Effect of growth temperature on lipid composition of Streptococcus faecium

The effect of growth temperature on the lipid and fatty acid composition of Streptococcus faecium has been studied. No differences in the qualitative composition of S. faecium lipids were observed. In all isolated fractions (neutral lipids, glycolipids, and phospholipids plus other polar lipids), the major fatty acids were palmitic (C-16:0), palmitoleic (C-16:1), octadecenoic (C-18:1), and cyclopropane (C-19:0). Changes in the fatty acid composition of the different fractions were observed which depended on growth temperature; the most significant one was the decrease of octadecenoic acid and the increase of palmitic acid in glycolipids and polar lipids as the temperature increased. The level of cyclopropane C-19:0 was approximately eightfold lower at 8 degrees C than at the other temperatures tested (20, 30, and 45 degrees C).     

Fatty acids from 11 marine macroalgae of the French Brittany coast

Four species of red marine algae (Rhodophyceae), five species of brown marine algae (Pheophyceae) and two species of green marine algae (Chlorophyceae) were examined for the fatty acid composition of the three lipid groups separated by silica gel column chromatography (neutral lipids, glycolipids, phospholipids). The four red algae had high contents of 16:0 and C20-polyunsaturated fatty acids (PUFA), 20:5n-3 ranging from 18 to 49% of the total fatty acid content and 20:4n-6 from 1.4 to 22.5%, these fatty acids were evenly distributed in all lipid groups. The five brown algae had high contents of 18:1n-9, 18:2n-6 and 18:3n-3 but low content of 20:5n-3. No precise trend was detected for the distribution of these fatty acids in the three lipid groups. The two green algae had high contents of 16:0, 18:1n-7 and 18:3n-3 and a very low content of PUFA. They contained also large amounts of 16:4n-3 together with 16:2n-6 and 16:3n-3. While 16:2n-6 was mainly found in phospholipids, 16:4n-3 was mainly distributed in neutral lipids and glycolipids.Porphyra umbilicalis represents the richest source of 20:5n-3 whileUndaria pinnatifida can be selected when a balanced mixture of (n-6) and (n-3) PUFA is required.Author for correspondence     

Occurrence of long-chain fatty acids and glycolipids in the cell-envelope fractions of baker''s yeast

1. The total yield of fatty acids from the whole envelopes was markedly higher than that obtained from the ordinary cell walls. In both samples the major fatty acids were C(16) and C(18) acids. 2. The whole envelopes contained C(18) acids and long-chain (C(19)-C(26)) fatty acids, in a higher proportion than did the ordinary cell walls. Fifteen fatty acids with more than 18 carbon atoms were identified, among which 2-hydroxy-C(26:0) and C(26:0) acids predominated. 3. A complex sphingolipid containing inositol, phosphorus and mannose was isolated from the whole cell envelopes. The main fatty acids of this lipid were 2-hydroxy-C(26:0) and C(26:0) acids. It was concluded that this sphingolipid is present both in the ordinary cell wall and in the plasma membrane of baker's yeast. 4. The neutral lipids amounted to over 50% and the glycerophosphatides to about 30% of the total fatty acid content of the whole envelope. The major fatty acids in these lipids were C(16:1), C(18:1) and C(16:0) acids. The proportion of fatty acids with more than 18 carbon atoms was lowest in the neutral lipids, whereas the neutral glycolipids contained the highest percentage of these fatty acids. Acidic glycolipids amounted to 14% of the total fatty acid content of the whole envelope. The presence of a cerebroside sulphate in this lipid fraction was demonstrated, whereas the high content of 2-hydroxy-C(26:0) acid found is caused by the complex inositol- and mannose-containing sphingolipid.     

The lipid composition of plasma membrane from goat mammary gland

Experiments were conducted to examine and characterize the lipid composition of the plasma membrane from the lactating goat mammary gland. The plasma membranes were purified by discontinuous sucrose density centrifugation. Lipids were extracted from these membranes and analyzed by thin-layer and gas-liquid chromatography. The results of these studies demonstrate that (i) the principal phospholipids of mammary-gland plasma membranes are phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin; (ii) the principal neutral lipids are triacylglyceride and cholesterol ester; (iii) the major glycolipids are globotetraosylceramide and globotriaosylceramide; and (iv) the major fatty acids are oleic (18:1), palmitic (16:0), stearic (18:0), and myristic (14:0) acids.     

Adaptation of Synechococcus sp. PCC 7942 to phosphate starvation by glycolipid accumulation and membrane lipid remodeling

Organisms use various adaptive strategies against phosphate stress, including lipid remodeling. Here, the response of major membrane lipids to phosphate stress was analyzed in Synechococcus sp. PCC 7942. Unlike plants and eukaryotic microalgae, no significant increases in neutral lipids were found, whereas glycolipids content increased to as high as 6.13% (of dry cell weight, DCW) and phospholipids decreased to 0.34% (of DCW) after 16 days of cultivation without phosphate. Glycolipids accumulation were mainly attributed to the significant increase of digalactosyldiacylglycerol (DGDG) by 50% and sulfoquinovosyldiaclglycerol (SQDG) by 90%, both of which acted as complementary lipids for phosphatidylglycerol (PG) in the cyanobacterial membrane. Also, a notable increase in content (by 48%) of C18 fatty acids (especially C18:1) was observed in all glycolipids at the expense of C12 and C14 (72%). These changes may contribute to membrane fluidity and photosynthetic activity for basic cell metabolism and phosphate stress adaptation. Lipidomic analyses showed the reduction of PG 18:1/16: 0 (by 52%) with the increase of DGDG 18:1/16:0 (133%) and SQDG 18:1/16:0 (245%), strongly suggesting a direct conversion of PG to DGDG and SQDG. Moreover, the decreasing amount of monogalactosyldiacylglycerol (MGDG) 16:1/16:0 (22%) was consistent with the increase of free fatty acids (125%) on day 2 of phosphate absence, which suggested that MGDG is more likely to provide a pool of fatty acids for de novo synthesis of glycolipids. This study provides valuable insight into cyanobacteria adaptation strategies to phosphate stress by membrane lipid remodeling and unveils the underlying acyl chain fluxes into glycolipids.     

Lipid composition of PC12 pheochromocytoma cells: characterization of globoside as a major neutral glycolipid

We have studied the lipid composition of PC12 pheochromocytoma cells cultured in the presence and absence of nerve growth factor (NGF). Neutral and acidic lipid fractions were isolated by column chromatography on DEAE-Sephadex and analyzed by high-performance thin-layer chromatography (HPTLC). The total lipid concentration was approximately 220 micrograms/mg of protein, and the concentration of neutral glycolipids was 1.6-1.8 microgram/mg of protein for both NGF-treated and untreated cells. The neutral glycolipid fraction contained a major component, which accounted for approximately 80% of the total and which was characterized as globoside on the basis of HPTLC mobility, carbohydrate analysis, fast atom bombardment mass spectrometry, and mild acid hydrolysis. The major fatty acids of globoside were C16:0 (10%), C18:0 (16%), C22:0 (23%), C24:1 (17%), and C24:0 (24%). C18 sphingenine accounted for almost all of the long-chain bases. The other neutral glycolipids were tentatively identified as glucosylceramide (15%), lactosylceramide (4%), and globotriosylceramide (4.5%). The concentration of ganglioside sialic acid was approximately 0.34 and 0.18 microgram/mg of protein for cells grown in the presence and absence of NGF, respectively. Although there was an increase in ganglioside concentration in NGF-treated cells, NGF did not produce any differential effects on the relative proportions of the individual gangliosides. Several of the gangliosides appear to contain fucose, and one of these was tentatively identified as fucosyl-GM1. Brain-type gangliosides of the ganglio series were also detected by an HPTLC-immunostaining method. However, the fatty acid and long chain base compositions of PC12 cell gangliosides (and their TLC mobility) differ from those of brain gangliosides.(ABSTRACT TRUNCATED AT 250 WORDS)     

Synthesis of lipids from acetate by human preputial and abdominal skin in vitro

Lipogenesis in vitro from acetate-1-(14)C was studied in human preputial skin and abdominal skin. Radioactive lipids were separated by column chromatography on Florisil and by thin-layer chromatography on silica gel. Radioactivity was incorporated chiefly into the triglyceride, sterol, and polar lipid fractions, while lesser amounts of (14)C were found in the hydrocarbon, wax, diglyceride, monoglyceride, and fatty acid fractions; labeling of steryl esters was minimal. On thin-layer chromatography, the radioactive polar lipids had mobilities similar to lysolecithin, phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidic acid. The radioactive fatty acids of the different lipid fractions were separated by gas-liquid chromatography. The major (14)C-labeled acids were 16:0 and 18:0. Radioactivity was also detected in acids 14:0, 15:0, 16:1, 18:1, 18:2, 20:0, 20:1, 22:0, 24:0, 24:1, and 26:0. No radioactivity could be detected in arachidonic acid, although this fatty acid comprises 9% of the chromatographed fatty acids. The pattern of incorporated (14)C was different from the percentage mass composition of the fatty acids. Skin is therefore active in the biosynthesis of a wider variety of lipids than previously demonstrated.     

Changes in the lipid and fatty acid composition of hemolymph and ovaries during the reproductive cycle of Labidura riparia

Lipid metabolism was investigated during the reproductive cycle of Labidura riparia (Pallas). The lipid classes and their constitutive fatty acids present in hemolymph and ovaries were measured using thin‐layer chromatography and gas‐liquid chromatography. In the hemolymph, total lipids increase steadily from the previtellogenic period to vitellogenic arrest. These lipids are predominantly diacylglycerols and phospholipids. In the ovaries, total lipids increase during vitellogenesis then decrease during the vitellogenesis arrest period. The major lipids are triacylglycerols, followed by phospholipids. In both hemolymph and ovaries, all lipid classes contained variable proportions of seven main fatty acids: the saturated fatty acids myristic acid (14:0), palmetic acid (16:0), and stearic acid (18:0); the monounsaturated fatty acids palmitoleic acid (16:1) and oleic acid (18:1); and the polyunsaturated fatty acids linoleic acid (18:2) and linolenic acid (18:3). Unsaturated fatty acids predominate throughout the reproductive cycle. The percentage compositions of total and triacylglycerol fatty acids do not change markedly during the reproductive cycle in hemolymph nor in ovaries, with 18:2, 18:1 and 16:0 fatty acids being the major components. However, for diacylglycerols and phospholipids, the proportions of fatty acids vary systematically. For phospholipids during the vitellogenesis period, 18:2 increases considerably whereas other fatty acids decrease; for diacylglycerols, these fatty acids vary in the reverse way.     

Lipid composition of isolated epiphyseal cartilage cells, membranes and matrix vesicles.

1. Intact cells, cell fragments (membranes) and matrix vesicles were isolated from the proliferating and calcifying layers of epiphyseal cartilage by sequential hyaluronidase and collagenase digestion and differential centrifugation. Lipids were extracted and analyzed for various lipid classes and their fatty acid composition by column, thin-layer, paper and gas-liquid chromatography. 2. On a protein basis the isolated matrix vesicles had more total lipid than either the membrane or cell fractions, the vesicles and membranes being richer in non-polar lipids and containing smaller quantities of phospholipids than whole cells. Expressed as a percentage of the total lipid, the cells were richer in triacylglycerols and lower in free fatty acids than in the membrane or vesicle fractions. The proportion of free cholesterol and the cholesterol/phospholipid ratio were nearly twice as high in the matrix vesicles as in the other tissue fractions. Choline and ethanolamine phosphoglycerides progressively declined in the membrane and matrix vesicle fractions, whereas serine phosphoglycerides and sphinogomyelin increased. Non-phosphorus-containing polar lipids were present in all fractions, the vesicles being richer in polyhexosyl ceramides, cerebrosides, glycosyldiacylglycerols and certain uncharacterized acidic polar lipids. 3. Fatty acid patterns of the matrix vesicles were distinctive from those of isolated cells, being generally richer in 18 : 0 and 18 : 2, and lower in 16 : 1 and 18 : 1 fatty acids. Monoacyl forms were similarly increased in 16 : 0 and/or 18 : 0, and reduced in 16 : 1, 18 : 1 or 20 : 2 fatty acids, depending on the lipid class. The fatty acid composition of diphosphatidylglycerol from cells and matrix vesicles was markedly different, providing evidence that the cardiolipin in the vesicles was not from mitochondrial components. 4. Based on the fact that the matrix vesicles were significantly enriched in free cholesterol, sphingomyelin, glycolipids and serine-phosphoglycerides, it is concluded that they are derived from the plasma membrane of the cell, supporting earlier conclusions based upon morphological and enzymological evidence.     

Analyses of Pneumocystis Fatty Acids

The major ester-linked fatty acids of the total lipids extracted from Pneumocystis carinii isolated from the lungs of corticosteroid-trcaicd rats were 16:0. 18:0, 18:1, 18:2 and 20:4. Others detected included 14:0, 16:1 and 22:4. The major sphingolipid fatty acids were 16:0, 18:0,22:0,24:0 and 24:1; others included 14:0, 18:1, 20:0, 23:0, 24:2 and 26:0. The total lipid fatty acid compositions of preparations from appropriate lung controls were similar to those of the organism.     

Lipid composition of the epidermal gel secretion from the Arabian Gulf catfish (Arius thalassinus Ruppell)

Lipids associated with a threat induced epidermal gel secretion from the catfish, Arius thalassinus, have been analyzed. Phospholipids, neutral lipids and glycolipids are all present and each of these subclasses has been analyzed by thin layer and gas chromatography with a general similarity with membrane lipids being noted. The epidermal gel lipids differed from total liver lipids of the catfish. Fatty acid analysis showed the gel lipid to be rich in the unsaturated fatty acids: oleate (omega 7, C18:1), arachidonate (omega 6, C20:4), and docosahexaenoate (omega 3, C22:6). Some prostaglandins were quantitated in lipid extracts from the epidermal gel.     

Lipids of Rhizopus arrhizus Fischer

The lipids of Rhizopus arrhizus Fischer mycelia and sporangiospores were extracted, isolated, and separated by thin-layer, liquid, and gas chromatography. Structural confirmations of the compounds were made by a gas chromatographmass spectrometer combination. The n-heptane fraction contained squalene (1%) as a major hydrocarbon constituent. Other major lipid classes detected were free fatty acids, naturally occurring methyl esters of fatty acids, triglycerides, sterols, and polar lipids. The polar lipids (44.4%) were found in the highest concentrations, and the triglycerides (22.1%), sterols (16.7%), and free fatty acids (11.7%) were present in lesser concentrations. This is the first report of naturally occuring methyl esters of long-chain fatty acids being present in fungal mycelium. There appears to be a preference for incorporation of unsaturated acids into the complex lipids, with the exception of the triglycerides. The major saturated fatty acids in the mycelium were palmitic (C(16)) and arachidic (C(20)), whereas the major unsaturated acids were oleic (C(18:1)) and linoleic (C(18:2)), respectively.     

The fatty acids of Trypanosoma vivax

A study was carried out to determine the lipid composition of the blood-stream form of the African trypanosome. Trypanosoma vivax. Data from thin layer chromatography showed that the major polar lipids were lysophosphatidylcholine, sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and diphosphatidylglycerol. The major neutral lipids were sterol, monoacylglycerol, diacylglycerol, free fatty acid and triacyglycerol. 16:0, 18:0, 18:1 and 18:2 constituted the major fatty acids of both the polar and neutral lipid fractions. The work constituted the first detailed study on the fatty acid composition of this African trypanosome.     

Characterization of polar membrane lipids of the extremely halophilic bacterium Salinibacter ruber and possible role of cardiolipin

The lipid composition of the extremely halophilic bacterium Salinibacter ruber (Bacteroidetes) was investigated by thin layer chromatography, gas chromatography, high performance liquid chromatography and electrospray ionization-mass spectrometry. Polar lipids represent about 80% of the total lipid extract. The main polar lipids are a sulfonic acid analogue of ceramide (or capnine analogue), phosphatidylcholine, phosphatidylserine, dimethylphosphatidylethanolamine, phosphatidylglycerol, cardiolipin or bisphosphatidylglycerol, and a glycolipid. The major acyl chains in the phospholipids are C16:1 Delta9cis and C18:1 Delta11cis, while the sulfonolipid contains an amide-bound iso C15:0 fatty acid. On changing the salinity of the culture medium, no significant differences were found in the lipid profile or the unsaturation of the lipid fatty acyl chains. The structure of the cardiolipin, which represents 20% of polar lipids, has been elucidated by gas chromatography and electrospray ionization mass spectrometry analysis.     

Polar lipids and fatty acids of three wild cyanobacterial strains of the genus<Emphasis Type="Italic">Chroococcidiopsis</Emphasis>

The occurrence of n-saturated, branched, and unsaturated fatty acids of 3 wild terrestrial strains of the genus Chroococcidiopsis (Order Chroococcales): C. supralittoralis, C. umbratilis, and C. versatilis collected from Lake Kinneret, Dead Sea, and Ein Kerem (Jerusalem) was investigated and individual compounds identified by gas chromatography-mass spectrometry. Polar lipids also were examined. Among polar lipids (studied using two-dimensional thin-layer chromatography) were as major glycolipids isolated: monogalactosyl-diacylglycerols, digalactosyl-diacylglycerols, 6-sulfoquinovosyl-diacylglycerols and phosphatidylglycerol. Nonphosphorus betaine-containing lipid, viz. N,N,N-trimethylhomoserin-4-O-yl-diacylglycerol, was found for the first time in cyanobacterial species.     

Fatty acid and lipid compositions of Conidiobolus

The fatty acid composition of the total lipids from two Conidiobolus species was studied by gas—liquid chromatography. The major fatty acids of C. lamprauges were palmitic acid (C_16:0), oleic acid (C_18:1), linolenic acid (C_18:3), and arachidonic acid (C_20:4). For C. eurymitus , myristic acid (C_14:0), C_16:0, and linoleic acid (C_18:2) were the most abundant acids. The fatty acid composition of C. eurymitus was quite different from that of the Conidiobolus species as mentioned in other reports. The lipid composition of the total lipids of C. lamprauges and C. eurymitus was also studied by thinchrography on quartz rods. Triglycerides and phospholipids were the major components in the two Conidiobolus species.     

Composition and localization of lipids in Penaeus merguiensis ovaries during the ovarian maturation cycle as revealed by imaging mass spectrometry

Ovary maturation, oocyte differentiation, and embryonic development in shrimp are highly dependent on nutritional lipids taken up by female broodstocks. These lipids are important as energy sources as well as for cell signaling. In this study, we report on the compositions of major lipids, i.e. phosphatidylcholines (PCs), triacylglycerols (TAGs), and fatty acids (FAs), in the ovaries of the banana shrimp, Penaeus merguiensis, during ovarian maturation. Thin-layer chromatography analysis showed that the total PC and TAG signal intensities increased during ovarian maturation. Further, by using gas chromatography, we found that (1) FAs 14:0, 16:1, 18:1, 18:2, 20:1, and 22:6 proportionally increased as ovarian development progressed to more mature stages; (2) FAs 16:0, 18:0, 20:4, and 20:5 proportionally decreased; and (3) FAs 15:0, 17:0, and 20:2 remained unchanged. By using imaging mass spectrometry, we found that PC 16:0/16:1 and TAG 18:1/18:2/22:6 were detected in oocytes stages 1 and 2. PCs 16:1/20:4, 16:0/22:6, 18:3/22:6, 18:1/22:6, 20:5/22:6, and 22:6/22:6 and TAGs 16:0/16:1/18:3, 16:0/18:1/18:3, 16:0/18:1/18:1, and 16:0/18:2/22:6 were present in all stages of oocytes. In contrast, the PC- and TAG-associated FAs 20:4, 20:5, and 22:6 showed high signal intensities in stage 3 and 4 oocytes. These FAs may act as nutrition sources as well as signaling molecules for developing embryos and the hatching process. Knowledge of lipid compositions and localization could be helpful for formulating the diet for female broodstocks to promote fecundity and larval production.     

The isolation and partial characterization of glycolipids of normal human leucocytes

1. The lipids of purified human leucocytes were extracted with chloroform-methanol and the extract was washed with water. Glycolipids, isolated by Florisil chromatography, were subjected to mild alkaline hydrolysis and the alkali-resistant fraction was fractionated on a silicic acid column. 2. Three classes of glycolipid were separated. The less polar, containing 3.6% of the total glycolipid hexose as galactose, was tentatively identified as ceramide monohexoside. The major glycolipid fraction was characterized as ceramide dihexosides. The more polar glycolipids comprised 1.6% of the total glycolipid hexose as galactose and glucose (in the molar ratio 2:1) and were non-acidic. This class was separated as a mixture containing ninhydrin-positive glycolipids. 3. The ceramide dihexosides taken from two leucocyte preparations accounted for 15.2% and 16.4% by weight of the total lipids. 4. The carbohydrate moiety of the ceramide dihexosides contained galactose and glucose in the molar ratio 2:1. Partial acid hydrolysis and paper chromatography indicated that the hexoses are present as disaccharides, lactose being identified as one of them. 5. Palmitic acid (C(16:0)) and nervonic acid (C(24:1)) were the major fatty acids of this glycolipid. Hydroxy fatty acids were not detected.     

Characterization of polar membrane lipids of the extremely halophilic bacterium Salinibacter ruber and possible role of cardiolipin

The lipid composition of the extremely halophilic bacterium Salinibacter ruber (Bacteroidetes) was investigated by thin layer chromatography, gas chromatography, high performance liquid chromatography and electrospray ionization-mass spectrometry. Polar lipids represent about 80% of the total lipid extract. The main polar lipids are a sulfonic acid analogue of ceramide (or capnine analogue), phosphatidylcholine, phosphatidylserine, dimethylphosphatidylethanolamine, phosphatidylglycerol, cardiolipin or bisphosphatidylglycerol, and a glycolipid. The major acyl chains in the phospholipids are C16:1 Δ9cis and C18:1 Δ11cis, while the sulfonolipid contains an amide-bound iso C15:0 fatty acid. On changing the salinity of the culture medium, no significant differences were found in the lipid profile or the unsaturation of the lipid fatty acyl chains. The structure of the cardiolipin, which represents 20% of polar lipids, has been elucidated by gas chromatography and electrospray ionization mass spectrometry analysis.     

Triacylglycerol and phospholipid fatty acids of the silverleaf whitefly: composition and biosynthesis

The identification and composition of the fatty acids of the major lipid classes (triacylglycerols and phospholipids) within Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) nymphs were determined. Comparisons were made to fatty acids from the internal lipids of B. argentifolii adults. The fatty acids, as ester derivatives, were analyzed by capillary gas chromatography (CGC) and CGC-mass spectrometry (MS). All lipid classes contained variable distributions of eight fatty acids: the saturated fatty acids, myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), arachidic acid (20:0); the monounsaturated fatty acids, palmitoleic acid (16:1), oleic acid (18:1); the polyunsaturated fatty acids, linoleic acid (18:2), linolenic acid (18:3). Fourth instar nymphs had 5-10 times the quantities of fatty acids as compared to third instar nymphs and 1-3 times the quantities from adults. The fatty acid quantity differences between fourth and third instar nymphs were related to their size and weight differences. The percentage compositions for fatty acids from each lipid class were the same for the pooled groups of third and fourth instar nymphs. For nymphs and adults, triacylglycerols were the major source of fatty acids, with 18:1 and 16:0 acids as major components and the majority of the polyunsaturated fatty acids, 18:2 and 18:3 were present in the two phospholipid fractions, phosphatidylethanolamine and phosphatidylcholine. Evidence was obtained that whiteflies indeed synthesize linoleic acid and linolenic acid de novo: radiolabel from [2-(14)C] acetate was incorporated into 18:2 and 18:3 fatty acids of B. argentifolii adults and CGC-MS of pyrrolidide derivatives established double bonds in the Delta(9,12) and Delta(9,12,15) positions, respectively.