Basidiomycota is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya within the kingdom Fungi. Basidiomycota are filamentous fungi composed of hyphae and reproduce sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores and these specialized spores are called basidiospores. However, some Basidiomycota reproduce asexually in addition or exclusively, the most recent classification adopted by a coalition of 67 mycologists recognizes three subphyla and two other class level taxa outside of these, among the Basidiomycota. As now classified, the join and cut across various obsolete taxonomic groups previously commonly used to describe Basidiomycota. According to a 2008 estimate, Basidiomycota comprise three subphyla 16 classes,52 orders,177 families,1,589 genera, and 31,515 species, the terms basidiomycetes and ascomycetes are frequently used loosely to refer to Basidiomycota and Ascomycota.
They are often abbreviated to basidios and ascos as mycological slang, the Agaricomycotina include what had previously been called the Hymenomycetes, the Gasteromycetes, as well as most of the jelly fungi. The three classes in the Agaricomycotina are the Agaricomycetes, the Dacrymycetes, and the Tremellomycetes, the class Wallemiomycetes is not yet placed in a subdivision, but recent genomic evidence suggests that it is a sister group of Agaricomycotina. The Ustilaginomycotina are most of the former smut fungi and the Exobasidiales, the classes of the Ustilaginomycotina are the Exobasidiomycetes, the Entorrhizomycetes, and the Ustilaginomycetes. Typically haploid Basidiomycota mycelia fuse via plasmogamy and the compatible nuclei migrate into each others mycelia, karyogamy is delayed, so that the compatible nuclei remain in pairs, called a dikaryon. The hyphae are said to be dikaryotic. Conversely, the mycelia are called monokaryons. Often, the mycelium is more vigorous than the individual monokaryotic mycelia.
The dikaryons can be long-lived, lasting years, decades, or centuries, the monokaryons are neither male nor female. They have either a bipolar or a mating system. However, there are variations of these genes in the population. It is as if there were multiple sexes, meiosis follows shortly with the production of 4 haploid nuclei that migrate into 4 external, usually apical basidiospores. Typically the basidiospores are ballistic, hence they are called ballistospores. In most species, the basidiospores disperse and each can start a new haploid mycelium, basidia are microscopic but they are often produced on or in multicelled large fructifications called basidiocarps or basidiomes, or fruitbodies), variously called mushrooms, etc
Anthoxanthins are a type of flavonoid pigments in plants. Anthoxanthins are water-soluble pigments which range in color from white or colorless to a creamy to yellow and these pigments are generally whiter in an acid medium and yellowed in an alkaline medium. They are very susceptible to changes with minerals and metal ions. As with all flavonoids, they exhibit antioxidant properties, and are important in nutrition, darkening with iron is particularly prominent in food products. They are considered to have more variety than anthocyanins
Indole is an aromatic heterocyclic organic compound with formula C8H7N. It has a structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is widely distributed in the environment and can be produced by a variety of bacteria. As an intercellular signal molecule, indole regulates various aspects of physiology, including spore formation, plasmid stability, resistance to drugs, biofilm formation. The amino acid tryptophan is a derivative and the precursor of the neurotransmitter serotonin. Indole is a solid at room temperature, Indole can be produced by bacteria as a degradation product of the amino acid tryptophan. It occurs naturally in feces and has an intense fecal odor. At very low concentrations, however, it has a flowery smell and it occurs in coal tar. The corresponding substituent is called indolyl, Indole undergoes electrophilic substitution, mainly at position 3. Substituted indoles are structural elements of the tryptophan-derived tryptamine alkaloids like the neurotransmitter serotonin, other indolic compounds include the plant hormone auxin, the anti-inflammatory drug indomethacin, the betablocker pindolol, and the naturally occurring hallucinogen dimethyltryptamine.
The name indole is a portmanteau of the indigo and oleum. Indole chemistry began to develop with the study of the dye indigo, indigo can be converted to isatin and to oxindole. Then, in 1866, Adolf von Baeyer reduced oxindole to indole using zinc dust, in 1869, he proposed a formula for indole. Certain indole derivatives were important dyestuffs until the end of the 19th century, in the 1930s, interest in indole intensified when it became known that the indole substituent is present in many important alkaloids, and it remains an active area of research today. It condenses with serine by Michael addition of indole to PLP-aminoacrylate, as an intercellular signal molecule, indole regulates various aspects of bacterial physiology, including spore formation, plasmid stability, resistance to drugs, biofilm formation, and virulence. The amino acid tryptophan is a derivative and the precursor of the neurotransmitter serotonin. Indole is a constituent of coal tar, and the 220–260 °C distillation fraction is the main industrial source of the material.
Indole and its derivatives can be synthesized by a variety of methods, the main industrial routes start from aniline via vapor-phase reaction with ethylene glycol in the presence of catalysts, In general, reactions are conducted between 200 and 500 °C
Bougainvillea is a genus of thorny ornamental vines and trees with flower-like spring leaves near its flowers. Different authors accept between four and 18 species in the genus and they are native plants of West Africa Gambia, South America from Brazil west to Peru and south to southern Argentina. Bougainvillea are known as buganvilla, pokok bunga kertas, Napoleón, veranera, the vine species grow anywhere from 1 to 12 m tall, scrambling over other plants with their spiky thorns. The thorns are tipped with a black, waxy substance and they are evergreen where rainfall occurs all year, or deciduous if there is a dry season. The leaves are alternate, simple ovate-acuminate, 4–13 cm long, Bougainvillea glabra is sometimes referred to as paper flower because the bracts are thin and papery. The fruit is a narrow five-lobed achene, Bougainvillea are relatively pest-free plants, but they may suffer from worms and aphids. The larvae of some Lepidoptera species use them as food plants and it is possible that the first European to observe these plants was Jeanne Baré, Commerçons lover and assistant who was an expert in botany.
Because she was not allowed on ship as a woman, she disguised herself as a man in order to make the journey, twenty years after Commerçons discovery, it was first published as Buginvillæa in Genera Plantarum by A. L. de Jussieu in 1789. The genus was subsequently spelled in several ways until it was corrected to Bougainvillea in the Index Kewensis in the 1930s. Originally, B. spectabilis and B. glabra were hardly differentiated until the mid-1980s when botanists recognized them to be distinct species. Meanwhile, Kew Gardens distributed plants it had propagated to British colonies throughout the world, soon thereafter, an important event in the history of bougainvillea took place with the discovery of a crimson specimen in Cartagena, Colombia, by Mrs. R. V. Originally thought to be a species, it was named B. buttiana in her honour. However, it was discovered to be a natural hybrid of a variety of B. glabra. Natural hybrids were found to be common occurrences all over the world. Bougainvillea are popular plants in most areas with warm climates.
Locarno in Switzerland, with its mild Mediterranean climate, is famous for its bougainvillea, although it is frost-sensitive and hardy in USDA Hardiness Zones 9b and 10, bougainvillea can be used as a houseplant or hanging basket in cooler climates. In the landscape, it makes an excellent hot season plant and its high salt tolerance makes it a natural choice for color in coastal regions. It can be pruned into a standard, but is grown along fence lines, on walls, in containers and hanging baskets
Tyrosine or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is an amino acid with a polar side group. Its codons are UAC and UAU, the word tyrosine is from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a group or side chain. Aside from being an amino acid, tyrosine has a special role by virtue of the phenol functionality. It occurs in proteins that are part of signal transduction processes and it functions as a receiver of phosphate groups that are transferred by way of protein kinases. Phosphorylation of the group changes the activity of the target protein. A tyrosine residue plays a important role in photosynthesis. In chloroplasts, it acts as a donor in the reduction of oxidized chlorophyll. In this process, it loses the hydrogen atom of its phenolic OH-group and this radical is subsequently reduced in the photosystem II by the four core manganese clusters.
The Recommended Dietary Allowance for phenylalanine and tyrosine is 33 mg per kilogram of body weight, for a 70 kg person this is 2310 mg. For example, the white of an egg has about 250 mg per egg, in plants and most microorganisms, tyr is produced via prephenate, an intermediate on the shikimate pathway. Mammals synthesize tyrosine from the amino acid phenylalanine, which is derived from food. The conversion of phe to tyr is catalyzed by the enzyme phenylalanine hydroxylase and this enzyme catalyzes the reaction causing the addition of a hydroxyl group to the end of the 6-carbon aromatic ring of phenylalanine, such that it becomes tyrosine. Some of the residues can be tagged with a phosphate group by protein kinases. In its phosphorylated form, tyrosine is called phosphotyrosine, tyrosine phosphorylation is considered to be one of the key steps in signal transduction and regulation of enzymatic activity. Phosphotyrosine can be detected through specific antibodies, tyrosine residues may be modified by the addition of a sulfate group, a process known as tyrosine sulfation.
Tyrosine sulfation is catalyzed by tyrosylprotein sulfotransferase, like the phosphotyrosine antibodies mentioned above, antibodies have recently been described that specifically detect sulfotyrosine
The beetroot is the taproot portion of the beet plant, usually known in North America as the beet, table beet, garden beet, red beet, or golden beet. It is one of several of the varieties of Beta vulgaris grown for their edible taproots. These varieties have been classified as B. vulgaris subsp, other than as a food, beets have use as a food colouring and as a medicinal plant. Many beet products are made from other Beta vulgaris varieties, particularly sugar beet, usually the deep purple roots of beetroot are eaten boiled, roasted or raw, and either alone or combined with any salad vegetable. A large proportion of the production is processed into boiled and sterilized beets or into pickles. In Eastern Europe, beet soup, such as borscht, is a popular dish, in Indian cuisine, cooked, spiced beet is a common side dish. Yellow-coloured beetroots are grown on a small scale for home consumption. The green, leafy portion of the beet is edible, the young leaves can be added raw to salads, whilst the adult leaves are most commonly served boiled or steamed, in which case they have a taste and texture similar to spinach.
Those greens selected should be from bulbs that are unmarked, instead of those with overly limp leaves or wrinkled skins, the domestication of beets can be traced to the emergence of an allele which enables biennial harvesting of leaves and taproot. Pickled beets are a food in many countries. A traditional Pennsylvania Dutch dish is pickled beet egg, hard-boiled eggs are refrigerated in the liquid left over from pickling beets and allowed to marinate until the eggs turn a deep pink-red colour. The same in Serbia where the popular cvekla is used as salad, seasoned with salt and vinegar. As an addition to horseradish it is used to produce the red variety of chrain. Popular in Australian hamburgers, a slice of pickled beetroot is combined with other condiments on a beef patty to make an Aussie burger, when beet juice is used, it is most stable in foods with a low water content, such as frozen novelties and fruit fillings. Beetroot can be used to make wine, food shortages in Europe following World War I caused great hardships, including cases of mangelwurzel disease, as relief workers called it.
It was symptomatic of eating only beets, the chemical adipic acid rarely occurs in nature, but happens to occur naturally in beetroot. From the Middle Ages, beetroot was used as a treatment for a variety of conditions, especially relating to digestion. Bartolomeo Platina recommended taking beetroot with garlic to nullify the effects of garlic-breath, during the middle of the 19th century wine often was coloured with beetroot juice
An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a reaction that can produce free radicals, leading to chain reactions that may damage cells. Antioxidants such as thiols or ascorbic acid terminate these chain reactions, supplementation with selenium or vitamin E does not reduce the risk of cardiovascular disease. Oxidative stress can be considered as either a cause or consequence of some diseases, industrial antioxidants have diverse uses, such as food and cosmetics preservatives and inhibitors of rubber or gasoline deterioration. Although certain levels of antioxidant vitamins in the diet are required for good health, moreover, if they are actually beneficial, it is unknown which antioxidant are needed from the diet and in what amounts beyond typical dietary intake. Some authors dispute the hypothesis that antioxidant vitamins could prevent chronic diseases, which often have antioxidant properties in vitro, are not necessarily antioxidants in vivo due to extensive metabolism.
In many polyphenols, the group acts as electron acceptor and is therefore responsible for the antioxidant activity. However, this catechol group undergoes extensive metabolism upon uptake in the body, for example by catechol-O-methyl transferase. Many polyphenols may have non-antioxidant roles in minute concentrations that affect cell-to-cell signaling, receptor sensitivity, tirilazad is an antioxidant steroid derivative that inhibits the lipid peroxidation that is believed to play a key role in neuronal death in stroke and head injury. It demonstrated activity in animal models of stroke, but human trials demonstrated no effect on mortality or other outcomes in subarachnoid haemorrhage, the designed antioxidant NXY-059 exhibited efficacy in animal models, but failed to improve stroke outcomes in a clinical trial. As of November 2014, other antioxidants are being studied as potential neuroprotectants, common pharmaceuticals with antioxidant properties may interfere with the efficacy of certain anticancer medication and radiation.
During exercise, oxygen consumption can increase by a factor of more than 10, however, no benefits for physical performance to athletes are seen with vitamin E supplementation and 6 weeks of vitamin E supplementation had no effect on muscle damage in ultramarathon runners. Some research suggests that supplementation with amounts as high as 1000 mg of vitamin C inhibits recovery, other studies indicated that antioxidant supplementation may attenuate the cardiovascular benefits of exercise. Relatively strong reducing acids can have antinutrient effects by binding to dietary minerals such as iron and zinc in the gastrointestinal tract, notable examples are oxalic acid and phytic acid, which are high in plant-based diets. Calcium and iron deficiencies are not uncommon in diets in developing countries where meat is eaten and there is high consumption of phytic acid from beans. Nonpolar antioxidants such as major component of oil of cloves—have toxicity limits that can be exceeded with the misuse of undiluted essential oils.
Toxicity associated with high doses of water-soluble antioxidants such as ascorbic acid are less of a concern, more seriously, very high doses of some antioxidants may have harmful long-term effects. The beta-carotene and Retinol Efficacy Trial study of cancer patients found that smokers given supplements containing beta-carotene
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH. They belong to a parent class of molecules called flavonoids synthesized via the pathway, they are odorless but flavorful. Anthocyanins occur in all tissues of plants, including leaves, roots, flowers. Anthoxanthins are clear, white to yellow counterparts of anthocyanins occurring in plants, anthocyanins are derived from anthocyanidins by adding sugars. Anthocyanins have an antioxidant role in plants against reactive oxygen species caused by abiotic stresses, such as overexposure to ultraviolet light, tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell death in leaves. Anthocyanins are considered secondary metabolites as an additive with E number E163, they are approved for use as a food additive in the EU, Australia. Although anthocyanins have antioxidant properties in vitro, this antioxidant effect is not conserved after the plant is consumed, as interpreted by the Linus Pauling Institute and European Food Safety Authority, dietary anthocyanins and other flavonoids have little or no direct antioxidant food value following digestion.
The absorbance pattern responsible for the red color of anthocyanins may be complementary to that of green chlorophyll in photosynthetically active tissues such as young Quercus coccifera leaves and it may protect the leaves from attacks by plant eaters that may be attracted by green color. Anthocyanins are found in the vacuole, mostly in flowers and fruits but in leaves, stems. In these parts, they are predominantly in outer cell layers such as the epidermis. Most frequently occurring in nature are the glycosides of cyanidin, malvidin, peonidin, roughly 2% of all hydrocarbons fixed in photosynthesis are converted into flavonoids and their derivatives such as the anthocyanins. Not all land plants contain anthocyanin, in the Caryophyllales, they are replaced by betalains and betalains have never been found in the same plant. Sometimes bred purposely for high anthocyanin quantities, ornamental plants such as sweet peppers may have unusual culinary, anthocyanins occur in the flowers of many plants, such as the famously blue poppies of some Meconopsis species and cultivars.
Red-fleshed peaches and apples contain anthocyanins, anthocyanins are less abundant in banana, pea, fennel and potato, and may be totally absent in certain cultivars of green gooseberries. The highest recorded amount appears to be specifically in the coat of black soybean containing around 2 g per 100 g, in purple corn kernels and husks. Due to critical differences in origin and extraction methods determining anthocyanin content. The variety known as Indigo Rose became commercially available to the agricultural industry, investing tomatoes with high anthocyanin content doubles their shelf-life and inhibits growth of a post-harvest mold pathogen, Botrytis cinerea. Tomatoes have been modified with transcription factors from snapdragons to produce high levels of anthocyanins in the fruits
Hygrocybe is a genus of agarics in the family Hygrophoraceae. Called waxcaps in English, basidiocarps are often coloured and have waxy to slimy caps, white spores. In Europe they are characteristic of old, unimproved grasslands which are a declining habitat, elsewhere they are more typically found in woodlands. Most are ground-dwelling and all are believed to be moss associates, around 150 species are recognized worldwide. Fruit bodies of several Hygrocybe species are considered edible and are offered for sale in local markets. Hygrocybe was first published in 1821 by Swedish mycologist Elias Magnus Fries as a subsection of Agaricus, in several papers and Murrill used the name Hydrocybe, but this is now taken as an orthographic variant of Hygrocybe. The generic name is derived from the Greek ῦγρὁς + κυβη, Hygrocybe itself has been split into subgenera, several of which – notably Cuphophyllus and Gliophorus Herink – have subsequently been raised to generic rank. Some species, such as the mauve splitting waxcap, have described in the small genus Humidicutis.
Recent molecular research, based on analysis of DNA sequences, suggests that Hygrocybe as currently understood is paraphyletic. As a result, the genus Cuphophyllus was removed from Hygrocybe sensu stricto, fruit bodies of Hygrocybe species are all agaricoid, most having smooth to slightly scaly caps that are convex to conical and waxy to slimy when damp. Many are brightly coloured in shades of red, orange, or yellow – less commonly pink or green, where present, the gills beneath the cap are often equally coloured and usually distant and waxy. One atypical South American species, Hygrocybe aphylla, lacks gills, the stems of Hygrocybe species lack a ring. Fruit bodies of species, notably Hygrocybe conica, blacken with age or when bruised. Microscopically, Hygrocybe species lack true cystidia and have large, smooth. Most species of Hygrocybe are ground-dwelling, though a few are known from mossy tree trunks or logs. In Europe, species are typical of unimproved, short-sward grasslands, often termed waxcap grasslands and their metabolism has long been debated, but recent research shows that they are neither mycorrhizal nor saprotrophic.
It seems they may be associated with mosses, as suggested by several earlier authors. Species are distributed worldwide, from the tropics to the sub-polar regions, around 150 have been described to date
In vitro studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. In contrast, in studies are those conducted in animals, including humans. In vitro studies are conducted using components of an organism that have been isolated from their biological surroundings, such as microorganisms, cells. For example, microrganisms or cells can be studied in artificial culture media, colloquially called test-tube experiments, these studies in biology and their subdisciplines are traditionally done in test tubes, Petri dishes, etc. They now involve the range of techniques used in molecular biology. In contrast, studies conducted in living beings are called in vivo, polymerase chain reaction is a method for selective replication of specific DNA and RNA sequences in the test tube. Protein purification involves the isolation of a protein of interest from a complex mixture of proteins. In vitro fertilization is used to allow spermatozoa to fertilize eggs in a culture dish before implanting the resulting embryo or embryos into the uterus of the prospective mother and these ADME process parameters can be integrated into so called physiologically based pharmacokinetic models or PBPK.
In vitro studies permit a species-specific, more convenient, just as studies in whole animals more and more replace human trials, so are in vitro studies replacing studies in whole animals. This complexity makes it difficult to identify the interactions between individual components and to explore their basic biological functions, in vitro work simplifies the system under study, so the investigator can focus on a small number of components. Another advantage of in vitro methods is that cells can be studied without extrapolation from an experimental animals cellular response. Investigators doing in vitro work must be careful to avoid over-interpretation of their results, for example, scientists developing a new viral drug to treat an infection with a pathogenic virus may find that a candidate drug functions to prevent viral replication in an in vitro setting. However, before this drug is used in the clinic, it must progress through a series of in vivo trials to determine if it is safe and effective in intact organisms.
Results obtained from in vitro experiments cannot usually be transposed, as is, building a consistent and reliable extrapolation procedure from in vitro results to in vivo is therefore extremely important. However, increasingly sophisticated in vitro experiments collect increasingly numerous, mathematical models, such as systems biology models, are much needed here. In pharmacology, IVIVE can be used to approximate pharmacokinetics or pharmacodynamics and that indicates that extrapolating effects observed in vitro needs a quantitative model of in vivo PK. Physiologically based PK models are generally accepted to be central to the extrapolations, in these conditions, developing a simple PD model of the dose–response relationship observed in vitro, and transposing it without changes to predict in vivo effects is not enough
A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist and bacterial cells. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these, the organelle has no basic shape or size, its structure varies according to the needs of the cell. In seeds, stored proteins needed for germination are kept in protein bodies, vacuoles play a major role in autophagy, maintaining a balance between biogenesis and degradation, of many substances and cell structures in certain organisms. They aid in the lysis and recycling of misfolded proteins that have begun to build up within the cell, thomas Boller and others proposed that the vacuole participates in the destruction of invading bacteria and Robert B Mellor proposed organ-specific forms have a role in housing symbiotic bacteria. In protists, vacuoles have the function of storing food which has been absorbed by the organism and assisting in the digestive. The vacuole probably evolved several times independently, even within the Viridiplantae, contractile vacuoles were first observed by Spallanzani in protozoa, although mistaken for respiratory organs.
Dujardin named these stars as vacuoles, in 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuoule membrane as tonoplast, large vacuoles are found in three genera of filamentous sulfur bacteria, the Thioploca and Thiomargarita. The cytosol is extremely reduced in these genera and the vacuole can occupy between 40–98% of the cell, the vacuole contains high concentrations of nitrate ions and is therefore thought to be a storage organelle. Gas vacuoles, which are freely permeable to gas, are present in species of Cyanobacteria. They allow the bacteria to control their buoyancy, most mature plant cells have one large vacuole that typically occupies more than 30% of the cells volume, and that can occupy as much as 80% of the volume for certain cell types and conditions. Strands of cytoplasm often run through the vacuole, a vacuole is surrounded by a membrane called the tonoplast and filled with cell sap.
Also called the membrane, the tonoplast is the cytoplasmic membrane surrounding a vacuole. As a membrane, it is involved in regulating the movements of ions around the cell. The low pH of the vacuole allows degradative enzymes to act, although single large vacuoles are most common, the size and number of vacuoles may vary in different tissues and stages of development. For example, developing cells in the meristems contain small provacuoles and cells of the vascular cambium have many small vacuoles in the winter, aside from storage, the main role of the central vacuole is to maintain turgor pressure against the cell wall. Proteins found in the tonoplast control the flow of water into and out of the vacuole through active transport, pumping potassium ions into, due to osmosis, water will diffuse into the vacuole, placing pressure on the cell wall. If water loss leads to a significant decline in turgor pressure, turgor pressure exerted by the vacuole is essential in supporting plants in an upright position
Europium is a chemical element with symbol Eu and atomic number 63. It was isolated in 1901 and is named after the continent of Europe and it is a moderately hard, silvery metal which readily oxidizes in air and water. Being a typical member of the series, europium usually assumes the oxidation state +3. All europium compounds with oxidation state +2 are slightly reducing, Europium has no significant biological role and is relatively non-toxic compared to other heavy metals. Most applications of europium exploit the phosphorescence of europium compounds, Europium is one of the least abundant elements in the universe, only about 5×10−8% of all matter in the universe is europium. Europium is a metal with a hardness similar to that of lead. It crystallizes in a cubic lattice. Some properties of europium are strongly influenced by its half-filled electron shell, Europium has the second lowest melting point and the lowest density of all lanthanides. Europium becomes a superconductor when it is cooled below 1.8 K and this is because europium is divalent in the metallic state, and is converted into the trivalent state by the applied pressure.
In the divalent state, the local magnetic moment suppresses the superconductivity. Europium is the most reactive rare earth element and it rapidly oxidizes in air, so that bulk oxidation of a centimeter-sized sample occurs within several days. This behavior is unusual to most lanthanides, which almost exclusively form compounds with a state of +3. The +2 state has an electron configuration 4f7 because the half-filled f-shell gives more stability, in terms of size and coordination number and barium are similar. For example, the sulfates of both barium and europium are highly insoluble in water, divalent europium is a mild reducing agent, oxidizing in air to form Eu compounds. In anaerobic, and particularly geothermal conditions, the divalent form is sufficiently stable that it tends to be incorporated into minerals of calcium and the other alkaline earths. This ion-exchange process is the basis of the europium anomaly. Bastnäsite tends to show less of a negative europium anomaly than does monazite, the development of easy methods to separate divalent europium from the other lanthanides made europium accessible even when present in low concentration, as it usually is.
Naturally occurring europium is composed of 2 isotopes, 151Eu and 153Eu, while 153Eu is stable, 151Eu was recently found to be unstable to alpha decay with half-life of 5+11 −3×1018 years, giving about 1 alpha decay per two minutes in every kilogram of natural europium