Lipid metabolism ofAgaricus bisporus (Lange) sing.: I. Analysis of sporophore and mycelial lipids

The lipid components of four strains ofAgricus bisporus (Lange) Sing., the cultivated mushroom, were analyzed. Both sporophore and mycelial samples were obtained from beds in normal production. A method for obtaining mycelium free of compost was developed. Neutral lipids were separated from polar lipids by silicic acid column chromatography. Each fraction was separated by thin layer chromatography. Fatty acid methyl esters were analyzed by gas liquid chromatography and mass spectrometry. Sporophore extracts contained free sterol, free fatty acid, triglycerides, phosphatidyl choline and phosphatidyl ethanolamine. High amounts of linoleic acid were found in both neutral and polar lipid fractions. Mycelial extracts contained free fatty acids, triglycerides, phosphatidylcholine and phosphatidyl ethanolamine. No free sterol could be detected. Linoleic acid was also present in large amounts. Paper 3798 in the Journal Series of The Pennsylvania Agricultural Experiment Station.     

A comparative study of the lipids of chylomicron membrane and fat core and of the lymph serum of dogs

Thoracic lymph was collected from 13 dogs fed corn oil and butterfat. The chylomicrons were isolated by centrifugation. The lipid composition of the fat core and the membrane of the chylomicron was compared to that of the surrounding lymph serum. The fat cores contained 90–96% triglyceride, 0.7–1.9% free cholesterol, 0.2–0.5% steryl ester, 0.9–3.5% free fatty acid and 1.4–6.1% diglyceride, but no phospholipid. The lipids of the membranes contained 58–75% phospholipid, 20–35% triglyceride, 2–5% free cholesterol, 1–2% free fatty acid, and 2–3% diglyceride, but little or no steryl ester. The membrane phospholipids were made up of 70–90% lecithin, 5–20% phosphatidyl ethanolamine, and 1–3% each of lysolecithin and sphingomyelin. The lymph serum contained 24–47% of total lipid as phospholipid, of which 70–92% was lecithin; the phosphatidyl ethanolamine, lysolecithin and sphingomyelin also present contributed 1–10% each. The neutral lipids of the lymph serum contained 49–75% triglyceride, 2–15% free cholesterol, 6–23% esterified cholesterol, 10–33% free fatty acid and 1–6% diglyceride. Alterations in dietary fat, or plant sterol supplementation led to lesser changes in the lipids of the chylomicron membranes than in the lipids of any other lymph fraction. The least variation was seen in the phospholipids. Taken in part from a PhD Thesis submitted by T. C. Huang to Queen's University, Kingston, Canada, in April 1965. Presented at the AOCS 56th Spring Meeting, Houston, May 1965.     

Lipid composition of further purified bovine liver nuclear membranes

The lipid content, distribution and fatty acid composition of highly purified bovine liver nuclear membranes was determined and compared to those of microsomes prepared in parallel. Contrasted with microsomes, nuclear membranes while containing nearly the same levels of lipid had more cholesterol and total neutral lipid and less phospholipid. Phospholipid and neutral lipid patterns generally were similar for the two types of membranes. The same fatty acids, in similar proportions, were observed in respective total lipid, total polar lipid, phosphatidyl choline and phosphatidyl ethanolamine fractions of the two membrane types. The microsomal lipid fractions contained slightly greater percentages of unsaturated fatty acids. With respect to previous results from preparations contaminated with nonmenbranous nuclear material, purified fractions contained more total lipid on a protein basis and more total unsaturated fatty acids. Only minor differences in levels and distribution of phospholipids and neutral lipids were observed between the crude and highly purified fractions. Purdue University AES Journal Paper No. 4482.     

Polar lipids ofMacrophomina phaseolina

Macrophomina phaseolina was grown on a defined medium at three different carbon/nitrogen ratios. The lipids of the mycelia and the sclerotia were extracted; fractionated into polarity groups; and separated by thin layer, column, and gas liquid chromatographies. Sclerotia contained higher levels of neutral lipids and lower amounts of polar lipids than mycelia. The neutral lipid content of sclerotia increased, up to 77% of total lipids, and phospholipids decreased as carbon/nitrogen ratio increased from 10 to 320. The glycolipid content was not altered significantly by changes in carbon/nitrogen ratios. Although cardiolipin could not be detected in sclerotial polar lipids, both sclerotia and mycelia contained similar phospholipid profiles with major quantitative differences. Phosphatidic acid and phosphatidyl glycerol were major components of sclerotia, whereas phosphatidyl ethanolamine and phosphatidyl inositol were the major phosphatides of mycelia. Phosphatidyl choline was present in both mycelia and sclerotia. The fatty acid distribution did not show any particular pattern of saturation or unsaturation due to differences in carbon/nitrogen ratio. However, mycelial lipids tended to contain C24∶1, C18∶3, and C22∶1 as major fatty acids, whereas the major fatty acids in sclerotial lipids were C18∶2, C18∶1, C22∶1, C20∶0, and C16∶1. Saturated fatty acids were present in lesser concentrations.     

Phospholipid Composition of <Emphasis Type="Italic">Jatropha curcus</Emphasis> Seed Lipids

Jatropha curcus L. oil has emerged as one of the most important raw materials for biodiesel production. However, no detailed study has been reported on characterizing the lipid constituents of jatropha oil. The present study revealed that the total oil content of jatropha seeds was 32% with a composition of 97.6% neutral lipids, 0.95% glycolipids and 1.45% phospholipids. The fatty acid composition of total lipids, neutral lipids, phospholipids and glycolipids was also determined and found to contain oleic acid (18:1) and linoleic acids (18:2) as major fatty acids. The phospholipids fraction was further characterized and quantified and found to contain phosphatidyl choline (PC) 60.5%, phosphatidyl inositol (PI) 24% and phosphatidyl ethanolamine (PE) 15.5%. The fatty acid composition and the positional distribution of the fatty acids of individual phospholipids were also reported.     

Lipid composition of normal and hypertrophic bovine thyroids

The phospholipid content of bovine thyroid tissue amounts to 70% of total lipid. Triglycerides and cholesterol are the main neutral lipids. Only trace amounts of free fatty acid and esterified cholesterol are found, while two not yet identified components also are present. The distribution of lipid phosphorus in the different phospholipid classes is as follows: phosphatidyl choline, 43.0%; phosphatidyl ethanolamine, 25.2%; phosphatidyl serine, 5.6%; phosphatidyl inositol, 6.5%; sphingomyelin, 14.0%; cardiolipin, 2.8%; lysophosphatidyl choline, <1%; and phosphatidic acid, <1%. The phosphatidyl ethanolamines are rich in plasmalogens. The fatty acid patterns in the different lipid classes are reported. The essential differences between normal and hypertrophic bovine thyroid tissue are higher water content and lower triglyceride and sphingomyelin values for hypertrophic tissue.     

Comparison of lipid composition ofCandida guilliermondii grown on glucose,ethanol and methanol as the sole carbon source

The carbon and energy source for aerobically grown cultures ofCandida guilliermondii profoundly influenced the neutral lipid content and the fatty acid composition of the individual lipid components. Methanol (0.80%, w/v) grown cells cultivated at 30 C in presence of 0.025% ammonium sulfate contained 12% total lipids, 67% of which was neutral lipids. Glucose (0.74%, w/v) or ethanol (0.53%, w/v) grown cells contained 21–22% total lipids, 80% of which was neutral lipids, under the same conditions. Methanol-grown cells contained a decreased 18∶1 acid (52–54% of total fatty acids) and an increased 18∶2 acid (23–25%), as compared with glucose- or ethanol-grown cells which contained 57–66% 18∶1 acid and 8–14% 18∶2 acid, in both neutral and polar lipid fractions. The relationship between methanol metabolism and desaturation of fatty acid in yeast was discussed.     

A comparative study of the lipids of globule membrane and fat core and of the milk serum of cows

Nine samples of fresh raw cow's milk were separated into fat globules and milk serum by centrifugation. After destabilization by freezing and thawing, the milk fat globules were resolved into membranes and fat cores. The lipid composition of these structures was compared to that of the surrounding milk serum. Of the total milk fat, 95–98% was in the fat cores, 0.5–1% in the globule membranes and the rest (1.5–4%) in the milk serum. The fat cores contained 88–93% triglyceride, 5.2–9.8% diglyceride, 1.5–7.3% free fatty acid and 0.2–0.4% cholesterol, but no phospholipid. The lipids of the membrane contained 21–44% phospholipid, made up of about equal proportions of phosphatidyl ethanolamine, phosphatidyl choline, and sphingomyelin. The other lipids of the membrane (56–79%) consisted of 83–88% triglyceride, 5.1–10.7% diglyceride, 1–5.1% free fatty acid and 0.4–1.9% cholesterol. The milk serum contained 30–45% phospholipid divided about equally among phosphatidyl ethanolamine, phosphatidyl choline and sphingomyelin. The rest (55–70%) of the milk serum lipids was made up of 71–83% triglycerides, 4.3–10.1% diglycerides, 8.7–15.7% free fatty acids, and 1.2–8.4% cholesterol. Corresponding phospholipid classes of milk serum and globule membranes had identical fatty acid compositions. The triglycerides and diglycerides of the globule membranes possessed increased proportions of palmitic and stearic acids in comparison to the glycerides of the fat cores. Taken in part from a PhD thesis submitted by T. C. Huang to Queen's University, Kingston, Canada in April, 1965. Presented in part at the 47th Canadian Chemical Conference and Exhibition held in Kingston, Canada, June 1–3, 1964.     

Lipid composition of beef and human pituitary glands

The lipid composition of beef and human pituitary was determined by chromatographic and spectrophotometric methods. Beef pituitary lipid contained about 25% nonpolar lipids and 75% phospholipids whereas nonpolar lipids made up approximately 60% of the total in human pituitaries. The main nonpolar (i.e., low polarity) lipids in human pituitary were triglycerides, cholesterol, free fatty acids and an unidentified component in the triglyceride fraction. Cholesterol was the major nonpolar lipid component in freshly collected beef anterior and posterior pituitary, but the amount of free fatty acids appeared to increase during storage. Preliminary investigation of the unknown nonpolar lipid in human pituitaries suggested that it was an unsaturated hydroxy compound with no carbonyl functions. Thin layer chromatography indicated that it was also present in smaller amounts in freshly collected beef pituitaries. The main phospholipids of beef anterior, posterior and human pituitary were phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl inositol, phosphatidyl serine and sphingomyelin. The fatty acid composition of total nonpolar lipids, free fatty acids, total phospholipids, phosphatidyl ethanolamine and phosphatidyl choline of beef anterior and posterior pituitary was determined by gas liquid chromatography. Mixtures of saturated and unsaturated fatty acids ranging from C₁₂ to C₂₂ were present; the main fatty acids were palmitic, stearic, oleic, linoleic and arachidonic.     

Lipids ofKlebsiella pneumoniae: The presence of phosphatidyl choline in succinate-grown cells

The carbon and energy source for aerobically grown cultures ofKlebsiella penumoniae profoundly influenced the total lipid content and phosphatide composition. Glucose-grown cells contained 13% lipid, 56% of which was phospholipids. Succinate-grow cells contained 8% lipid, 66% of which was phospholipids. The predominant phosphatides of glucose-grown cells were phosphatidyl ethanolamine, 82%; phosphatidyl glycerol, 4.5%; phosphatidic acid, 5%; cardiolipin, 6.5%; phosphatidyl serine; and trace amounts of unidentified phosphatides. Phosphatides of succinate-grown cells were phosphatidyl ethanolamine, 38%; diphosphatidyl glycerol, 14%; phosphatidyl glycerol, 13%; phosphatidyl choline, 14.5%; phosphatidyl serine, 6%; phosphatidic acid, 4%; and 10% unknown lipids. No trace of phosphatidyl choline was found in glucose-grown cells. Paper 75-11-170 of the Kentucky Agricultural Experiment Station.     

Lipids of some thermophilic fungi

Total lipid content in the thermophilic fungi—Thermoascus aurantiacus, Humicola lanuginosa, Malbranchea pulchella var.sulfurea, andAbsidia ramosa—varied from 5.3 to 19.1% of mycelial dry weight. The neutral and polar lipid fractions accounted for 56.4 to 80.2% and 19.8 to 43.6%, respectively. All the fungi contained monoglycerides, diglycerides, triglycerides, free fatty acids, and sterols in variable amounts. Sterol ester was detected only inA. ramosa. Phosphatide composition was: phosphatidyl choline (15.9–47%), phosphatidyl ethanolamine (23.4–67%), phosphatidyl serine (9.3–17.6%), and phosphatidyl inositol (1.9–11.9%). Diphosphatidyl glycerol occurred in considerable quantity only inH. lanuginosa andM. pulchella var.sulfurea. Phosphatidic acid, detected as a minor component only inM. pulchella var.sulfurea andA. ramosa, does not appear to be a characteristic phosphatide of thermophilic fungi as suggested earlier. The 16∶0, 16∶1, 18∶0, 18∶1, and 18∶2 acids were the main fatty acid components. In addition,A. ramosa contained 18∶3 acid. Total lipids contained an average of 0.93 double bonds per mole of fatty acids, and neutral lipids tend to be more unsaturated than phospholipids.     

Total,polar and neutral lipids ofRhizopus arrhizus fischer

The changes in total lipid content, neutral and polar lipids, total fatty acids, and free fatty acids were investigated over a 4 day period in the zygomycete,Rhizopus arrhizus Fischer. The highest concentration of lipids occurred at the 72 hr period. The degree of unsaturation in the total fatty acid fraction increased during the growth period, whereas the degree of unsaturation decreased in the free fatty acid fraction during the same time period. The ratios of neutral to polar lipids over the 4 day period were: 0.75, 0.22, 1.94 and 0.94. The major components of polar lipids were phosphatidyl ethanolamine, lecithin, lysolecithin, and fatty acids. The fatty acids in the mono- and diglycerides were predominately saturated (67–96%). The fatty acids in the triglycerides shifted from a predominately unaturated (69%, 24 hr) to a more saturated pattern (62%, 96 hr).     

Lipid from yeast fermentation: Effects of cultural conditions on lipid production and its characteristics of rhodotorula glutinis

To produce lipids from microbial origins, Rhodotorula glutinis (syn. Rhodotorula gracilis) NRRL Y-1091 was cultured in batch and continuous systems under nitrogen- and carbon-limited conditions. The lipid production patterns are shown to be different from each other depending on growing conditions. In continuous cultures under nitrogen-limited conditions, the maximum lipid accumulation was observed at the lowest dilution rate examined, giving the efficiency of substrate conversion of 16.4 g lipid per 100 g glucose consumed. As the dilution rate increased, cell biomass, lipid content, lipid productivity and lipid yield decreased. In carbon-limited continuous cultures, cell biomass decreased with increasing dilution rate, but lipid content remained almost constant. Neutral lipid portions in nitrogen-limited cultured yeast cells decreased as the dilution rate increased, and glyco- and phospholipid portions showed the reverse trend. Major components in the neutral lipid portions in yeast cells are triglyceride, free fatty acid, steryl ester and sterol. Phosphatidylserine was the predominant phospholipid in yeast cells. The dilution rate also affected the fatty acid composition of all lipid portions; polyunsaturated fatty acids increased and saturated and monounsaturated fatty acids decreased with increasing dilution rates. The degrees of unsaturation of each lipid class and total lipids were also increased by increasing the dilution rate.     

The lipid components of white potato tubers (Solanum tuberosum)

Four Canadian varieties of potatoes were examined for their lipid composition. Lipids, extracted with chloroformmethanol, were shown by TLC and column chromatography to consist of 16.5% neutral lipids, 45.5% phospholipids and 38.1% glycolipids. Among the phospholipids and glycolipids, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, the galactolipids and the sterol glucosides were the major lipids. The predominant fatty acids were palmitic (19.5%), linoleic (44.8%) and linolenic (30.4%, in Kennebec). Analyses of the fatty acids of stored potatoes showed a marked decrease in linoleic acid and an increase in linolenic acid, in the Irish Cobbler and Sebago potatoes. β-sitosterol comprised 85.0% of total sterols. Nearly half of the carotenoids was lutein (xanthophyll), the others being α-carotene, β-carotene, an unidentified pigment and lutein epoxide. Contribution No. 101 of the Food Research Institute, Canada Department of Agriculture.     

Effect of excessive fatty acid ingestion upon composition of neutral lipids and phospholipids of snailHelix pomatia L.

The effect of an excessive intake of oleic acid on the lipids of the Roman snail (Helix pomatia L.) was studied. The total lipid content increased by 30% which was fully attributable to a marked elevation in the neutral esters and free fatty acids, as phospholipid and free sterol contents remained unaffected. The fatty acid composition of the phospholipids, characterized by high amounts of stearic, linoleic, homolinoleic, and, particularly, arachidonic acids, appeared to be nearly insensitive to this excessive oleic acid ingestion. By contrast, the effect of oleic acid upon the depot lipids was striking: active intestinal resorption of the acid from the dietary supply was shown by the fourfold level of lleic acid in the free fatty acid fraction, whereas a fivefold level of this acid in the glyceride and sterol ester fraction was proof of a substantial esterification. These data support the view that the composition of the structural lipids is specifically species oriented, whereas both the content and the composition of the depot lipids are highly governed by dietary fat intake.     

Studies on the lipid composition of developing soybeans

Studies are reported on changes in fatty acid and lipid class composition in developing soybeans picked at intervals from ca. nine days after flowering to maturity. In the early stages of development of the bean, the lipid was virtually devoid of triglyceride and the major constituents consisted of glycolipids and phospholipids. As the bean developed, there was a rapid synthesis of triglyceride that paralleled the deposition of lipid. Simultaneously, unknown substances which occurred in relatively large amounts in the neutral, as well as the glycolipid and phospholipid, fractions of the immature bean diminished to less than 2% of the total lipid in the mature bean. The glycolipids and phospholipids also increased as the bean developed but at a much slower rate than the triglycerides and became minor components in the mature bean. The major component of the phospholipids in the immature bean was phosphatidic acid. It decreased as the phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl inositol, as well as triglyceride, increased. The major component of the glycolipid fraction in the early stages of the development of the bean had the same migration pattern on two-dimensional thin layer chromatography as phosphatidic acid and gave a positive test for phosphorus; it also gave a positive test for glycolipids and was separated completely from phosphatidic acid and other phospholipids by column chromatography. It also decreased as the bean developed. Changes also occurred in the fatty acid composition of the developing bean. The percentage of saturated fatty acids decreased rapidly in the early stages of the development of the bean; oleic and linoleic increased rapidly as the bean developed. Linolenic acid increased rapidly to a maximum concentration in the early stages of the development of the bean and then gradually decreased as the bean matured.     

Thermophilic fungi: III. The lipids ofHumicola grisea var.thermoidea

The lipids of the thermophilic fungusHumicola grisea var.thermoidea were qualitatively and quantitatively determined. The polar lipids consisted of 38.4–42.3% of the total lipids. The relative per cent phospholipids based upon the total phospholipids were as follows: phosphatidyl choline, 32.3–33.7%; phosphatidic acid, 24.5–31.7%; phosphatidyl ethanolamine, 15.8–20.9%; phosphatidyl inositol, 12.5–13.0%; phosphatidyl serine, 2.3–5.4%; and diphosphatidyl glycerol, 3.9–4.0%. The relatively high concentration of phosphatidic acid may be characteristic of fungi grown at elevated temperatures. Several sterol glycosides (3.1–6.0%) were present in the polar lipids. The neutral lipids consist of triglycerides, 28.6–36.0%; free fatty acids, 5.3–13.5%; sterols, 11.4–13.9%; sterol esters, 1.8–3.0%; and diglycerides, 2.2–3.4%. The sterols and derivatives comprise an unusually large fraction of the total lipids (16.3–22.9%) suggesting a role in thermostability.     

Lipid composition of ten edible seed species from North Vietnam

The lipid composition and oil content of ten edible seed species from North Vietnam(Cassia tora, Ipomoea aquatica, Raphanus sativus, Citrullus lanatus, Cucumis melo, Cucurbita pepo, Luffa cylindrica, Phaseolus vulgaris, Vigna aurea, Sesamum orientale) have been investigated. The contents of hydrocarbon, triacylglycerol, free fatty acid, sterol, di- and monoglycerol, and polar lipid fractions have been determined with a thin-layer chromatography (TLC)/flame-ionization detection analyzer. Molecular species of hydrogenated triacylglycerols and the fatty acid composition of total lipids also have been analyzed by capillary gas-liquid chromatography. The quantities of major phospholipid classes of four seed species(C. tora, I. aquatica, R. sativus, V. aurea) have been determined by two-dimensional TLC and the spectrophotometrical phosphorus analysis. The fatty acid compositions of nonpolar and polar lipid fractions of these four species also have been analyzed.     

Composition of the neutral and phospholipid fractions from ginkgo nuts (Ginkgo biloba) and fatty acid composition of individual lipid classes

The purified lipid fraction (1.26% on the wet weight basis) from the nuts ofGinkgo biloba was found to be 90.6% neutral lipids, 7.5% polar lipids, and a very small amount of glycolipids. Main fatty acids in the triglyceride fraction were oleic and linoleic acids, and those in the phospholipid fraction were palmitic acid in addition to these unsaturated acids. The enzymic hydrolysis of the triglyceride and individual phospholipid fractions showed that only the triglyceride and phosphatidylcholine fractions contained relatively large amounts of unsaturated acids in their β-positions. The gas liquid chromatography-mass spectrometric analysis of the fatty acids of the steroid ester fraction indicated the presence of lignoceric, cerotic, montanic, and melissic acids as well as a lactone and compounds suspected to be phenolic acids containing long chain diols.     

A comparative study of the phospholipids and fatty acids of some insects

Phospholipids of 27 species of insects representing 6 orders and 20 families were examined by DEAE cellulose column chromatography to determine the choline/ethanolamine phosphoglyceride ratios, and by gas chromatography to determine the constituent fatty acids. The phosphorus in the ethanolamine phosphoglycerides accounted for approximately 50% of the total lipid phosphorus in aphids (Homoptera) and in all but one family of Diptera (flies) examined while the phosphorus in the choline phosphoglycerides accounted for only about 25%. Ethanolamine and choline phosphoglycerides were present in approximately equal proportions in one family of Diptera and in the Coleoptera (beetles) examined. In the other insects examined choline phosphoglycerides predominated, ethanolamine phosphoglycerides comprising only about 25–30% of total lipid phosphorus as they do in most mammalian tissues. Diptera in which ethanolamine phosphoglycerides were the major phosphatides were also characterized by high proportions of fatty acids less than 18 carbons long, particularly palmitoleic acid, in the neutral lipids. Aphids are characterized by a preponderance of 14-carbon fatty acids. The evidence suggests that predominance of ethanolamine phosphoglycerides is associated with a preponderance of shorter chain fatty acids in the neutral lipids. Differences also exist between Diptera and other insects in the fatty acid compositions of different phosphatides, particularly with respect to the distribution of 18-carbon acids. The compositions observed in insects that contained large amounts of the choline phosphoglycerides are similar to those found in vertebrates. Similarities in fatty acid composition of the choline phosphoglycerides in such widely divergent organisms suggest that the fatty acids may play a greater role in phospholipid function than has heretofore been demonstrated. Contribution Number I.P.R.I. 74.