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.     

Temperature-dependent changes in phospholipid and fatty acid composition and membrane lipid fluidity of Yersinia enterocolitica

Temperature-dependent compositional changes of phospholipids and their fatty acids were analysed in Yersinia enterocolitica grown at 5°, 25° and 37°C. The relative amounts of the four phospholipids, phosphatidylethanolamine (75–78%), phosphatidylglycerol (10–11%), cardiolipin (<7%) and lysophosphatidylethanolamine (<5%), were essentially the same at all growth temperatures. The degree of fatty acid unsaturation of the four phospholipids increased with decrease in growth temperature, mainly due to an increase of C_16:1 and C_18:1 and a corresponding decrease of C_16;0, C_18:0 and cyclo C_17:0. An electron spin resonance spectroscopic study of the membrane lipids showed that membrane lipid fluidity was enhanced by decreasing the growth temperatures. The changes in fatty acid composition of phospholipids in response to varied temperatures were consistent with the temperature-dependent changes in the membrane lipid fluidity of Y. enterocolitica , and were similar to those reported for other bacteria.     

Effect of short-chain fatty acids on the ethylene pathway in embryonic axes of Cicer arietinum during germination

The effect of short-chain saturated fatty acids (C₅–C₁₀) on the biosynthesis of ethylene in embryonic axes of chick-pea ( Cicer arietinum L.) seeds was investigated. The emergence of radicle and fresh weight of embryonic axes diminished with increasing number of carbons. The inhibition of germination caused by lower concentrations (1 m M ) of fatty acids (C₅–C₁₀) was partially reversed by exogenous 1-aminocyclopropane-1-carboxylic acid (ACC), whereas exogenous ethylene was able to overcome the inhibitory effect provoked by all concentrations (1–5 m M ) of applied fatty acids (C₅–C₁₀). Ethylene production rates, and enzyme activities of ACC synthase and ACC oxidase decreased concomitantly with the molecular mass and increasing concentration of fatty acids. The inhibitory effect of these acids on ethylene production seems to result not only from a decreased ACC synthesis, but also from an enhancement of 1-malonylamino)cyclopropane-1-carboxylic acid (MACC) synthesis.     

Phototrophic growth on n-fatty acids by species of the genus Rhodocyclus sensu Imhoff et al.

Abstract Type strains of Rhodocyclus purpureus, R. gelatinosus and R. tenuis along with three local isolates of R. gelatinosus were tested for growth in the light on n -fatty acids ranging in chain length from C₅ (valerate) to C₂₂ (docosanoate).
R. purpureus , the type species of the genus, was anomalous in its limited ability to grow on n -fatty acids; no fatty acids of chain length greater than C₉ (nonanoate) were utilized. R. gelatinosus and R. tenuis , on the other hand, utilized all fatty acids in the range C₅ to C₁₈ inclusive. R. gelatinosus showed some restricted ability to use C₂₀ (eicosanoate) and C₂₂ (docosanoate) fatty acids.     

Wax Ester Production by the Marine Cryptomonad Chroomonas salina Grown Photoheterotrophically on Glycerol

SYNOPSIS. An age-autolyzed culture of Chroomonas salina , grown under cool-white light with glycerol, produced waxy lipid constituting about 44% of total matter harvested. This lipid was composed of 87% wax ester, 9% triglyceride, 3% polar lipid and 1% hydrocarbon. The major wax ester species were identified by total carbon number as C₂₆(28%), C₂₈(35%), C₃₀(15%). The main fatty acid components of the wax esters were 12:0 (39%), 14:0 (30%), 16:0 (14%), while the main alcohols were 14:0 (53%) and 16:0 (40%). The hydrocarbon fraction showed saturated paraffins ranging from C₁₇ to C₃₃, with odd-numbered chain components predominating. No polyunsaturated components were detected in the wax ester or hydrocarbon fractions. This is the first record of wax ester production by a cryptomonad or a marine phytoplankter.     

Fatty acids of leaf wax esters in Coincya Rouy (Brassicaceae)

A total of 46 populations belonging to the genus Coincya Ruoy (Brassicaceae) from the Iberian Peninsula was examined for their wax ester fatty acids composition. Size of ester fatty acids in the genus Coincya varies between 14 and 28 carbon atoms. This series is dominated by acids with an even number of carbon atoms. The most abundant acids are Ojg, C^y, C^^o and C₂₆ among evens and C₁₇ and C₂₁ among odds. A positive correlation was observed between chemical composition and environmental adaptation, and also with certain morphological characters. Changes relate to low temperatures or to high relative humidity, and there is a positive correlation between chemical composition and leaf glaucousness.     

LIPID CLASS DISTRIBUTION OF HIGHLY UNSATURATED LONG CHAIN FATTY ACIDS IN MARINE DINOFLAGELLATES

The very long chain highly unsaturated C₂₈ fatty acids, octacosaheptaenoic [28:7(n-6)] and octacosaoctaenoic acid [28:8(n-3)], were found to be associated with phospholipids, obtained by fractionation of total lipid extracts into distinct lipid classes, in 4 and 6, respectively, of 16 examined dinoflagellates. An interfraction comparison of fatty acids associated with phospholipids and glycolipids has also shown that the phospholipid fractions contained the majority (over 75% in 12 of 16 strains) of docosahexaenoic acid [22:6(n-3)] and traces of tetracosanoic acid (24:0). By contrast, the highly unsaturated C₁₈ fatty acids octadecatetraenoic [18:4(n-3)] and octadecapentaenoic acid [18:5(n-3)] were primarily recovered from a chloroplast-associated glycolipid fraction comprised of monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol. In 12 of 16 strains, an interfraction comparison showed that over 90% of 18:5(n-3) was found to be associated with glycolipids. These findings indicate that the C₂₈ fatty acids are located and probably synthesized in the cytoplasm or in an organelle other than the chloroplast, possibly with 22:6(n-3) and 24:0 as precursors, whereas the C₁₈ fatty acids 18:4(n-3) and 18:5(n-3) are glycolipid constituents apparently synthesized within the chloroplast. The function(s) of these C₂₈ fatty acids as components of phospholipids in cellular membranes is currently unknown.     

Cellular fatty acid composition in moderately halophilic Gram-negative rods

The fatty acid compositions for 40 strains of moderately halophilic Gram-negative rods were determined by gas-liquid chromatography. The strains studied were included in the genera: Vibrio, Deleya, Alteromonas, Chromobacterium, Flavobac-terium and Pseudomonas. Although there were quantitative differences all strains showed more or less similar spectra of fatty acids ranging from C₁₂ to C₂₀ chain. The major fatty acid species were C_16:0, C_16:1 and C_18:1. Most striking was the predominance of the C_18:1 component, the major fatty acid in extracts of 29 of the 40 strains.     

Uptake and utilization of n-octacosane and n-nonacosane by Arthrobacter nicotianae KCC B35

Arthrobacter nicotianae KCC B35 isolated from blue-green mats densely covering oil sediments along the Arabian Gulf coast grew well on C₁₀ to C₄₀ n -alkanes as sole sources of carbon and energy. Growth on C₂₀ to C₄₀ alkanes was even better than on C₁₀ to C₁₈ alkanes. Biomass samples incubated for 6 h with n -octacosane (C₂₈) or n -nonacosane (C₂₉) accumulated these compounds as the predominant constituent alkanes of the cell hydrocarbon fractions. The even chain hexadecane C₁₆ and the odd chain pentadecane C₁₅ were the second dominant constituent alkanes in C₂₈ and C₂₉ incubated cells, respectively. n -Hexadecane-incubated cells accumulated in their lipids higher proportions of C₁₆-fatty acids than control cells not incubated with hydrocarbons. On the other hand, C₂₈ and C₂₉-incubated cells did not contain any fatty acids with the equivalent chain lengths, but the fatty acid patterns of the cell lipids suggest that there should have been mid-chain oxidation of these very long chain alkanes. This activity qualifies A. nicotianae KCC B35 to be used in cocktails for bioremediating environments polluted with heavy oil sediments.     

Effect of non-target cells on the sensitivity of the PCR for Escherichia coli O157 : H7

The fatty acid composition from mycelia of Streptomyces hygroscopicus strains was studied. A significant proportion of C_{18 : 2} was found in cultures. High levels of C_{16 : 0}, iso-C_{16 : 0} and C_{18 : 1} were also detected in all S. hygroscopicus strains. The different representatives of S. hygroscopicus had almost the same proportion of unsaturated fatty acids. Certain shifts in the amount of iso, anteiso and straight-chain fatty acids in some cultures were revealed. This might be explained by the adaptation capability of strains belonging to one species to form a variety of available fatty acids determined by particular cell membrane composition favouring certain antibiotic biosynthesis.     

PELIZAEUS-MERZBACHER DISEASE: BRAIN LIPID AND FATTY ACID COMPOSITION

Abstract— Biochemical analysis of the leukodystrophy brain from a case of Pelizaeus-Merzbacher disease, classical type, was performed. A decrease in the amount of solid material present was found. The lyophilized brain weight was reduced to 76% of normal with a slightly greater decrease in the amount of extractable lipid. Total myelin was diminished to 7% of normal. Among specific lipids plasmalogens were present in slightly lowered amounts. Cerebrosides and sulphatides were drastically reduced to 8% of normal, whereas sphingomyelin was less severely affected. Fatty acids from phospholipids were close to normal, only enols being slightly diminished. Analysis of pure cerebrosides and sulphatides revealed that the a-hydroxylated compounds as well as very long chain fatty acids (over C₁₈, especially C₂₃ to C₂₆) were greatly reduced. For chain lengths over C₁₈, the ratio of leukodystrophy fatty acid to normal fatty acid was close to 10%. The defect in very long chain fatty acids is estimated at 99.2% in total brain.
Thus, we have found a marked decrease in the amount of very long chain fatty acids and a less marked decrease in sphingolipids. The reduced amount of these acids appears to be partially offset by an increase in the amount of medium-chain fatty acids in sphingolipids. We conclude that one aspect of Pelizaeus-Merzbacher disease may be a defect in the synthesis of myelin very long chain fatty acids (as these acids are far much reduced than any other myelin molecule).     

Phospholipids of Fusobacterium spp.

The aim of this study was to analyse individual polar lipid analogues, within each lipid family present, of fusobacteria using fast atom bombardment mass spectrometry (FAB-MS). Polar lipid extracts were prepared, washed and dried. Samples, dispersed in a matrix of m -nitrobenzyl alcohol, were analysed by negative ion FAB-MS using xenon as the reagent gas. Major anion peaks observed in the low mass region of mass/charge (m/z), 211, 221, 225, 227, 239, 241, 249, 251, 253, 255, 273, 277, 279, 281, 289 and 291, were consistent with the presence of C_13:1, C_14:3, C_14:1, C_14:0, C_15:1, C_15:0, C_16:3, C_16:2, C_16:1, C_16:0, unknown, C_18:3, C_18:2, C_18:1, unknown and C_19:3 carboxylate anions. In the high mass region, major anion peaks observed with m/z 644, 646, 648, 660, 662, 672, 673, 674, 686, 688, 689, 690, 698, 700, 701, 703, 714, 716, 717 and 719 were consistent with the presence of phosphatidylethanolamine (PE) (29:2), PE (29:1), PE (29:0), PE (30:1), PE (30:0), PE (31:2), first isotope of PE (31:2), PE (31:1), PE (32:2), PE (32:1), first isotope peak of PE (32:1), PE (30:0), PE (33:3), PE (33:2), phosphatidylglycerol (PG) (31:3), PG (31:2), PE (34:2), PE (34:1), PG (32:2) and PG (32:1). We conclude that FAB-MS can provide data on individual analogues of PE and PG from Fusobacterium spp. not readily obtained by other means. Furthermore, the phospholipid profile is diagnostic for the genus.     

FATTY ACID COMPOSITION OF CEREBROSIDES, SULPHATIDES AND CERAMIDES IN MURINE LEUCODYSTROPHY: THE QUAKING MUTANT

Abstract— The fatty acid composition of cerebrosides, sulphatides and ceramides has been determined at 20 days postpartum in the brains of Quaking mutant mice and of littermate controls. There was a significant deficit in the proportion of long-chain fatty acids (C₂₂-C₂₄) affecting both normal and a-hydroxy fatty acids of the cerebrosides. The proportion of normal but not the a-hydroxy long-chain fatty acids of the sulphatides was also decreased. Striking and disproportionate deficits of the C_24:1 and C_{24 h:1} fatty acids of cerebrosides, sulphatides and ceramides characterized the brain of the Quaking mutant, and an increased proportion of C_{23 h:O} fatty acid was found in the cerebrosides and sulphatides of the brain of this mutant. We compared these data with findings on the Jimpy mutant which has been examined by the same techniques. The deficiency of long-chain fatty acids which was found in the cerebrosides and sulphatides of both mutants was less extensive but more selective in the Quaking mutant.     

Arabidopsis CER8 encodes LONG-CHAIN ACYL-COA SYNTHETASE 1 (LACS1) that has overlapping functions with LACS2 in plant wax and cutin synthesis

Plant cuticle is an extracellular lipid-based matrix of cutin and waxes, which covers aerial organs and protects them from many forms of environmental stress. We report here the characterization of CER8 / LACS1 , one of nine Arabidopsis long-chain acyl-CoA synthetases thought to activate acyl chains. Mutations in LACS1 reduced the amount of wax in all chemical classes on the stem and leaf, except in the very long-chain fatty acid (VLCFA) class wherein acids longer than 24 carbons (C₂₄) were elevated more than 155%. The C₁₆ cutin monomers on lacs1 were reduced by 37% and 22%, whereas the C₁₈ monomers were increased by 28% and 20% on stem and leaf, respectively. Amounts of wax and cutin on a lacs1-1 lacs2-3 double mutant were much lower than on either parent, and lacs1-1 lacs2-3 had much higher cuticular permeability than either parent. These additive effects indicate that LACS1 and LACS2 have overlapping functions in both wax and cutin synthesis. We demonstrated that LACS1 has synthetase activity for VLCFAs C₂₀–C₃₀, with highest activity for C₃₀ acids. LACS1 thus appears to function as a very long-chain acyl-CoA synthetase in wax metabolism. Since C₁₆ but not C₁₈ cutin monomers are reduced in lacs1 , and C₁₆ acids are the next most preferred acid (behind C₃₀) by LACS1 in our assays, LACS1 also appears to be important for the incorporation of C₁₆ monomers into cutin polyester. As such, LACS1 defines a functionally novel acyl-CoA synthetase that preferentially modifies both VLCFAs for wax synthesis and long-chain (C₁₆) fatty acids for cutin synthesis.     

Lipid and pigment composition of a chlorophyll b-deficient mutant of Chlamydomonas reinhardii

Lipids and pigments of the chlorophyll b -deficient mutant pg-113 and the parent strain (ps) of Chlamydomonas were analysed and compared. Monogalactosyldiglyceride, digalactosyldiglyceride, diacylglyceryl(N, N, N-trimethyl)homoserine, sulfoquinovosyldiglyceride, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol were found as major lipid components. While the lipid patterns were qualitatively and quantitatively almost the same in the two strains, the C₁₆/C₁₈ fatty acid ratios were different, 0.85 in the mutant and 1.11 in the parent strain. Furthermore, the relative amounts of C₁₆- and C₁₈-monoene fatty acids were slightly enhanced and the C₁₈-trienes slightly reduced in the mutant. In the parent strain, chlorophylls a and b , α- and β-carotene, lutein, violaxanthin, neoxanthin and loroxanthin were detected by HPLC. In the mutant, similar pigments were found, except that only traces of chlorophyll b and a reduced amount of neoxanthin were present. Since no chlorophyll-protein complex CP II could be detected in the mutant by electrophoresis, the possible interrelationships between pigment deficiency and alteration of chlorophyllprotein complexes are discussed.     

Induction of acetoacetate decarboxylase in Clostridium acetobutylicum

Abstract Factors that may initiate the biosynthesis of acetoacetate decarboxylase were investigated in resting cells of Clostridium acetobutylicum . Linear acids from C₁ to C₄ were inducers, whereas branched acids and linear acids from C₅ to C₇ were not inducers of acetoacetate decarboxylase biosynthesis. Induction of acetoacetate decarboxylase was maximal at pH 4.8 in the presence of acid concentrations comparable with those found during fermentation. In growth conditions repression of acetoacetate decarboxylase biosynthesis was found. This fact explains that acetone production by Clostridium acetobutylicum occurs when growth slows down.     

Influence of plasma lipid changes in response to 17β-oestradiol stimulation on plasma growth hormone, somatostatin, and thyroid hormone levels in immature rainbow trout

Plasma total lipids were significantly higher in 17β-oestradiol(E₂)-treated immature rainbow trout Oncorhynchus mykiss at week 4 after implantation, due to increases in polar and neutral lipids. The lipid classes responding were phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, sterols and sterol esters, in a proportion that approximately reflected the increase in plasma vitellogenin (VtG) levels as measured by a non-competitive enzyme-linked immunosorbent assay (ELISA). Plasma non-esterified fatty acids and triacylglycerol were not affected by E₂ treatment. Plasma growth hormone GH levels were increased, and plasma somatostatin-14 (SRIF) levels decreased in E₂-treated fish, responses which could be secondary to elevated plasma lipid (VtG) content, although a direct E₂ action on somatotroph function is possible. Plasma T₄ concentrations were not affected by E₂ treatment, but plasma T₃ concentrations were significantly lower than in controls 1 week after implantation when plasma E₂ concentrations were the highest; this is in support of the hypothesis that E₂ has a suppressive action on T₃ production.     

Lipid Investigation of Central and Peripheral Nervous System in Connatal Pelizaeus-Merzbacher's Disease

Abstract: Brain grey and white matter of a case of Pelizaeus-Merzbacher disease (connatal type Seitelberger) of a 19-month-old boy were analysed with respect to lipids. Cerebrosides and sulfatides were totally absent in the pathological brain. In comparison to control, differences in gangliosides could be detected in grey and white manner. C_18:1, fatty acids were markedly reduced in the main glycerophospholipids of white matter. In sphingomyelin of cortex and white matter 90% of fatty acids were C_18:0; longer chains were absent. In contrast: PNS (nervus fernoralis) lipids contained the main galactolipids. However, these a s well as all other lipid classes showed a 20% reduction compared with values obtained from nervus femoralis of an infant of the same age. The fatty acid patterns of all lipid classes were determined. The only marked deviations from normal were observed in the C₂₄-chains of cere-brosides and sulfatides. The formalin-fixed brain of an older brother (same disease) was analysed only with respect to glycolipids: neither cerebrosides nor sulfatides could be detected.     

Myelin Gangliosides: An Unusual Pattern in the Avian Central Nervous System

Abstract: Gangliosides were isolated from purified myelin obtained from brain and spinal cord of mature chickens and pigeons. Total concentrations were approximately two- to fivefold greater than for previously reported mammalian species, and their patterns also differed in containing significantly more sialosylgalactosylceramide (G_M4). The latter comprised one-third to one-fourth of total myelin ganglioside, approximately equivalent to G_M1 (II³NeuNAc-GgOse₄Cer). As in mammals, G_M4 of avian CNS appeared to be localized in myelin. Fatty acids of this ganglioside included both the hydroxy- and unsubstituted types. and, long-chain bases were almost entirely C₁₈. Ganglioside G_M1 split into two closely migrating bands on TLC, the slower of which resembled mammalian G_M1 in having stearate as the main fatty acid with a measurable amount (10%) of C₂₀-sphingosine; the faster band had predominantly longer-chain fatty acids and very little C₂₀-sphingosine.     

Free fatty acids, neutral and polar lipids in Hordeum vulgare exposed to long-term fumigation with SO2

Three 9-day-old cultivars of Hordeum vulgare L. (Barberousse, Gerbel and Panda) were exposed to low levels of SO₂ fumigation (40 ± 5 and 117 ± 20 ppb). After 48 days of treatment the seedlings were harvested for lipid analysis. In comparison to the control (plants exposed to charcoal-filtered air), the total lipid content of fumigated seedlings declined at 40 ppb SO₂ and even more so at 117 ppb in all three cultivars. A large reduction in diacylglycerols. polar lipids and free sterols was also observed after fumigations at both SO₂ concentrations, whereas the treatments resulted in an increase in triacylglycerols and free fatty acids. The percentage composition of total fatty acids and that of each lipid class were changed by the fumigations. resulting in an increase in the degree of unsaturation. No changes in the percentage composition of sterols occurred in the fumigated leaves. These results suggest that even if SO₂ may not directly oxidize unsaturated fatty acids at the low concentrations used here (which do not cause visible injury). it may alter lipid metabolism. This alteration. which was particularly evident in the polar lipids and sterols, could affect the functions associated with membrane stabilization, in which lipids plus sterols play a key part.