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.
Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist individually, or in chains or groups. Depending on the species, their sizes can range from a few micrometers (μm) to a few hundred micrometers. Unlike higher plants, microalgae do not have roots, stems, or leaves. They are specially adapted to an environment dominated by viscous forces.
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.
Phaeodactylum tricornutum is a diatom. It is the only species in the genus Phaeodactylum. Unlike other diatoms, P. tricornutum can exist in different morphotypes and changes in cell shape can be stimulated by environmental conditions. This feature can be used to explore the molecular basis of cell shape control and morphogenesis. Unlike most diatoms, P. tricornutum can grow in the absence of silicon and can survive without making silicified frustules. This provides opportunities for experimental exploration of silicon-based nanofabrication in diatoms.
Scenedesmus is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile. They are one of the most common components of phytoplankton in freshwater habitats worldwide.
Algae fuel, algal biofuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane. When made from seaweed (macroalgae) it can be known as seaweed fuel or seaweed oil.
Phospholipid-derived fatty acids (PLFAs) are widely used in microbial ecology as chemotaxonomic markers of bacteria and other organisms. Phospholipids are the primary lipids composing cellular membranes. Phospholipids can be saponified, which releases the fatty acids contained in their diglyceride tail. Once the phospholipids of an unknown sample are saponified, the composition of the resulting PLFA can be compared to the PLFA of known organisms to determine the identity of the sample organism. PLFA analysis may be combined with other techniques, such as stable isotope probing to determine which microbes are metabolically active in a sample. PLFA analysis was pioneered by D.C. White at the University of Tennessee, in the early to mid 1980s.
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.
Shewanella violacea DSS12 is a gram-negative bacterium located in marine sediment in the Ryukyu Trench at a depth of 5,110m. The first description of this organism was published in 1998 by Japanese microbiologists Yuichi Nogi, Chiaki Kato, and Koki Horikoshi, who named the species after its violet appearance when it is grown on Marine Agar 2216 Plates.
Schizochytrium is a genus of unicellular eukaryotes in the family Thraustochytriaceae, which are found in coastal marine habitats. They are assigned to the Stramenopiles (heterokonts), a group which also contains kelp and various microalgae.
Epoxide docosapentaenoic acids are metabolites of the 22-carbon straight-chain omega-3 fatty acid, docosahexaenoic acid (DHA). Cell types that express certain cytochrome P450 (CYP) epoxygenases metabolize polyunsaturated fatty acids (PUFAs) by converting one of their double bonds to an epoxide. In the best known of these metabolic pathways, cellular CYP epoxygenases metabolize the 20-carbon straight-chain omega-6 fatty acid, arachidonic acid, to epoxyeicosatrienoic acids (EETs); another CYP epoxygenase pathway metabolizes the 20-carbon omega-3 fatty acid, eicosapentaenoic acid (EPA), to epoxyeicosatetraenoic acids (EEQs). CYP epoxygenases similarly convert various other PUFAs to epoxides. These epoxide metabolites have a variety of activities. However, essentially all of them are rapidly converted to their corresponding, but in general far less active, vicinal dihydroxy fatty acids by ubiquitous cellular soluble epoxide hydrolase. Consequently, these epoxides, including EDPs, operate as short-lived signaling agents that regulate the function of their parent or nearby cells. The particular feature of EDPs distinguishing them from EETs is that they derive from omega-3 fatty acids and are suggested to be responsible for some of the beneficial effects attributed to omega-3 fatty acids and omega-3-rich foods such as fish oil.
Chlorella vulgaris is a species of green microalga in the division Chlorophyta. It is mainly used as a dietary supplement or protein-rich food additive in Japan.
Thalassiosira is a genus of centric diatoms, comprising over 100 marine and freshwater species. It is a diverse group of photosynthetic eukaryotes that make up a vital part of marine and freshwater ecosystems, in which they are key primary producers and essential for carbon cycling
Isotope effect is observed when molecules containing heavier isotopes of the same atoms are engaged in a chemical reaction at a slower rate. Deuterium-reinforced lipids can be used for the protection of living cells by slowing the chain reaction of lipid peroxidation. The lipid bilayer of the cell and organelle membranes contain polyunsaturated fatty acids (PUFA) are key components of cell and organelle membranes. Any process that either increases oxidation of PUFAs or hinders their ability to be replaced can lead to serious disease. Correspondingly, drugs that stop the chain reaction of lipid peroxidation have preventive and therapeutic potential.
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.
Skeletonema costatum is a cosmopolitan centric diatom that belongs to the genus Skeletonema. It was first described by R. K. Greville, who originally named it Melosira costata, in 1866. It was later renamed by Cleve in 1873 and was more narrowly defined by Zingone et al. and Sarno et al. Skeletonemacostatum is the most well known species of the genus Skeletonema and is often one of the dominant species responsible for red tide events.
Tisochrysis lutea is a species of Haptophyta formerly known as Isochrysis affinis galbana (Tahiti isolate) or 'T-iso'.
