among the varieties, the highest amylase activity was found in BARI-2 and lowest in BARI-3 during germination at 45 hours in water. The maximum activity of invertase was found in BARI-2 and minimum in BARI-1 at 72 hours of germination. Lipase activity was highest in BARI-2 and lowest in BARI-1. The highest protease activity was found in BARI-2 and lowest in BARI-3. The amount of total protein and water-soluble protein were found to be highest in BARI-1 and BARI-3, respectively. During light germination, carbohydrate depletion starts after initial imbibitions, and was completed in 120-144 hours. The variety BARI-1 was found to contain the highest amount of free sugar while BARI-3 had the lowest amount. BARI-2 was found to contain highest amount of reducing sugar and BARI-1 contained the lowest amount. The highest amount of starch was found in BARI-3 and lowest in BARI-1. The starch content in chickpea seed decreased gradually during germination. Among the varieties, BARI-1 was found to contain the highest amount of lipid while BARI-3 contained the lowest amount. The seed storage substances were found to decrease gradually with the increase of germination time. The results indicate that degradation of reserve seed nutrients accelerate the development of seedling growth during germination. Key words: Chickpea (Cicer arietinum L.) seed, Carbohydrate, Protein, Lipid, Hydrolytic Enzymes. DOI:10.3329/jbs.v16i0.3738 J. bio-sci. 16: 29-34, 2008