• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.218-223
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• 2011

To obtain eicosapentaenoic acid (EPA)-producing bacteria, some 600 strains of bacteria were isolated from Antarctic sediment and marine organisms during the summer expedition of 1999-2000 and 7 EPA-producing bacteria were obtained through screening with TLC and GC. A strain designated as L93 showed the highest EPA production, which was gram-negative, rod-shaped bacterium. L93 strain was identified as Shewanella sp., from the sequence analysis of 16S rDNA. Optimal conditions temperature and pH for the growth and EPA production were about $4^{\circ}C$ and pH 7. In addition, its production was optimized by 50%(w/v) sea salt. We establish the optimal production system to produce about 320 mg per liter by using this optimal EPA production conditions. EPA-methyl ester was purified from cultured L93 strain to a purity of higher than 97% and typical purification yield is greater than 72% of the input amount via urea complexation and HPLC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.407-419
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• 1983

In this study, the lipid components of three species of shellfish included oyster(Crassostrea gigas), top shell(Turbo cornutus) representing salt water shellfish and corb shell(Corbicula fluminea producta) representing flesh water shellfish were analysed and nutriontional significances were discussed. Analysed the total lipid composition, and the fatty acid and sterol composition of total lipid were determined. The lipid was fractionated into three lipid classes neutral, glyco and phospholipid by column chromatography. The fatty acid composition of each lipid class and sterols were determined by gas liquid chromatography. The lipid components of total lipid and neutral lipid were estimated by thin layer chromatography and TLC scanner. The results were as follows: Total lipid contents of shellfish were 1.8% in oyster, 0.4% in top shell and 4.0% in corb shell. The contents of total fatty acid in total lipid were 80.7, 71.2 and 73.2%; and the contents of unsaponifiable matters were 15.4, 18.1 and 23.1% respectively. Total lipids were mainly composed of triglycerides, polar lipid-pigments and sterols as major component, and hydrocarbon-esterified sterols were determined in each sample. The major fatty acids in total lipid were palmitic(37.0%), eicosapentaenoic(13.5%) and linoleic acid(11.2%) in oyster, Octadecatetraenoic(15.8%), palmitic(11.2%), oleic(8.6%) and linoleic acid(8.1%) in top shell, but palmitic(34.0%), linoleic(12.3%) and paimitoleic acid(9.8%) in corb shell. Particularly, the contents of eicosapentaenoic acid of oyster and top shell were higher than those of corb shell. Sterol composition from three species of shellfish were mainly consisted of cholesterol (42.7~64.0%), brassicasterol(15.6~24.7%) and 24-methylenecholesterol (4.7~21.9%). But sitosterol (5.3%) was detected only in oyster and 22-dehydrocholesterol(12.9%) was only in top shell. The contents of fractionated neutral lipid was commonly higher than that of polar lipid in each sample. Glycolipid and phospholipid in polar lipid showed similar in quantity. The neutral lipids were composed of triglycerides(33.0~36.7%), free sterols(25.7~31.2%), esterified sterol(12.4~23.7%) and free fatty acids(5.1~11.7%). The contents of triglycerides and free sterols were higher than those of free fatty acids and esterified sterols. The major fatty acids in neutral lipid were palmitic(28.4~26.4%) eicosapentaenoic(18.6~21.9%) and linoleic acid(9.0~5.4%) in oyster and corb shell but octadecatetraenoic(14.5%), eicosapentaenoic (13.5%) and palmitic acid(12.3%) in top shell. The major fatty acids in glycolipid were eicosenoic(10.2%), palmitic(12.1%) and linolenic acid (10.2%) in oyster, Eicosenoic(26.0%), octadecatetraenoic(14.6.%) and eicosadienoic acid(12.9%) in top shell. But eicosadienoic(21.4%) stearic(14.6%), octadecatetraenoic(8.5%) and eicosenoic acid(8.5%) in corb shell. The major fatty acids in phospholipid were myristic(16.0%), stearic(10.6%), eicosenoic(10.5%) and palmitic acid(10.3%) in oyster, Oleic(22.2%), stearic(20.7%) and linolenic acid (11.8%) in top shell but eicosapentaenoic(25.1%), myristic(8.7%) and arachidonic acid(8.3%) in corb shell.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.501-508
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• 2011

Previous studies suggest that polyunsaturated fatty acids with long carbon chains such as eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) have several health benefits. However metabolic consequences of these fatty acids themselves and their regulation of transcriptional activity involving glucose utilization are not well established. Thus, the purpose of this study was to investigate how EPA influx affects cellular lipid accumulation and gene expressions involving $de$ $novo$ lipogenesis in hepatocyte cultures. Compared to oleic acid treatment, EPA treatment showed remarkably decreased cellular TG conversion and accumulation, along with phospholipids at a lower extent. As expected, EPA increased mRNA expression involving fatty acid influx and lipid droplet formation, but did not affect mRNA expression involving glucose utilization. EPA increased transcriptional activity of PPAR-${\alpha}$ and glucose responsive transcription factor when transcription factor binding protein was activated. Taken together, these data suggest that EPA decreases lipid accumulation through increases of the ${\beta}$-oxidation pathway without interruption of glucose utilization.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.456-463
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• 2021

In this study, the culture conditions for Porphyridium cruentum were optimized to obtain the maximum biomass and lipid productions. The eicosapentaenoic acid content was increased by pH optimization. P. cruentum was cultured with modified F/2 medium in 14-L photobioreactors using a two-phase culture system, in which the green (520 nm) and red (625 nm) light-emitting diodes (LEDs) were used during the first and second phases for biomass production and lipid production, respectively. Various parameters, including aeration rate, light intensity, photoperiod, and pH were optimized. The maximum biomass concentration of 0.91 g dcw/l was obtained with an aeration rate of 0.75 vvm, a light intensity of 300 μmol m-2s-1, and a photoperiod of 24:0 h. The maximum lipid production of 51.8% (w/w) was obtained with a light intensity of 400 μmol m-2s-1 and a photoperiod of 18:6 h. Additionally, the eicosapentaenoic acid and unsaturated fatty acid contents reached 30.6% to 56.2% at pH 6.0.

• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.75-80
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• 1999

The effects of dietary n-3 fatty acids, ${\alpha}$-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6), on brain phospholipid content and fatty acid composition were compared in rats fed with a diet containing constant ratios of saturated fatty acid/monounsaturated fatty acid/polyunsaturated fatty acid (PUFA) and n-3/n-6. The dietary fat in each diet was added at the level of 10%. In each diet, n-3 PUFA comprised two-thirds of the PUFA and the remaining one-third was linoleic acid (18:2). Dietary fat containing linoleic acid as the sole source of PUFA was also given to the control group. The content of brain phospholipid in the three n-3 PUFA groups was significantly lower than that of the linoleic acid group. This reduction was greater in the EPA and DHA groups than in the ${\alpha}$-linolenic acid group. The decrease in phospholipid content in rats fed n-3 fatty acid-rich diets was largely due to the decrease in the phosphatidylethanolamine fraction. Each dietary n-3 PUFA was found to affect the fatty acid composition of brain phospholipids; the most pronounced alteration was observed in phosphatidylethanolamine fraction. Furthermore, the proportion of DHA in the phosphatidylethanolamine fraction tended to be higher in the DHA group than in other PUFA groups. In conclusion, dietary ${\alpha}$-linolenic acid, EPA and DHA can influence the phospholipid content, phospholipid subclass, and fatty acid composition in rat brain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.351-354
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• 2002

The objective of this study was to analyze fatty acid composition in lipids extracted from bullfrogs (Rana catesbeiana Shaw) inhabiting in Korea. Lipid contents in bullfrog legs and bodies were less than 1% (w/w, wet basis) and seasonal variation of the lipid contents was not observed. Lipids in bullfrog legs consisted of 26~31% (w/w) saturated fatty acids, 16~24% monounsaturated fatty acids, and 30~40% polyunsaturated fatty acids. Lipids in bullfrog bodies consisted of 23~28% saturated fatty acids, 29~44% monounsaturated fatty acids, and 16~30% polyunsaturated fatty acids. The major fatty acids in lipids extracted from bullfrogs were palmitic acid, oleic acid, and linoleic acid. Lipids in leg muscles contained 3~8% eicosapentaenoic acid (EPA) and 6~10% docosahexaenoic acid (DHA). Lipids in bodies had 1~3% EPA and 1~3% DHA.

• KSBB Journal
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• v.14 no.1
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• pp.109-113
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• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Nutritional Sciences
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• v.4 no.1
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• pp.26-33
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• 2001

Animal and clinical studies as well as epidemiological data have provided convincing evidence that n-3 polyunsaturated fatty acids can protect against atherosclerosis. However, the effects of the fatty acids on atherogenesis are contradictory. This discrepancy could derive from great susceptibility of the fatty acids to oxidation. We investigated the effect of eicosapentaenoic aced(EPA) on cellular atherogenesis via the scavenger receptor of THP-1 derived macrophages. THP-1 cells were fully differentiated into macrophages by incubating with phorbol 12-myristate 13-acetate for seven days. Atherogenic features of EPA were compared by subsitituting for linoleic acid (LA). Macrophages were also incubated without treatment of the fatty acids as controls. EPA (5-50 nmol/mL) was not cytotoxic and did not measurably induce cellular oxidation compared to bovine serum albumin (BSA) vehicle or identical doses of LA. EPA increased macrophage uptake and degradation of acetylated LDL(AcLDL) up to 14% and 88%, respectively. EPA increased markedly total cellular sterol synthesis and heparin-releasable lipoprotein lipase activity of macrophages, indicating that EPA may enhance accumulation of cellular cholesteryl ester and possibly facilitate formation of foam cells. These results demonstrate that EPA promotes the modified LDL-triggered atherosclerotic process by the modulation of the scavenger receptor and the activation of LPL in macrophages.

• Bioindustry News
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• v.11 no.4
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• pp.54-65
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• 1998

• Journal of Nutrition and Health
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• v.24 no.5
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• pp.420-430
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• 1991

To compare the hypolipidemic effects of n6 linoleic acid. n3 $\alpha$-linolenic acid and n3 eicosapentaenoic acid in rats fed high carbohydrate(70% Cal) diet. male Sprague Dawley rats were fed different experimental diets for 6 weeks. which were different only in fatty acid composition. The dietary fats were beer tallow(BT) as a source of saturated fatty acid (SFA), corn oil(CO) for n6 linoleic acid(LA), perilla oil(PO) for n3 $\alpha$-linolenic acid(LL) and fish oil(FO) for n3 eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA) Plasma total cholesterol(Chol) level was increased by n6 LA but decreased by n3 LL and n3 EPA and most effectively reduced by n3 EPA. HDL-Chol level was raised by n6 LA, but there was no significant change in HDL-Chol levels by n3 LL and was lowered by n3 EPA. Plasma TG level was reduced by n6 LA, but lipogenesis in liver was not affected by n6 LA. However, plasma TG level was lowered by n3 LL and EPA. Both lipogenic enzyme activity and liver TC level were also decreased by n3 PUFA. The relative proportions of TG in VLDL was significantly lowered by n3 EPA. but the proportions of Apo B in VLDL was not changed by n3 EPA. Overall. the hypolipidemic effect was in the order of EPA+ DHA(n3) >LL(n3) >LA(n6) and fish oil and perilla oil rich in n3 PUFA may have important nutritional applications in the prevention and treatment of hypertriglyceridemia.