Omega−3 fatty acids, also called Omega−3 oils, ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chemical structure. They are widely distributed in nature, being important constituents of animal lipid metabolism, and they play an important role in the human diet and in human physiology. The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA can be found in plants, while DHA and EPA are found in algae and fish. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. DHA and EPA accumulate in fish that eat these algae. Common sources of plant oils containing ALA include walnuts, edible seeds, and flaxseeds as well as hempseed oil, while sources of EPA and DHA include fish and fish oils, and algae oil.
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health, but cannot synthesize them.
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body and improve hypertriglyceridemia. There has been a great deal of controversy in the 21st century about the role of fish oil in cardiovascular disease, with recent meta-analyses reaching different conclusions about its potential impact.
Eicosapentaenoic acid is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. It is given the fatty acid notation 22:6(n-3). It can be synthesized from alpha-linolenic acid or obtained directly from maternal milk, fatty fish, fish oil, or algae oil. The consumption of DHA contributes to numerous physiological benefits, including cognition. As the primary structural component of nerve cells in the brain, the function of DHA is to support neuronal conduction and to allow optimal function of neuronal membrane proteins.
Docosapentaenoic acid (DPA) designates any straight open chain polyunsaturated fatty acid (PUFA) which contains 22 carbons and 5 double bonds. DPA is primarily used to designate two isomers, all-cis-4,7,10,13,16-docosapentaenoic acid and all-cis-7,10,13,16,19-docosapentaenoic acid. They are also commonly termed n-6 DPA and n-3 DPA, respectively; these designations describe the position of the double bond being 6 or 3 carbons closest to the (omega) carbon at the methyl end of the molecule and is based on the biologically important difference that n-6 and n-3 PUFA are separate PUFA classes, i.e. the omega-6 fatty acids and omega-3 fatty acids, respectively. Mammals, including humans, can not interconvert these two classes and therefore must obtain dietary essential PUFA fatty acids from both classes in order to maintain normal health.
Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the FASN gene.
Linoleoyl-CoA desaturase (also Delta 6 desaturase, EC 1.14.19.3) is an enzyme that converts between types of fatty acids, which are essential nutrients in the human body. The enzyme mainly catalyzes the chemical reaction
In enzymology, an erythronolide synthase is an enzyme that catalyzes the chemical reaction
Bigyra is a phylum of microscopic eukaryotes that are found at the base of the Stramenopiles clade. It includes three well-known heterotrophic groups Bicosoecida, Opalinata and Labyrinthulomycetes, as well as several small clades initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea. The classification of Bigyra has changed several times since its origin, and its monophyly remains unresolved.
Diacronema is a genus of haptophytes.
Nannochloropsis is a genus of algae comprising six known species. The genus in the current taxonomic classification was first termed by Hibberd (1981). The species have mostly been known from the marine environment but also occur in fresh and brackish water. All of the species are small, nonmotile spheres which do not express any distinct morphological features that can be distinguished by either light or electron microscopy. The characterisation is mostly done by rbcL gene and 18S rRNA sequence analysis.
Manufactured feeds are an important part of modern commercial aquaculture, providing the balanced nutrition needed by farmed fish. The feeds, in the form of granules or pellets, provide the nutrition in a stable and concentrated form, enabling the fish to feed efficiently and grow to their full potential.
Crypthecodinium cohnii is a species of dinoflagellate microalgae. It is used industrially in the production of docosahexaenoic acid. Crypthecodinium cohnii is a heterotrophic non-photosynthetic Microalgae. C. cohnii can acclimate a higher docosahexaenoic acid to polyunsaturated fatty acids ratio, however current studies are trying to increase the volume of DHA production by creating mutant strains. Studies have shown that an increase in the supply of Dissolved Oxygen results in an increased production of DHA. In addition to oxygen concentration, C. cohnii is known to react to a change in salinity by changing their growth rate. C. cohnii's growth is highly dependent on their microbiome or environment. Most of the DHA in the Microalgae is found in the phospholipid, phosphatidylcholine. C. cohnii cultures require an organic carbon source to allow for accumulation of DHA. C. cohnii has been shown to accumulate other fatty acids and starch, especially due to nutrient limitation. C. cohnii showed the greatest accumulation of lipids when grown in a pH auxostat culture.
Schizochytrium limacinum is a species of thraustochytrids first isolated from a mangrove area in the western Pacific Ocean. It differs from other Schizochytrium species in its limaciform amoeboid cells, the size of its zoospores, and its assimilation profile of carbon sources.
Ketoacyl synthases (KSs) catalyze the condensation reaction of acyl-CoA or acyl-acyl ACP with malonyl-CoA to form 3-ketoacyl-CoA or with malonyl-ACP to form 3-ketoacyl-ACP. This reaction is a key step in the fatty acid synthesis cycle, as the resulting acyl chain is two carbon atoms longer than before. KSs exist as individual enzymes, as they do in type II fatty acid synthesis and type II polyketide synthesis, or as domains in large multidomain enzymes, such as type I fatty acid synthases (FASs) and polyketide synthases (PKSs). KSs are divided into five families: KS1, KS2, KS3, KS4, and KS5.
Seaweed oil, also called algae oil or algal oil, is used for making food, with the purified product almost colorless and odorless. It is also under development as a possible alternative fuel and manufacturing agent.
Thraustochytrids are single-celled saprotrophic eukaryotes (decomposers) that are widely distributed in marine ecosystems, and which secrete enzymes including, but not limited to amylases, proteases, phosphatases. They are most abundant in regions with high amounts of detritus and decaying plant material. They play an important ecological role in mangroves, where they aid in nutrient cycling by decomposing decaying matter. Additionally, they contribute significantly to the synthesis of omega-3 polyunsaturated fatty acids (PUFAs): docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), which are essential fatty acids for the growth and reproduction of crustaceans. Thraustochytrids are members of the class Labyrinthulea, a group of protists that had previously been incorrectly categorized as fungi due to their similar appearance and lifestyle. With the advent of DNA sequencing technology, labyrinthulomycetes were appropriately placed with other stramenopiles and subsequently categorized as a group of Labyrinthulomycetes.
Tisochrysis lutea is a species of Haptophyta formerly known as Isochrysis affinis galbana (Tahiti isolate) or 'T-iso'.
