• Ocean and Polar Research
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• 제33권1호
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• pp.35-43
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• 2011

Blubber plays different biological roles in cetaceans, including structural support, physiological demands (thermoregulation, streamlining, buoyancy, etc.), and energy storage. As such, biochemical composition, especially lipid, in the blubber may be vertically stratified in order to effectively assist with these functions. We analysed lipid content, class and fatty acid composition in the blubber of by-catch minke whale (Balaenoptera acutorostrata; n = 11), long-beaked common dolphin (Delphinus capensis; n = 3) and Pacific white-sided dolphin (Lagenorhynchus obiquidens; n = 2) from Korean waters. Lipid content for all three species ranged from 55 to 96% of wet weight, with a dominance of triacylglycerols. Vertical stratification of blubber lipid content was different between species. For minke whale and longbeaked common dolphin, it increased from inner (near the muscle) to outer (near the skin) layer, whereas it decreased for Pacific white-sided dolphin. Thirty-one fatty acids were found in all blubber samples and vertical stratification of fatty acid composition was similar among all three species. Among grouped fatty acids, monounsaturates were the most abundant, gradually increasing from inner to outer blubber layer, whereas polyunsaturates and saturates decreased. Such vertical stratification of lipid content and composition suggests that the modification and accumulation of lipid occur in the blubber itself in order to help cetaceans with their specific physiological needs.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1221-1228
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• 2010

This study aimed to examine the effect of overfeeding on biochemical parameters and lipoprotein-lipase (LPL) mRNA expression in different tissues associated with hepatic lipogenesis in Sichuan white and Landes geese. Fifty healthy male Sichuan white geese and fifty male Landes geese (Cygnus atratus) were hatched on the same day under the same feeding conditions and were selected as experimental animals. After overfeeding for 14 days (from 14 weeks to 16 weeks) and then slaughtering, the biochemical changes of hepatic lipogenesis were evaluated. Results showed that i) in Landes geese, the plasma concentration of glucose was higher (p<0.001), while plasma concentrations of insulin and VLDL were both lower (p<0.01); ii) the LPL mRNA level in pectoralis muscle and leg muscle of the overfed groups in both breeds was higher (p<0.05) than in the control groups; iii) in Sichuan white geese, the proportion of fatty liver weight was positively correlated with plasma triacylglycerols (TG)(p<0.05) and VLDL concentrations (p<0.05), while these correlations were not significant in Landes geese; and iv) the activity of LPL had significant positive correlation with the proportions of lipids in subcutaneous adipose tissue and abdominal adipose tissue in Sichuan white geese, while in Landes geese the correlation was negative (p<0.05) with proportions of lipids in the liver, LPL activity had a significant positive correlation with the proportions of lipids in subcutaneous adipose tissue. These results suggest that the Landes geese have a better ability to use the massive amount of ingested food and to store lipids preferentially in the liver, but the Sichuan white geese have a relatively lower ability to use energetic nutrients and lipid storage is more efficient in the adipose tissues.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1290-1302
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• 2016

Microalgae are being researched for their potential as attractive biofuel feedstock, particularly for their lipid production. For maximizing biofuel production, it is necessary to explore the effects of environmental factors on algal lipid-producing potential. In this study, the effects of nitrogen (N) sources (NO₂-N, NO₃-N, urea-N, NH₄-N, and N-deficiency) and carbon-to-nitrogen ratios (C/N= 0, 1.0, 3.0, and 5.0) on algal lipid-producing potential of Chlorella sp. HQ were investigated. The results showed that for Chlorella growth and lipid accumulation potential, NO₂-N was the best amongst the nitrogen sources, and NO₃-N and urea-N also contributed to algal growth and lipid accumulation potential, but NH₄-N and N-deficiency instead caused inhibitory effects. Moreover, the results indicated that algal lipid-producing potential was related to C/N ratios. With NO₂-N treatment and carbon addition (C/N = 1.0, 3.0, and 5.0), total lipid yield was enhanced by 12.96-20.37%, but triacylglycerol (TAG) yields decreased by 25.52-94.31%. As for NO₃-N treatment, carbon addition led to a 17.82-57.43%/25.86-82.67% reduction of total lipid/TAG yields. When NH₄-N was used as the nitrogen source, total lipid/TAG yields were increased by 46.67-113.33%/28.99-74.76% with carbon addition. The total lipid/TAG yields of urea-N treatment varied with C/N ratios. Overall, the highest TAG yield (TAG yield: 38.75 ± 5.21 mg/l; TAG content: 44.16 ± 4.35%) was achieved under NO₂-N treatment without carbon addition (C/N = 0), the condition that had merit for biofuel production.

• 농업과학연구
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• 제40권4호
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• pp.367-375
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• 2013

The enzymatic interesterification was performed to produce structured lipids (SLs) with palm mid fraction (PMF) and stearic ethyl ester (STEE) for 1, 3, 6, 9, 12 and 15 hr at $80^{\circ}C$. The reaction was catalyzed by Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosus, amount of 20% by weight of total substrates) in a shaking water bath set at 180 rpm. The optimum condition for synthesis of asymmetric SLs were: substrate molar ratio 1:0.5 (PMF:STEE, by weight), reaction time 6 hr, enzyme 20% (wt%, water activity=0.085) of total substrate and reaction temperature $80^{\circ}C$. After reaction at optimized condition, triacylglycerols (symmetrical and asymmetrical TAGs) from reactants were isolated. POP/PPO (1,3-palmitoyl-2-oleoyl glycerol or 1,2-palmitoyl-3-oleoyl glycerol), POS/PSO (palmitoyl-oleoyl-stearoyl glycerol or palmitoyl-stearoyl-oleoyl glycerol), SOS/SSO (1,3-stearoyl-2-oleoyl glycerol or 1,2-stearoyl-3-oleoyl glycerol) were obtained by solvent fractionation. Finally, refined SLs contained stearic acid of 16.91%. Solid fat index and thermogram of the refined SLs were obtained using differential scanning calorimetry. The degree of asymmetric triacylglycerol in the refined SLs was analyzed by Ag-HPLC equipped with evaporated light scattering detector (ELSD). The refined SLs consisted of symmetric TAG of 41.15 area% and asymmetric TAG of 58.85 area%.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.841-846
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• 2014

The present study was conducted to determine whether the two-step time-restricted feeding improves the fattening traits of one-step time-restricted feeding in geese. Thirty-six 8-wk-old geese were allotted into one of three groups. Group R1 (the 1-step restricted feeding group) was allowed access to feed for 2 h in the morning from 8 wk to 14 wk of age. Group R2 (the 2-step restricted feeding group) was treated as Group R1, but was additionally fed for 2 h in the afternoon from 12 wk to 14 wk of age. Group C (the control group) was fed ad libitum from 8 wk to 14 wk of age. Feed intake and body weight (BW) were recorded daily and weekly, respectively. At 14 wk of age, the blood samples were collected to determine the fasting plasma levels of glucose, triacylglycerols and uric acid before sacrifice. The results showed that daily feed intake (DFI) was lower, feed efficiency (FE) was higher in both Groups R1 and R2 than in Group C, and daily gain (DG) in Group R2 was higher than in Group R1 during the whole experimental period (p<0.05). Group R1 exhibited lower abdominal and visceral fat weights in carcass than did Group C (p<0.05), and Group R2 was in intermediate. The fasting plasma glucose levels in Group C were higher, and triacylglycerol levels in Group R1 were higher, compared with the other groups (p<0.05). It is concluded that time-restricted feeding in the fattening period not only increases FE but reduces DFI, and the additional meal during the late fattening period improves the DG without the expense of FE in geese.

• 한국축산식품학회지
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• 제36권2호
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• pp.206-214
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• 2016

The aim of this study was to evaluate the potential use of fatty acids, triacylglycerols, and cholesterol in the detection of adulterated milk fat. The fatty acid, triacylglycerol, and cholesterol profiles of the mixtures of milk and non-milk fat (adulteration ratios of 10%, 30%, 50%, 70%, and 90%) were analyzed by gas chromatography. The results showed that concentrations of the fatty acids with oleic acid (C18:1n9c) and linoleic acid (C18:2n6c), triglycerides with C52 and C54, and cholesterol detected are proportional to the adulteration ratios remarkably. Oleic acid (C18:1n9c), linoleic acid (C18:2n6c), C52, and C54 were lower in pure milk fat than in adulterated mixtures. In contrast, pure milk has a higher cholesterol concentration than all adulterated mixtures (adulteration concentration in the range 10-90%). Thus, we suggest that oleic acid (C18:1n9c), linoleic acid (C18:2n6c), C52, C54, and cholesterol are suitable indicators and can be used as biomarkers to rapidly detect adulterated milk fat by gas chromatography. This study is expected to provide basic data for adulteration and material usage. Moreover, this new approach can detect the presence of foreign oils and fats in the milk fat of cheese and can find application in related studies.

• 한국식품영양과학회지
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• 제32권8호
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• pp.1200-1205
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• 2003

연속식 반응기에서 sn-1,3위치 특이성을 가지는 Rhizomucor miehei lipase(Lipozyme RM IM)를 사용하여 CLA를 함유한 재구성지질을 합성하였다. 옥수수유에 CLA를 transesterification 하기 위한 반응 조건은 연동 펌프의 유속, 반응온도 및 기질의 몰 비율이었다. 연동 펌프의 유속을 변수로 한 실험에서는 유속 1 mL/min, 반응온도 55$^{\circ}C$ 및 1:3 기질몰 비율일 때 재구성지질 중 최대 CLA함량이 10.26 ㏖%을 보였으며, 반응온도를 변수로 한 반응에서는 반응온도가 $65^{\circ}C$일 때 최대 CLA함량 17.33 ㏖%을 나타냈다. 또한 반응 기질의 몰 비율을 변수로 한 재구성지질 합성에서는 1:5몰 비율에서 최대 CLA 함량 17.50 ㏖%을 보였다. Pancreatic lipase analysis 통하여 재구성 지질의 sn-1,3과 sn-2 위치 지방산 조성을 분석하였고 재구성지질의 불포화도를 측정하기 위하여 요오드 값을 측정한 결과 유속 1 mL/min, 반응 온도 55$^{\circ}C$, 몰 비율 1:5 조건에서 120의 실험 조건 내에서 가장 큰 요오드 값을 나타내었다. 한편 각각의 재구성지질 HPLC 분석 결과 99%의 TAG와 1% 이내의 DAG와 MAG가 분석되었다.

• 한국물환경학회지
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• 제32권2호
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• pp.197-204
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• 2016

본 연구는 당화된 도토리의 전분이 미세조류(Chlorella vulgaris) 바이오매스 증식과 바이오오일 함량에 미치는 영향을 알아보고자 하였다. 실험결과 도토리의 전분은 당화 후에 81.3%가 글루코스로 전환되었다. 도토리-글루코스를 이용한 복합영양 상태에서 미세조류는 독립영양 상태보다 높은 바이오매스 증식률과 TAGs (Triacyglycerols)의 함유량을 나타내었는데, 최대 바이오매스 생산량과 TAGs의 함유량은 3 g/L의 도토리-글루코스의 농도에서 각각 12.44 g/L와 32.9%를 나타내었다. 이는 3 g/L의 도토리-글루코스 농도에서 독립영양 상태의 바이오매스 생산량과 비교하면 16.4배의 많은 양의 바이오매스를 생산하였음을 알 수 있었다. 따라서 경제성과 바이오매스의 생산량/생산률 그리고 TAGs의 함유량을 고려한다면 3 g/L의 도토리-글루코스 농도가 미세조류의 증식에 가장 효과적이였다. 본 연구의 결과는 미세조류 유래 바이오에너지의 생산 비용을 절감하는 데 도움이 될 수 있을 것으로 생각된다.

• 미생물학회지
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• 제33권4호
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• pp.237-241
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• 1997

Streptomyces coelicolor A3(2) 배양액의 lipase(EC 3.1.1.3)는 ${\alpha}$-naphthyl-butyrate에 대하여 활성을 나타내어 ${\alpha}$-naphthyl-acetate에 활성을 나타내는 esterase와 구분할 수 있었다. Streptomyces coelicolor A3(2) 세포외 lipase를 Sephadex G-100, DEAE-Cellulose 그리고 Phenyl-Sepharose CL4B 크로마토그래피의 과정을 통해 16% 수율로 15배 분리정제 하였다. SDS-폴리아크릴아마이드 겔 전기영동에서는 34.7 kDa정도의 분자량을 갖는 것으로 나타났다. Tributyrin를 기질로 사용하였을 때 이 lipase의 최적활성조건은 pH 8에서 9 그리고 $37^{\circ}C$였다. 기질로서 triacylglycerol의 지방산 길이가 증가할수록 활성은 감소하였다. A-factor에 의해 lipase활성이 억제되므로 배양초기의 낮은 lipase활성과 관련될 것으로 보인다.

• Molecules and Cells
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• 제43권1호
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• pp.48-57
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• 2020

The microalga Chlamydomonas reinhardtii accumulates triacylglycerols (TAGs) in lipid droplets under stress conditions, such as nitrogen starvation. TAG biosynthesis occurs mainly at the endoplasmic reticulum (ER) and requires fatty acid (FA) substrates supplied from chloroplasts. How FAs are transferred from chloroplast to ER in microalgae was unknown. We previously reported that an Arabidopsis thaliana ATP-binding cassette (ABC) transporter, AtABCA9, facilitates FA transport at the ER during seed development. Here we identified a gene homologous to AtABCA9 in the C. reinhardtii genome, which we named CrABCA2. Under nitrogen deprivation conditions, CrABCA2 expression was upregulated, and the CrABCA2 protein level also increased. CrABCA2 knockdown lines accumulated less TAGs and CrABCA2 overexpression lines accumulated more TAGs than their untransformed parental lines. Transmission electron microscopy showed that CrABCA2 was localized in swollen ER. These results suggest that CrABCA2 transports substrates for TAG biosynthesis to the ER during nitrogen starvation. Our study provides a potential tool for increasing lipid production in microalgae.