Lipids, trophic relationships, and biodiversity in Arctic and Antarctic krill

2000 ◽  
Vol 57 (S3) ◽  
pp. 178-191 ◽  
Author(s):  
Stig Falk-Petersen ◽  
Wilhelm Hagen ◽  
Gerhard Kattner ◽  
Andrew Clarke ◽  
John Sargent
Keyword(s):  
Fatty Acids ◽  
Neutral Lipids ◽  
Critical Factor ◽  
Euphausia Superba ◽  
High Ratio ◽  
Wax Esters ◽  
Trophic Relationships ◽  
The Arctic ◽  
Lower Ratio ◽  
The Antarctic

Environmental seasonality is a critical factor in structuring polar marine ecosystems. The extensive data now available on the lipids of Arctic and Antarctic euphausiids show that all species are characterised by a seasonally high lipid content, and neutral lipids, whether wax esters or triacylglycerols, are primarily accumulated for reproduction. The Arctic Thysanoessa inermis and the Antarctic Euphausia crystallorophias contain high levels of wax esters and higher concentrations of 18:4(n-3) and 20:5(n-3) and a lower ratio of 18:1(n-9)/(n-7) fatty acids in their neutral lipids than the Arctic Thysanoessa raschii and the Antarctic Thysanoessa macrura and Euphausia superba. Large amounts of phytol in the lipids of T. raschii and E. crystallorophias during winter suggest the ingestion of decaying algae originating in sedimenting material or in sea ice. Thysanoessa raschii, T. macrura, and E. superba have a high ratio of 18:1(n-9)/ (n-7) fatty acids, indicating animal carnivory. We conclude that T. inermis and E. crystallorophias are true high polar herbivores, while T. raschii, T. macrura, and E. superba are omnivores with a more boreal distribution. The Arctic species Thysanoessa longicaudata and Meganyctiphanes norvegica are carnivores feeding on Calanus, as indicated by high amounts of 20:1(n-9) and 22:1(n-11) fatty acids.

Wax esters versus triacylglycerols in myctophid fishes from the Southern Ocean

1999 ◽  
Vol 11 (4) ◽  
pp. 436-444 ◽  
Author(s):  
Charles F. Phleger ◽  
Matthew M. Nelson ◽  
Ben D. Mooney ◽  
Peter D. Nichols
Keyword(s):  
Fatty Acids ◽  
Saturated Fatty Acids ◽  
Dry Weight ◽  
Euphausia Superba ◽  
Wax Esters ◽  
Fatty Acid Profiles ◽  
Island Region ◽  
Vertebral Centra ◽  
A Minor ◽  
The Antarctic

Five species of myctophid fishes were collected by trawl from the Elephant Island region of the Antarctic Peninsula between 60°30′–62°S and 55°–61°30′W. Two species, Gymnoscopelus braueri and Krefftichthyes anderssoni were lipid-rich (406–456 mg g−1 dry weight whole fish) with wax esters (WE) the major lipid class. In three species, G. opisthopterus, G. nicholsi, and Electrona carlsbergii, triacylglycerols (TAG) were the major lipid. All fish had oily bones, with values up to 471 mg g−1 dry weight in the vertebral centra of K. anderssoni. The principal fatty acids of the TAG-rich myctophids included the monoenes 18:1(n-9) and 20:1. There were lower levels of 16:0 and 18:0 saturated fatty acids. Polyunsaturated fatty acids (PUFA) were present at higher abundance in the TAG-rich E. carlsbergii and G. opisthopterus, with lower levels in G. nicholsi. In comparison, the WE-dominated species contained lower levels of PUFA than in the TAG-rich species. The principal fatty acids of the WE-rich myctophids included the monoenes 18:1(n-9), 16:1(n-7), and 18:1(n-7), with lower levels of the saturated acids 16:0 and 18:0. Fatty alcohols were dominated by 16:0 and 14:0 and the monounsaturated 18:1(n-9) with 16:1(n-7), 18:1(n-7), and 20:1(n-9). Based on the fatty acid profiles, the diet of G. opishtopterus and G. nicholsi, previously thought to be mainly Euphausia superba, is suggested to include copepods and other zooplankton with only a minor krill component, possibly consisting of other species than E. superba.

scholarly journals Metabolic and enzymatic adaptations in northern krill,Meganyctiphanes norvegica, and Antarctic krill,Euphausia superba

2000 ◽  
Vol 57 (S3) ◽  
pp. 115-129 ◽  
Author(s):  
Friedrich Buchholz ◽  
Reinhard Saborowski
Keyword(s):  
Antarctic Krill ◽  
Citrate Synthase ◽  
Enzyme Regulation ◽  
Euphausia Superba ◽  
Food Sources ◽  
The Arctic ◽  
Ligurian Sea ◽  
Meganyctiphanes Norvegica ◽  
The Antarctic ◽  
Antarctic Krill Euphausia Superba

The Antarctic krill, Euphausia superba, is restricted to the Antarctic Ocean. The northern krill, Meganyctiphanes norvegica, is extremely widely distributed from the arctic North Atlantic to the warm Mediterranean. Respiration measurements showed no seasonal differences in rates determined in krill from the thermally stable Clyde Sea (Scotland) and the cooler but variable Danish Kattegat. In the warm Ligurian Sea, where temperatures are stable, krill showed higher rates in April than in September, indicating reactions to the short but intensive productive season. Krill can passively benefit from enhancements of overall metabolism when ascending into upper, warmer water strata during their pronounced diel vertical migration. Michaelis-Menten constants (Km) of citrate synthase (CS) were compared. In terms of respiration and enzyme regulation, krill from the Ligurian Sea stand apart: temperature and nutrition appear to be of different influence, relatable to genetic differentiation in the species. In contrast, Kmof CS in E. superba is temperature independent, highlighting the species' stenothermal physiology. A basal level of activity of digestive enzymes ensures immediate utilization of patchy food sources. Specific induction, including that of chitinases, indicating omnivory in both species, underlines krill's exceptional capacity to adapt to highly variable trophic environments. Processes of moult, growth, and reproduction are locally and seasonally adjusted.

Seals and whales of the Southern Ocean

1977 ◽  
Vol 279 (963) ◽  
pp. 81-96 ◽  
Keyword(s):  
Southern Ocean ◽  
Marine Mammals ◽  
Deep Ocean ◽  
Euphausia Superba ◽  
The Body ◽  
The Arctic ◽  
Individual Species ◽  
Baleen Whales ◽  
Fur Seals ◽  
The Antarctic

There are fewer species of marine mammals in the Antarctic than in the Arctic, probably because of the wide deep ocean with no geographical barriers to promote speciation. The stocks are substantially larger in the Antarctic and the body sizes of individual species are larger, probably owing to a more abundant food supply. Seasonal changes in the environment in the Southern Ocean are marked and food available to baleen whales is very much greater in summer. Ecological interactions of the consumers, principally in relation to krill Euphausia superba , are discussed and attention drawn to some of the ways in which ecological separation is achieved, both within and between species. Estimates of abundances, biomasses and food requirements are given for the seals and large whales. The original numbers of whales in the Antarctic were far greater than in other oceans, but the stocks have been severely reduced by whaling. This may have increased the availability of krill to other consumers by as much as 150 million tonnes annually. Increased growth rates, earlier maturity and higher pregnancy rates have been demonstrated for baleen whale species, and earlier maturity for the crabeater seal. While it has not been possible to demonstrate increases in the populations of any of these species, the stocks of fur seals and penguins have been monitored and show significant population increases. A key question is whether the original balance of this ecosystem can be regained with appropriate management.

scholarly journals Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

2006 ◽  
Vol 72 (2) ◽  
pp. 1373-1379 ◽  
Author(s):  
Rainer Kalscheuer ◽  
Tim Stöveken ◽  
Heinrich Luftmann ◽  
Ursula Malkus ◽  
Rudolf Reichelt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Neutral Lipids ◽  
Wax Esters ◽  
Wax Ester ◽  
Jojoba Oil ◽  
E Coli ◽  
Butyl Esters ◽  
Long Chain

ABSTRACT Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

The Distribution of Neutral Lipids in Shark Tissues

1973 ◽  
Vol 53 (3) ◽  
pp. 649-656 ◽  
Author(s):  
J. R. Sargent ◽  
R. R. Gatten ◽  
R. McIntosh
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Polyunsaturated Fatty Acids ◽  
Neutral Lipid ◽  
Lipid Class ◽  
Deep Sea ◽  
Neutral Lipids ◽  
Wax Esters ◽  
Cholesteryl Esters ◽  
A Minor

Neutral lipid classes were analysed in the livers, muscles and sera of Deania, Centroscymnus, Squalus and Prionace. All three squaloid sharks contained triglycerides and alkyldiacylglycerols and the two deep sea squaloids contained additionally hydrocarbons. Prionace contained triglycerides and hydrocarbons but no alkyldiacylglycerols. For a given species the class compositions of the lipids were similar in liver, muscle and serum, except that serum contained additionally cholesteryl esters and wax esters. Cholesteryl esters in Squalus serum were rich in oleic acid whereas wax esters were very rich in polyunsaturated fatty acids. Squalus serum contained a major and a minor lipoprotein species both of which transport all four neutral lipids in serum. It is concluded that, with the exception of cholesteryl and wax esters in serum, neutral lipids are distributed between shark tissues by a mechanism that is relatively non-specific with respect to lipid class.

scholarly journals Advances in Technologies for Highly Active Omega-3 Fatty Acids from Krill Oil: Clinical Applications

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 306
Author(s):  
Alessandro Colletti ◽  
Giancarlo Cravotto ◽  
Valentina Citi ◽  
Alma Martelli ◽  
Lara Testai ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Marine Ecosystem ◽  
Euphausia Superba ◽  
Krill Oil ◽  
Omega 3 ◽  
Highly Active ◽  
Marine Crustacean ◽  
Lipid Compounds ◽  
The Antarctic ◽  
Preventive Effects

Euphausia superba, commonly known as krill, is a small marine crustacean from the Antarctic Ocean that plays an important role in the marine ecosystem, serving as feed for most fish. It is a known source of highly bioavailable omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In preclinical studies, krill oil showed metabolic, anti-inflammatory, neuroprotective and chemo preventive effects, while in clinical trials it showed significant metabolic, vascular and ergogenic actions. Solvent extraction is the most conventional method to obtain krill oil. However, different solvents must be used to extract all lipids from krill because of the diversity of the polarities of the lipid compounds in the biomass. This review aims to provide an overview of the chemical composition, bioavailability and bioaccessibility of krill oil, as well as the mechanisms of action, classic and non-conventional extraction techniques, health benefits and current applications of this marine crustacean.

Lipids of Zooplankton from Bute Inlet, British Columbia

1974 ◽  
Vol 31 (10) ◽  
pp. 1577-1582 ◽  
Author(s):  
Richard F. Lee
Keyword(s):  
Fatty Acids ◽  
British Columbia ◽  
Organic Matter ◽  
Lipid Analysis ◽  
Neutral Lipids ◽  
Phospholipid Fatty Acid ◽  
Total Phospholipid ◽  
Wax Esters ◽  
Storage Lipid ◽  
Pleurobrachia Pileus

Seventeen species of zooplankton representing four phyla were collected from Bute Inlet, one of the deep inlets (650 m) in British Columbia. Using lipid analysis and starvation studies, the zooplankton were divided into two categories based on whether the level of storage lipid was high or low. The polychaetaes, chaetognaths, and one of the ctenophores (Pleurobrachia pileus) were characterized by little storage lipid (neutral lipid only 7–10% of the lipid). It is assumed that these species transfer most new organic matter into new tissue rather than storage lipid. The copepods, Calanus plumchrus, Eucalanus bungi, Gaetanus columbiae, and Heterorhadus tanneri, were all characterized by high levels of storage lipid (between 53 and 90% of the lipid) and, except for Eucalanus, these consisted mainly of wax esters. The remaining zooplankters (ostracods, pteropods, euphausiids, amphipods, and decapods), except for the ctenophore, Beroe cucumis, stored primarily triglycerides. In all species examined, except B. cucumis, five fatty acids, 16:0, 16:1, 18:1, 20:5, and 22:6, accounted for over 90% of the total phospholipid fatty acid complement. Polyunsaturated C16 and C18 acids, which are common in phytoplankton, were absent or present in trace amounts in phospholipids but were abundant in the neutral lipids of herbivorous zooplankton. The wax esters of G. columbiae and B. cucumis had high levels of 16:0, 20:1, and 22:1 alcohols, whereas C. plumchrus had only 20:1 and 22:1 alcohols as major components.

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