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1.
Minimal deviation hepatoma cells were cultured in a modified Swim's 77 medium supplemented with decreasing amounts of serum,
lipid-free serum, and lipid-free serum containing added palmitic or linoleic acids. Cellular phospholipids were extracted
and the class distribution determined quantitatively. The fatty acid composition of each phospholipid class was determined,
and the percentages from cells grown on each of the various media were compared. Cellular phospholipid class and fatty acid
compositions differed from media compositions, indicating that intact serum phospholipids are not incorporated into cellular
structures. Phosphatidylcholine percentages decreased as the media serum and lipid levels decreased, while phosphatidylinositol
and phosphatidylethanolamine percentages increased. Sphingomyelin of cells grown in medium containing added linoleic acids
contained a high level of a 24∶2 acid. All classes, except sphingomyelin, contained elevated levels of 18∶1 acid and decreased
levels of polyunsaturated fatty acids, relative to normal rat liver. Cells cultured on lipid-free medium did not contain increased
concentrations of 20∶3 acid, suggesting that this hepatoma cell cannot desaturate monoenoic acids. Phosphoglycerides of cells,
grown on lipid-free medium, had the highest monoene fatty acid concentration, whereas those cells grown on media containing
added linoleic acid had the lowest concentrations, suggesting that linoleate may inhibit or regulate monoenoic acid biosynthesis
in this cell. These mass data also demonstrate that monoenoic fatty acid biosynthesis in this cultured hepatoma cell responds
to dietary changes. 相似文献
2.
Minimal deviation hepatoma 7288C cells were cultured in a modified Swim's medium supplemented with decreasing levels of serum,
lipid-free serum, lipid-free serum plus fatty acids, and other additives. Cellular and media neutral lipid classes were quantitated,
the fatty acids of triglycerides and sterol esters analyzed, and the carbon number distribution of triglycerides determined.
Cellular triglyceride biosynthesis virtually was inhibited when the medium was supplemented with bovine serum alone. This
inhibition was not observed when the medium was supplemented with fetal calf serum alone or mixtures of fetal calf serum and
bovine serum. Cells cultivated on medium supplemented with lipid-free serum plus palmitic or linoleic acids had much lower
levels of free and esterified cholesterol. The fatty acid composition of cellular triglycerides and cholesterol esters differed
dramatically from the corresponding media lipid classes. Except when linoleic acid was added to the medium, changes in the
media serum and lipid levels had only marginal effects upon the fatty acid composition of cellular triglycerides and cholesterol
esters. These data, in conjunction with earlier data that showed the media neutral lipid levels did not decrease during cell
growth, indicate that these hepatoma cells utilize little or no serum triglycerides and cholesterol esters. Linoleic acid
added to the medium dramatically reduced the level of 18∶1 acids in cellular triglycerides and cholesterol esters. Palmitic
acid added to the medium did not change the fatty acid compositions significantly. Comparison of experimentally determined
and calculated triglyceride carbon number percentages indicated a random distribution of fatty acids in this glyceride. The
fatty acid composition of cellular triglycerides was similar to the composition of the cholesterol esters. The lack of characteristic
and distinguishable compositions of these two classes that occur in most normal tissues suggests a loss of specificity in
the lipid metabolism of this neoplasm at the class level. 相似文献
3.
Minimal deviation hepatoma 7288 C cells were cultured on media containing 25% serum to the confluent stage. The growth media was replaced with serumfree media containing 1-14C-palmitate, and incubations were continued for 0.75, 1.5, 3, 6, 12, and 24 hr. The distribution of radioactivity among the major neutral lipids and phosphoglycerides was determined for cells and culture media. Radioactivity in individual fatty acids of cellular triglyceride, phosphatidylcholine, and phosphatidylethanolamine also was determined. After 24 hr, more than 95% of the administered radioactivity was recovered in neutral and phosphoglycerides, indicating that only a small amount of the fatty acid was oxidized. At any time period examined, over 80% of the incorporated radioactivity was found in triglyceride, phosphatidylcholine, and phosphatidylethanolamine. Incorporation of the label into cellular triglyceride and phosphatidylcholine plateaued at 12 hr, whereas incorporation of radioactivity into phosphatidylethanolamine still was increasing at 24 hr. In contrast, during the entire incubation period the relative distribution of14C among esterified lipid classes in the culture media remained constant. Elongation of palmitic acid to stearic acid and its subsequent desaturation to oleic acid suggests that these cells possess an active elongation and monoenoic desaturation system. Labeled glycerol ether diesters were not detected in the cells or culture media. Positional distribution of the14C label in the triglyceride and phosphatidylcholine suggests that minimal deviation hepatoma cells do not exhibit diglyceride selectivity in the biosynthesis of these two lipid classes. 相似文献
4.
Randall Wood 《Lipids》1982,17(11):763-770
Groups of rats were fed a fat-free diet supplemented with 0.5% safflower oil (control) or the control diet containing 0.5%
of 5,8,11,14-eicosatetraynoic acid (TYA). Blood was collected weekly and plasma lipids analyzed. After 4 weeks, the animals
were killed and the liver lipids were analyzed in detail. The acetylenic fatty acid perturbed plasma neutral lipid and phospholipid
class concentrations and reduced growth rates. Liver triglyceride concentrations were reduced dramatically in the TYA fed
animals, suggesting interference with complex lipid synthesis. Plasma and liver triglycerides were shifted to higher molecular
weight species suggesting that TYA affected fatty acid metabolism. The phospholipids showed an accumulation of 18∶2 and a
fall in 20∶4 percentages indicating an inhibition in the conversion of linoleate to arachidonate. All major lipid classes
exhibited an increase in 18∶1 levels. Analysis of the octadecenoate positional isomers indicated the proportion of oleate
increased substantually in all lipid classes whereas vaccenate proportions had fallen dramatically. All of the data collectively
suggest that TYA inhibits the elongation of unsaturated fatty acids. A group of rats bearing hepatoma 7288CTC were also fed
the TYA diet. Host liver lipids were affected by TYA similar to normal TYA fed animals, but the effects on hepatoma lipids
were marginal. 相似文献
5.
Studies are reported on the composition of the lipids of human liver and hepatoma tissues from male adults. Liver tissues
were obtained from individuals who died from causes other than liver disease or cancer. The hepatoma tissues were obtained
from individuals shortly after they succumbed to cancer. The total lipid of each tissue was fractionated quantitatively by
silicic acid column chromatography into neutral lipid, glycolipid, and phospholipid fractions. These fractions were analyzed
by thin layer chromatography and converted to methyl esters for analysis of their constituent fatty acids by gas liquid chromatography.
In comparison to liver tissue, the total amount of lipid in the hepatoma tissues was generally higher and more variable; the
lipid of one hepatoma was ca. 92% of the dry wt of the tissue. The greater lipid content of the hepatoma tissues was due to
the high percentage of neutral lipid. Except for one specimen, there was ca. the same amount of glycolipid in the hepatoma
as in the liver tissues, but the composition of the glycolipid fraction of the hepatoma lipid differed considerably, particularly
in the ganglioside fraction. The phospholipid fraction of hepatoma lipid was much lower than that of liver but exhibited only
quantitative differences in composition. No glyceryl ether diesters and only traces of plasmalogens of phosphatidyl choline
or phosphatidyl ethanolamine were detected in the liver and hepatoma lipids. The levels of monoenoic acids were higher and
those of linoleic and polyunsaturated fatty acids lower in the hepatoma lipids. Positional isomers of trienoic acids not normally
present in liver tissue were detected in hepatoma lipids. The abnormalities observed in lipid composition indicated interferences
in the regulatory processes of lipid metabolism in human hepatoma similar to those observed in animals. 相似文献
6.
The detailed composition of cellular lipid of more than 23 species of yeast has been determined quantitatively by thinchrography
on quartz rods, a method previously used for estimating cellular lipids of seven species of yeast. That data was fortified
by neutral and phospholipid quantitations on 30 species of yeast cells. Most of the test organisms contained 7–15% total lipid
and 3–6% total phospholipid per dry cell weight, except for the extremely high accumulation of triglycerides in two species
ofLipomyces. Qualitatively, 30 species of yeast cells contained similar neutral lipid constituents (triglyceride, sterol ester, free
fatty acid, and free sterol) and polar lipid components (phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine,
phosphatidyl inositol, cardiolipin, and ceramide monohexoside) without minor constituents. Based on the quantitative composition
of neutral lipids, the 30 species of yeast were divided into two groups, the triglyceride predominant group and the sterol
derivative group. These groupings were fairly well overlapped from the standpoint of the distribution characteristics of fatty
acid. The relative polar lipid compositions also grossly resembled each other. Only one exception of polar lipid composition
in yeast cells was found inRhodotorula rubra species which contained phosphatidyl ethanolamine as the most abundant phospholipid. Fatty acid distribution patterns in
yeast cells consistently coincided with other reports concerning fatty acid composition of yeast cells. Correlation of lipid
composition and classification of yeasts are suggested and discussed.
A part of this investigation has been reported at the 14th conference of the Japan Oil Chemists' Society, Nagoya, Japan, October
1975. 相似文献
7.
Bacillus megaterium QM B1551 spore lipids were extracted by an improved technique, and the phospholipid and fatty acid compositions were determined.
Phospholipids accounted for 65% of the total fatty acids; the neutral lipid fraction contained 15% and the remaining fatty
acids were in the interphase, aqueous phase and pellet from the lipid extraction. Each phospholipid had similar fatty acid
compositions as did the delipidated pellet. However, the aqueous phase and, to some extent, the interphase had unique fatty
acid compositions. Also, fatty acids were found acylated to proteins, which was observed by electrophoresis of delipidated
proteins from spores grown in [1-14C]palmitate. Therefore, spores contain unique non-phosphatide fatty acid components that can now be analyzed. 相似文献
8.
Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver
and hepatoma 72288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity.
Hepatoma NADH: cytochrome C reductase and 5′-nucleotidase exhibited abnormal subcellular distributions.
The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by
elevated percentages of diphosphatidylglycrerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular
fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong
complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedlg from liver and, unlike liver, did
not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while
others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower
percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual
phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate
were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions,
contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some
acyl moieties for the biosynthesis of various hepatome lipid classes differs from liver sources. The possible changes in acyl
pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species
that could contribute to the abnormal properties of the hepatoma membranes. 相似文献
9.
Culex quinquefasciatus andCulex tritaeniorhynchus cells were grown in spinner culture medium. The cells were harvested at late logarithmic and stationary phases of growth.
The total lipid, total neutral lipid, and total phospholipid contents of the cells were analyzed to determine changes that
occurred in the fatty acid profiles of the lipids with aging and between species. There was an increase in the amount of total
neutral lipids with a corresponding decrease in amount of total phospholipid from logarithmic to stationary phases of growth
of theCulex quinquefasciatus cells. Chain elongation and/or desaturation of acids occurred with aging of cells. The fatty acids of the phospholipids had
a longer average chain length than the neutral lipids. 相似文献
10.
Minimal deviation hepatoma 7288 C cells were cultured in Swim's medium containing 10% serum for 48 hr. The growth medium was replaced with serum free media containing different concentrations of [1-14C] eicosa-8,11,14-trienoic acid and the cells were incubated for 24 hr. Incorporation into cell lipids, oxidation to CO2, and desaturation to arachidonic acid were studied. The oxidation of the acid was very low. It was preferentially incorporated into the polar lipids of the cell. The incorporation depended on the number of cells and fatty acid concentration. Saturation of the cells with the acid was reached when 144.7 nmoles per mg of cellular protein were incorporated. The acid was desaturated readily to arachidonic acid. The nmoles of eicosatrienoic acid converted to arachidonic acid per mg of cellular protein were hyperbolic function of the acid incorporated. Maximal desaturation, 23 nmoles per mg of cellular protein, was reached when the cells were saturated with the acid. The calculations of the desaturation capacity and of the endogenous pool of eicosatrienoic acid available for desaturation in the cell are discussed. 相似文献
11.
Richard C. Crain 《Lipids》1982,17(12):935-943
A protein that accelerates transfer of phospholipids of varying head group and fatty acid composition has been purified from
bovine liver. As previously found for other phospholipid transfer proteins, “nonspecific lipid transfer protein” stimulates
a kinetically biphasic transfer of radioactively labeled phospholipid from small unilamellar vesicles to unlabeled multilamellar
vesicles. The kinetics are consistent with rapid transfer of phospholipid from the outer monalyer and slow transfer of that
localized in the inner monolayer (half-times greater than 3 days for phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol).
Protein catalyzed transfer is inhibited by high ionic strength and has an activation energy of 35 kJ/mol. The broad lipid
specificity and ease of large-scale purification make these proteins candidates for membrane phospholipid compositional modification.
The compositions of rat liver mitochondrial and microsomal membranes and Morris hepatoma 7288c mitochondrial membranes were
altered by incubation with lipid vesicles and nonspecific lipid transfer protein. Incubation with phosphatidylcholine vesicles
led to increased levels of phosphatidylcholine and decreased levels of other transferrable lipids (phosphatidylethanolamine,
phosphatidylinositol, and cholesterol) unless the latter were included in the vesicles. When vesicles containing dipalmitoylphosphatidylcholine
were incubated with microsomal membranes, a large increase in disaturated phosphatidylcholine was also observed. These changes
in composition were correlated with activities of membrane enzymes. It appears that microsomal glucose-6-phosphatase is inhibited
by increased phosphatidylcholine saturation. Moreover, this enzyme is also inhibited by decreases in the phosphatidylethanolamine/phosphatidylcholine
ratio whereas NADPH cytochrome c reductase is not. Likewise, decreased cholesterol to phospholipid ratios did not greatly
affect the abnormally low levels of hepatoma succinate cytochrome c reductase activity.
This paper was presented at the 73rd AOCS annual meeting, Toronto, Canada, May 1982. 相似文献
12.
Monoenoic acid fractions were isolated from phosphatidylcholines, phosphatidylethanolamines, triglycerides, and cholesterol
esters derived from minimal deviation hepatoma 7288C cells cultured on 11 media containing varying levels of serums and lipids.
Hexadecenoate (16∶1), octadecenoate (18∶1), and eicosenoate (20∶1) fractions were subjected to ozonolysis and the isomeric
composition of the monoene fractions determined quantitatively by gas liquid chromatography. The 16∶1 fractions consisted
of palmitoleic acid, the Δ9 isomer (85–90%), and the Δ11 isomer (10–15%) in most of the cases; growth media and lipid class
origin had little effect upon composition. The predominate acids of the 20∶1 fraction were the Δ13 and Δ11 isomers. Generally,
the Δ13 isomer was present in the highest concentration, and this isomer was higher in phosphatidylcholines than the other
classes. Vaccenic acid represented 33–66% of the 18∶1 fraction, and the balance was oleic acid. Oleic acid concentrations
decreased, and vaccenic acid levels increased as the growth medium serum and lipid levels decreased. Lipid classes did not
exhibit any distinct preference for either isomer. These data represent the first quantitative isomeric analysis of monoenoic
acids derived from individual lipid classes and are the first to show the occurrence of high levels of vaccenic acid in neoplastic
cells. This study suggests that the elevated levels of oleic acid, one of the most frequently observed changes in tumor lipids,
may, in fact, represent elevated levels of vaccenic acid. 相似文献
13.
The lipid composition of Yoshida ascites hepatoma cells was analyzed together with that of ascitic plasma and of livers and
blood plasma from host and normal rats. In comparison to normal livers, host livers showed no significant differences in the
content of the various lipid classes, but contained a higher percentage of palmitic acid and a lower proportion of arachidonic
acid in the major phospholipid classes. In addition, tumor growth induced a marked hypertriglyceridemia in host animals; changes
in the concentration of other plasma lipid classes were not statistically significant. The ascitic plasma contained small
amounts of lipids mainly constituted by cholesteryl esters and phospholipids. Yoshida hepatoma cells contained less phospholipids
in comparison to both host and normal liver, while the increased level of triglycerides and the decrease of free fatty acids
were not statistically significant. Hepatoma cells showed appreciable amounts of ether-linked lipids associated in part to
neutral lipids (as glyceryl ether diesters) and, in part, to ethanolamine and choline phosphoglycerides. The alkyl groups
in GEDE as well as in ethanolamine and choline phosphoglycerides were mainly constituted by C16∶0 and C18∶0 followed by C18∶1. The alk-1-enyl groups in ethanolamine and choline phosphoglycerides were C16∶0 and C18∶0 with only a minor proportion of C18∶1. In comparison to both host and normal liver, Yoshida hepatoma cells showed significant changes in the fatty acid composition
of neutral lipids and phospholipids. Some of the major changes consisted of an increase of monoenoic acids associated with
a decrease of arachidonic and docosahexaenoic acids in phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol. 相似文献
14.
The lipid class and fatty acid composition profiles of mammary glands of female rats fed a nutritionally adequate diet are compared to those of tumors induced in the mammary glands by intravenous injection of dimethylbenz(a)anthracene of animals fed the same diet. Ca. 95% of the lipids of the mammary glands of the control group of animals consisted of triglycerides; glycolipids and phospholipids were present in only minor amounts. In contrast, the lipids of the mammary tumors contained much lower amounts of neutral lipids and higher concentrations of phospholipids. The glycolipid fraction was a minor component of both tissues but differed greatly in composition. The composition of the phospholipid and neutral lipid fractions, particularly the latter, of the mammary tumors also differed from that of the mammary glands of the control animals. The neutral lipids of the tumor tissues contained elevated levels of free fatty acids and cholesterol and much lower concentrations of triglyceride compared to the mammary gland lipids. Differences also were observed in the fatty acid composition of tumor and mammary gland lipid. The greatest differences occurred in the concentrations of polyunsaturated fatty acids which were generally much higher in the tumor lipids. 相似文献
15.
Fatty acids ofSterculia foetida were added to the medium used to maintain the Morris hepatoma 7288C in culture. The effect of this supplement on the lipid
composition was examined. Overall, monoene levels were decreased with 18∶1 levels reduced by 40%. Saturated fatty acid levels
were increased, with stearate (18∶0) levels 220% of control values. No effect occurred on the level of polyunsaturates (18∶2,
20∶4, 22∶5, 22∶6). These changes in fatty acid makeup were observed in both neutral and phospholipid fractions, and all lipid
classes were affected. Triglycerides were most affected with a 66% decrease in 18∶1. There appeared to be little specificity
of effect in the phospholipids with 18∶1 levels decreased 40–60% in all classes. All classes were therefore dependent on an
endogenous supply of 18∶1. Examination of the distribution of geometrical isomers of 18∶1 reveals that in all lipid classes,
except diphosphatidylglycerol (DPG), the ratio of Δ11 to Δ9 isomer decreased toward the isomeric distribution displayed by
total medium lipids. In DPG, although 18∶1 levels were lowered, the isomeric distribution increased. DPG, synthesized and
found in the mitochondria, may use a separate pool of 18∶1 during synthesis. Cyclopropene fatty acids (sterculic and malvalic)
were incorporated into both neutral and phospholipid fractions with preferential incorporation into triglycerides. Cyclopropene
fatty acids were not selectively incorporated into any phospholipid species. Sphingomyelin did not incorporate cyclopropene
fatty acids, indicating that a different class of acyltransferase is used in the formation of this phospholipid class. 相似文献
16.
Several studies are presented which indicate that composition of cell lipid is regulated by interaction between intracellular
metabolism and lipid transport processes. When the fatty acid composition of cells cultured in essential fatty acid deficient
conditions was studied, activation of synthesis of unusual polyun-saturated fatty acids was observed for a number of cell
lines. In addition cells contained persistent residual amounts of linoleic acid, presumably owing to efficient scavenging
mechanisms. The source of cell lipids was studied in both chemically defined and serum-supplemented media. In the absence
of exogenous lipid, cells synthesize lipids from simple precursors, a process which is inhibited by adding serum. When serum
lipid is present, cells preferentially utilize fatty acids as a source of nonsterol lipid. These are subsequently esterified
intracellularly to make glycerides and phospholipids. When triglyceride is utilized as a source of cell lipid, it is first
hydrolyzed before being taken up. By use of a nonhydrolyzable cholesterol ester analog, it is confirmed that both free and
ester cholesterol are taken up and excreted by cells. Intracellular cholesterol content is thus regulated by rates of uptake,
hydrolysis and excretion as well as by biosynthesis.
One of 13 papers presented at the symposium “Lipid Metabolism in Cells in Culture,” AOCS Meeting, Houston, May 1971. 相似文献
17.
The concentrations of the major neutral lipid and phospholipid classes in the plasma of rats bearing hepatoma 7288CTC were
determined at various times after transplantation. The fatty acid composition of each lipid class was also analyzed quantitatively
as tumor growth progressed. Generally, most lipid classes exhibited a slight decrease between the third and sixth day after
transplantation, returned to near normal levels by the 15th day, increased dramatically and peaked between the 24th and 27th
days before plummeting sharply. At peak concentrations, triglycerides were increased 5 times the normal levels, whereas cholesterol,
cholesteryl esters and phosphatidylcholines were increased 3-fold. The percentage of hexadecenoates decreased in all lipid
classes as tumor growth progressed and generally, stearate levels increased. In addition to monounsaturated fatty acids, lysophosphatidylcholines
and phosphatidylcholines showed relatively large decreases in the percentages of polyunsaturated fatty acids with increased
tumor growth. These results indicate that hepatoma 7288CTC can cause perturbation of host animal plasma lipids in the early
stages of growth which precedes the massive hyperlipidemia. The interpretation of these results suggests that the early changes
in plasma lipids may result from alterations in the normal lipid metabolism of the host, and the hyperlipidemia that develops
later may result from the mobilization of lipids to compensate for the altered metabolism.
This paper was given by M. Matocha as an Honored Student Award presentation at the AOCS meeting, San Francisco, CA, April
29–May 31, 1979. This work has been submitted in partial fulfillment of the requirement for the M.S. degree. 相似文献
18.
Embryonic vs tumor lipids: II. Changes in phospholipids of developing chick brain,heart, and liver 总被引:1,自引:0,他引:1
Randall Wood 《Lipids》1974,9(6):429-439
Brain, heart, and liver tissues were excised from embryos and chicks 10, 13, 16, 19, 22, 27, and 53 days after incubation
was initiated and the lipids extracted. The quantitative distribution of the phospholipids and the fatty acid composition
of the individual phosphatides were determined for each time period. Each tissue exhibited a distinct phospholipid composition
that differed from the composition of egg. Elevated concentrations of particular phosphoglycerides that characterize certain
mature tissues were observed at the earliest time period. As development progressed, some phospholipid classes in all tissues
showed dramatic change, while others remained relatively constant. Brain showed the most stable composition, while the phosphatides
of liver were the most dynamic. Each phospholipid class exhibited a characteristic fatty acid profile that was unique for
each tissue. All of the phospholipid classes showed a change in fatty acid composition as development progressed, and, in
some tissue, the change was dramatic. The fatty acid composition of brain phosphoglycerides showed the least change, while
liver showed the greatest fluctuation. Docosahexaenoic acid and, in most cases, arachidonic acid decreased in the phosphoglycerides
with increased development. The decrease in docosahexaenoic acid correlated well with the decreasing mitotic indices of heart
and liver cells as development progressed. Comparison of observed abnormal lipid patterns between mature and neoplastic tissue
with embryonic tissue lipid profiles suggest that some of the observed abnormalities of neoplasms probably are due to changes
in lipid metabolism associated with rapidly proliferating cells, whereas other abnormalities appear to be associated with
neoplasia. 相似文献
19.
The total lipids, total neutral lipids, and total phospholipids fromAedes aegypti andAedes albopictus cells cultivated in vitro in a medium containing fetal calf serum were analyzed. The mosquito cells were harvested in the logarithmic and stationary phases of growth. The fatty acid profiles of the lipids showed differences during the aging of the cells but not between species. There was an increase in chain elongation and unsaturation of the fatty acids in the stationary phase when compared with the logarithmic phase of growth. The major components of the fatty acid profiles of the cells were 16∶1, 16∶1, and 18∶1 fatty acids. Few similarities were found between the lipid analysis of the mosquito cells and the growth medium. 相似文献
20.
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. 相似文献