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1.
Dong-Hoon Kang Eun-Jin Jeh Jeong-Woo Seo Byung-Hee Chun Byung-Ki Hur 《Korean Journal of Chemical Engineering》2007,24(4):651-654
This study attempted to characterize the effects of NaCl and MgSO4 as the primary components of sea salt affecting the yields of production of polyunsaturated fatty acids (PUFAs) by Thraustochytrium aureum ATCC 34304. Reductions in the NaCl concentration of the culture medium suppressed the formation of palmitic acid (PA, C16:
0) but enhanced the production of PUFAs, which induced an increase of the concentration of docosahexaenoic acid (DHA, C22:
6) up to 46.65% from 44.26%. MgSO4 revealed a similar, yet more highly significant, effect on the fatty acids profile than NaCl. The yields of PUFAs and DHA
showed maximum values such as 67.10% and 49.47%, respectively, at the concentration of 10 g L−1 for NaCl and 0 g L−1 for MgSO4. However, the quantities of mono-and diunsaturated fatty acids, oleic acid (OA, C18: 1) and linoleic acid (LA, C18: 2) at
the same concentrations, were compared with those of normal culture medium. Additionally, it was investigated that the increase
of culture temperature reduced PUFAs contents but the reductions were recovered by the removal of MgSO4 form the culture medium, which showed that concentration of salts and culture temperature affected independently the production
of PUFAs in T. aureum. 相似文献
2.
Debasish Pal Dipankar Banerjee Tarun K. Patra Amarendra Patra Amitabha Ghosh 《Journal of the American Oil Chemists' Society》1998,75(10):1373-1378
The sting ray, Dasyatis bleekeri (Blyth), has been studied for lipids and fatty acids of its liver. The neutral lipids identified were hydrocarbons, wax esters,
steryl esters, 1-O-alkyl-2,3-diacylglycerols, triacylglycerols, and sterols. Neutral lipids were predominant (91.8%), major components being
triacylglycerols (92.7%). Polyenoic fatty acids of n-3 series, viz. eicosapentaenoic acid and docosahexaenoic acid, were high in the phospholipid and neutral lipid fractions. Cholesterol was
the major component (67.9%) in the steryl ester fraction. Glyceryl ethers, with chainlengths up to 30 carbons, were recorded
with unsaturated, anteiso, iso, and normal chains. In wax ester alcohols, up to 32-carbon chains were recorded. Hydrocarbons
were up to 36-carbon chains with anteiso, iso, and normal chains. Among branched chain hydrocarbons, pristane was the major
component (6.7%) and squalene was present at the level of 3.5%. Chimyl and batyl alcohol backbones were the major components
found in 1-O-alkyl-diacylglycerols. 相似文献
3.
The effects of temperature and temperature shift on the fatty acid composition and docosahexaenoic acid (DHA, C22∶6n−3) content
and productivity of the marine microalga Crypthecodinium cohnii ATCC 30556 were investigated. The microalga grew well over the entire range of temperatures (15–30°C) studied. High temperature
favored the growth of the microalga with the highest specific growth rate of 0.092 h−1 at 30°C. In contrast, low temperature favored the formation of polyunsaturated fatty acids. The highest DNA content was obtained
at 15°C in the early stationary phase (i.e., 72h). In order to achieve high DHA productivity, a shift from high temperature
to low temperature at a later stage of cultivation (i.e., 48h) was also attempted. A temperature shift from 25°C (for 48 h)
to 15°C (for 24 h) resulted in an increase in cellular DHA content by 19.9% and productivity by 6.5% as compared to that maintained
at 25°C (for 72 h). 相似文献
4.
Gudmundur G. Haraldsson Björn Kristinsson Ragnheidur Sigurdardottir Gudmundur G. Gudmundsson Harald Breivik 《Journal of the American Oil Chemists' Society》1997,74(11):1419-1424
The objective of this study was to investigate the use of lipases as catalysts for producing concentrates of eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA) from fish oil as an alternative to conventional chemical procedures. Transesterification
of fish oil with ethanol was conducted under anhydrous solvent-free conditions with a stoichiometric amount of ethanol. Among
the 17 lipases tested, the results showed that Pseudomonas lipases had the highest activity toward the saturated and monounsaturated fatty acids in the fish oil, much lower activity
toward EPA and DHA and, at the same time, good tolerance toward the anhydrous alcoholic conditions. With 10 wt% of lipase,
based on weight of the fish oil triacylglycerol substrate (15% EPA and 9% DHA initial content), a 50% conversion into ethyl
esters was obtained in 24 h at 20°C, in which time the bulk of the saturated and monounsaturated fatty acids reacted, leaving
the long-chain n-3 polyunsaturated fatty acids unreacted in the residual mixture as mono-, di-, and triacylglycerols. This
mixture comprised approximately 50% EPA+DHA. Total recovery of DHA and EPA was high, over 80% for DHA and more than 90% for
EPA. The observed fatty acid selectivity, favoring DHA as a substrate, was most unusual because most lipases favor EPA. 相似文献
5.
Eun-Jin Jeh Rangarajulu Senthil Kumaran Byung-Ki Hur 《Korean Journal of Chemical Engineering》2008,25(5):1103-1109
The heterotrophic marine protist, Thraustochytrium aureum produces substantial amounts of polyunsaturated fatty acids (PUFAs). In the present investigation, changes in the lipid and
fatty acid profiles of T. aureum were studied according to the culture age. T. aureum was grown in artificial sea water medium for 10 days at 25 °C in shake culture condition. One to 10 day old cell samples
were analyzed for cell biomass production, total lipid content, fatty acid profile and lipid body formation. In all the samples
tested, total lipid production was found to be directly proportional to the dry cell weight of T. aureum. In the early phase of cell growth, cell biomass production, lipid content and glucose consumption were found to be higher.
Thin layer chromatographic analysis (TLC) of lipids showed the presence of triacylglycerol (TAG; 169 mg/g, 90%), phospholipids
(PL; 83 mg/g, 66%) and sterol (ST; 6 mg/g, 5%), which were recorded at maximum levels in the early growth phase of the cells.
The composition of PUFAs and saturated fatty acids (SFAs) of the cell biomass and lipid class components (TAG and PL) was
identified by gas chromatographic analysis (GC). In the early phase of cell growth, production of PUFAs in the total fatty
acids was found to have attained maximum levels (61.3%) in which docosahexaenoic acid alone showed higher content of occurrence
(99.0 mg/g in total lipid; 65.2 mg/g in TAG and 41.0 mg/g in PL). In the middle phase of cell growth, palmitic acid production
was found to be higher (36.7 mg/g in total lipid; 31.3 mg/g in TAG and 12.6 mg/g in PL). Transmission electron microscopic
studies of the cells showed the presence of a membrane around the lipid bodies in the early phase of cell growth. TAG and
PL were actively involved in the formation of lipid bodies in the cells of T. aureum. Large-sized lipid bodies accumulated in 3 day old cells which were then fragmented into smaller bodies in the late growth
phase. 相似文献
6.
Preparation of highly purified concentrates of eicosapentaenoic acid and docosahexaenoic acid 总被引:1,自引:9,他引:1
Harald Breivik Gudmundur G. Haraldsson Björn Kristinsson 《Journal of the American Oil Chemists' Society》1997,74(11):1425-1429
Because of the complexity of marine lipids, polyunsaturated fatty acid (PUFA) derivatives in highly purified form are not
easily prepared by any single fractionation technique. The products are usually prepared as the ethyl esters by esterification
of the body oil of fat fish species and subsequent physicochemical purification processes, including short-path distillation,
urea fractionation, and preparative chromatography. Lipase-catalyzed transesterification has been shown to be an excellent
alternative to traditional esterification and short-path distillation for concentrating the combined PUFA-content in fish
oils. At room temperature in the presence of Pseudomonas sp. lipase and a stoichiometric amount of ethanol without any solvent, efficient transesterification of fish oil was obtained.
At 52% conversion, a concentrate of 46% eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) was obtained in excellent
recovery as a mixture of mono-, di-, and triacylglycerols. The latter can be easily separated from the saturated and monounsaturated
ethyl esters and converted into ethyl esters either by conventional chemical means or enzymatically by immobilized Candida antarctica lipase. Urea-fractionation of such an intermediary product can give an EPA+DHA content of approximately 85%. 相似文献
7.
This study focused on the use of pressurized CO2 as a reaction medium for the enrichment of docosahexaenoic acid (DHA) from tuna oil fatty acids via lipase-mediated esterification. Of the three lipases tested, Lipozyme RM IM from Rhizomucor miehei was selected for further study. Enzyme loading, water addition, and reaction time were also explored. Near-supercritical CO2, prepared at 25 °C and 8.3 MPa, was the most effective reagent tested for enriching DHA from the residual fatty acid fraction. In addition to near-supercritical CO2, optimal conditions included addition of 0.2 wt% (based on total substrates) water, enzyme loading of 5 wt% (based on total substrates), and a reaction time of 18 h. The DHA concentration and recovery yield for the residual fatty acid fraction under these optimal conditions were 75.8 wt% and 81 wt%, respectively. 相似文献
8.
T. Yaguchi S. Tanaka T. Yokochi T. Nakahara T. Higashihara 《Journal of the American Oil Chemists' Society》1997,74(11):1431-1434
The culture conditions for high-yield production of docosahexaenoic acid (DHA) by Schizochytrium sp. strain SR21 were investigated in a fermenter. With increasing carbon (glucose) and nitrogen (corn steep liquor and ammonium
sulfate) sources (up to 12% glucose) in the medium, DHA productivity increased without a decrease in growth rate, i.e., 2.0,
2.7, and 3.3 g DHA/L/d with 6, 10, and 12% glucose, respectively. Eventually, 48.1 g dry cells/L and 13.3 g DHA/L were produced
in 4 d with 12% glucose. DHA productivity was decreased with 15% glucose, i.e., 3.1 g/L/d. With 12% glucose, the lipid content
was 77.5% of dry cells, and DHA content was 35.6% of total fatty acids. The lipid was composed of about 95% neutral lipid
and 5% polar lipid. In polar lipids, the contents of phosphatidylcholine (PC), phosphatidylethanolamine, and phosphatidylinositol
were 74, 11, and 5%, respectively. The PC profile was simple, 70% of PC molecules were 1-palmitoyl-2-DHA-PC and 1.2-di-DHA-PC.
These results indicate that Schizochytrium sp. strain 21 is an excellent source for microbial DHA production, including not only the acid form of DHA but also 2-DHA-PC. 相似文献
9.
Concentrates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were heated at 140–240 °C for 2–8 h under nitrogen. The trans isomers were analysed by gas chromatography‐mass spectrometry on a BPX‐70 cyanopropyl column. All geometrical isomers of EPA and DHA with one trans double bond were observed. The rate constants (k) for the isomerisation of the all‐cis isomers were calculated and found to be higher than previously reported for linoleic acid and α‐linolenic acid. Arrhenius plots showed a linear relationship between ln k and the reciprocal absolute temperature above 180 °C. The distribution patterns of isomers with one trans double bond are approximately constant up to a degree of isomerisation of 25%. The degree of isomerisation can therefore be estimated from selected trans peaks. 相似文献
10.
Eicosapentaenoic acid and docosahexaenoic acid production potential of microalgae and their heterotrophic growth 总被引:9,自引:0,他引:9
Twenty microalgal strains were investigated in photoautotrophic flask cultures for their potential for eicosapentaenoic acid
(EPA) and docosahexaenoic acid (DHA) production. The highest EPA proportion (% of total fatty acids) was produced by Monodus subterraneus UTEX 151 (34.2%), followed by Chlorella minutissima UTEX 2341 (31.3%) and Phaeodactylum tricornutum UTEX 642 (21.4%). The highest DHA proportion (% of total fatty acids) was obtained in Crypthecodinium cohnii UTEX L1649 (19.9%), followed by Amphidinium carterae UTEX LB 1002 (17.0%) and Thraustochytrium aureum ATCC 28211 (16.1%). Among the 20 strains screened, the EPA yield was high in M. subterraneus UTEX 151 (96.3 mg/L), P. tricornutum UTEX 642 (43.4 mg/L), Chl. minutissima UTEX 2341 (36.7 mg/L), and Por. cruentum UTEX 161 (17.9 mg/L) owing to their relatively high biomass concentrations. The DHA yield was high in C. cohnii UTEX L1649 (19.5 mg/L) and A. carterae UTEX LB 1002 (8.6 mg/L). Heterotrophic growth of these 20 microalgae was also tested on two different carbon sources, acetate
and glucose. All microalgae except Nannochloropsis oculata UTEX LB 2164 showed growth on glucose (5 g/L) under heterotrophic conditions. Twelve of them could grow heterotrophically
when acetate (1 g/L) was used as their sole carbon and energy source. 相似文献
11.
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13.
Yukihisa Tanaka Jiro Hirano Tadashi Funada 《Journal of the American Oil Chemists' Society》1994,71(3):331-334
Docosahexaenoic acid (DHA) in the free fatty acid (FFA) derived from enzymically hydrolyzed tuna oil was concentrated by partial
titration and precipitation of other FFA as sodium salts with acetone. A triglyceride containing up to 46.2% DHA was synthesized
from the DHA-rich glyceride mixture and FFA by use of an immobilizedChromobacterium viscosum lipase. 相似文献
14.
Ching T. Hou 《Journal of the American Oil Chemists' Society》1994,71(9):975-978
A new microbial isolate,Flavobacterium sp. strain DS5, converts linoleic acid into 10-hydroxy-12(Z)-octadecenoic acid (10-HOA) with 55% yield. The product was characterized
by gas chromatography (GC), GC/mass spectrometry, nuclear magnetic resonance and Fourier transform infrared spectroscopy.
The specific optical rotation of 10-HOA is [α]
D
24
=−5.58 (methanol). The optimum time, pH and temperature for the production of 10-HOA were 36h, 7.5 and 20–35°C, respectively.
The enzyme(s) that converts linoleic acid to 10-HOA is soluble and located intracellulary in strain DS5. Two minor products,
10-methoxy-12-octade-cenoic acid and 10-keto-12-octadecenoic acid, were also identified. 10-HOA was further metabolized by
strain DS5. Among the unsaturated fatty acids studied, the order of reactivity for the DS5 enzyme(s) is oleic>palmitoleic>
linoleic>linolenic>γ-linolenic>myristoleic acid. 相似文献
15.
M. J. Ibáñez González A. Robles Medina E. Molina Grima A. Giménez Giménez M. Carstens L. Esteban Cerdán 《Journal of the American Oil Chemists' Society》1998,75(12):1735-1740
Fatty acids in the microalga Phaeodactylum tricornutum were isolated using an optimized three-step method: extraction of crude fatty acid potassium salts made by direct saponification
of lipids in the microalgal biomass with KOH/ethanol (96%, vol/vol), separation of unsaponifiable lipids by extraction with
hexane, and final purification of fatty acids by acidification of the alcoholic solution of potassium soaps followed by extraction
of fatty acid into hexane. Direct saponification was carried out in ethanol (96%, vol/vol) using 2.09 mL ethanol (96%) per
gram of wet biomass (10 mL/g of dry biomass) mixed with 0.4 g KOH/g of biomass. Under these conditions the fatty acid yield
was 87%. The optimal water content of the alcoholic solution for extraction of the unsapononifiables was established as 40%,
w/w. Data on equilibrium carotenoid distribution between the alcoholic (40%, w/w water) and hexane phases were determined.
These data allow prediction of the carotenoid yields with different volumes of hexane in several extraction steps. The optimal
pH of the alcoholic solution before extracting the purified fatty acid was established as pH 6, and the equilibrium fatty
acid distribution between the alcoholic and hexane phases was determined. This optimized method permited a 20% reduction in
the production costs of highly purified eicosapentaenoic acid (EPA) in the three-step preparative process (extraction of fatty
acid, concentration of polyunsaturated fatty acids by the urea method, and EPA fractionation through preparative high-performance
liquid chromatography) previously developed by the authors. 相似文献
16.
Separation of eicosapentaenoic acid and docosahexaenoic acid in fish oil by kinetic resolution using lipase 总被引:5,自引:0,他引:5
Gudmundur G. Haraldsson Björn Kristinsson 《Journal of the American Oil Chemists' Society》1998,75(11):1551-1556
The objective of this study was to investigate the use of lipases as catalysts for separating eicosapentaenoic acid (EPA)
and docosahexaenoic acid (DHA) in fish oil by kinetic resolution. Transesterification of various fish oil triglycerides with
a stoichiometric amount of ethanol by immobilized Rhizomucor miehei lipase under anhydrous solvent-free conditions resulted in a good separation. When free fatty acids from the various fish
oils were directly esterified with ethanol under similar conditions, greatly improved results were obtained. By this modification,
complications related to regioselectivity of the lipase and nonhomogeneous distribution of EPA and DHA into the various positions
of the triglycerides were avoided. As an example, when tuna oil comprising 6% EPA and 23% DHA was transesterified with ethanol,
65% conversion into ethyl esters was obtained after 24 h. The residual glyceride mixture contained 49% DHA and 6% EPA (8:1),
with 90% DHA recovery into the glyceride mixture and 60% EPA recovery into the ethyl ester product. When the corresponding
tuna oil free fatty acids were directly esterified with ethanol, 68% conversion was obtained after only 8h. The residual free
fatty acids comprised 74% DHA and only 3% EPA (25:1). The recovery of both DHA into the residual free fatty acid fraction
and EPA into the ethyl ester product remained very high, 83 and 87%, respectively. 相似文献
17.
Michelle L. Baack Susan E. Puumala Stephen E. Messier Deborah K. Pritchett William S. Harris 《Lipids》2016,51(4):423-433
Docosahexaenoic acid (DHA) is an essential fatty acid (FA) important for health and neurodevelopment. Premature infants are at risk of DHA deficiency and circulating levels directly correlate with health outcomes. Most supplementation strategies have focused on increasing DHA content in mother's milk or infant formula. However, extremely premature infants may not reach full feedings for weeks and commercially available parenteral lipid emulsions do not contain preformed DHA, so blood levels decline rapidly after birth. Our objective was to develop a DHA supplementation strategy to overcome these barriers. This double‐blind, randomized, controlled trial determined feasibility, tolerability and efficacy of daily enteral DHA supplementation (50 mg/day) in addition to standard nutrition for preterm infants (24–34 weeks gestational age) beginning in the first week of life. Blood FA levels were analyzed at baseline, full feedings and near discharge in DHA (n = 31) or placebo supplemented (n = 29) preterm infants. Term peers (n = 30) were analyzed for comparison. Preterm infants had lower baseline DHA levels (p < 0.0001). Those receiving DHA had a progressive increase in circulating DHA over time (from 3.33 to 4.09 wt% or 2.88 to 3.55 mol%, p < 0.0001) while placebo‐supplemented infants (receiving standard neonatal nutrition) had no increase over time (from 3.35 to 3.32 wt% or 2.91 to 2.87 mol%). Although levels increased with additional DHA supplementation, preterm infants still had lower blood DHA levels than term peers (4.97 wt% or 4.31 mol%) at discharge (p = 0.0002). No differences in adverse events were observed between the groups. Overall, daily enteral DHA supplementation is feasible and alleviates deficiency in premature infants. 相似文献
18.
19.
S. P. J. Namal Senanayake Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》1999,76(9):1009-1015
Lipase-catalyzed acidolysis of acylglycerols of borage (Borago officinalis L.) oil with a docosahexaenoic acid (DHA) concentrate, prepared from algal oil, in organic solvents was studied. Seven lipases
were used as biocatalysts for the acidolysis reaction. Novozyme 435 from Candida antarctica, as compared to lipases from Mucor miehei and Pseudomonas sp., showed the highest degree of DHA incorporation into borage oil. Other lipases tested, such as those from Aspergillus niger, C. rugosa, Thermomyces lanuginousus and Achromobacter lunatus, were rather ineffective in the incorporation of DHA into borage oil. Effects of variation of reaction parameters, namely,
enzyme load, temperature, time course, and type of solvent, were monitored for C. antarctica as the biocatalyst of choice. Incorporation of DHA increased with increasing amount of enzyme, reaching 27.4% at an enzyme
concentration of 150 lipase activity units. As incubation time progressed, DHA incorporation also increased. After a reaction
time of 24 h, the contents of total n-6 and n-3 polyunsaturated fatty acids in acylglycerols were 44.0 and 27.6%, respectively.
The highest degree of DHA incorporation was achieved when hexane was used as the reaction medium. The positional distribution
of DHA in modified borage oil was determined using pancreatic lipase hydrolysis. Results showed that DHA was randomly distributed
over the sn-1, sn-2, and sn-3 positions of the triacylglycerol. Thus, preparation of modified borage oil acylglycerols containing both DHA (22:6n-3;
27.4%) and γ-linolenic acid (18:3n-6; 17.0%) was successfully achieved and products so obtained may have beneficial effects
beyond simple physical mixtures of the two oils. The final oil had a ratio of n-3 to n-6 of 0.42–0.62 which is nutritionally
more suitable than the original unaltered borage oil. 相似文献
20.
E. Rodríguez M. J. Espuny A. Manresa A. Guerrero 《Journal of the American Oil Chemists' Society》2001,78(6):593-597
Pseudomonas sp. 32T3, a newly identified strain originally isolated from a vegetable oil-contaminated soil, produces three monohydroxy acids—(E)-11-hydroxy-9-octadecenoic acid, (E)-10-hydroxy-8-octadecenoic acid, and (E)-9-hydroxy-10-octadecenoic acid—as bioconversion products of oleic acid. The bacterial cells were grown in a mineral medium containing oleic acid as the main carbon substrate. The compounds were identified as the corresponding methyl esters on the basis of their chromatographic and spectroscopic (1H and 13C nuclear magnetic resonance and gas chromatography-mass spectrometry) features. 相似文献