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72-746: Halobacterium (common abbreviation Hbt. ) is a genus in the family Halobacteriaceae . The genus Halobacterium ("salt" or "ocean bacterium") consists of several species of Archaea with an aerobic metabolism which requires an environment with a high concentration of salt ; many of their proteins will not function in low-salt environments. They grow on amino acids in their aerobic conditions. Their cell walls are also quite different from those of bacteria , as ordinary lipoprotein membranes fail in high salt concentrations. In shape, they may be either rods or cocci , and in color, either red or purple. They reproduce using binary fission (by constriction), and are motile . Halobacterium grows best in

144-656: A homolog of the rad51 / recA gene, which plays a key role in recombination, is induced 7-fold by UV. Homologous recombination may rescue stalled replication forks, and/or facilitate recombinational repair of DNA damage. In its natural habitat, homologous recombination is likely induced by the UV irradiation in sunlight. Halobacterium volcanii has a distinctive mating system in which cytoplasmic bridges between cells appear to be used for transfer of DNA from one cell to another. In wild populations of Halorubrum , genetic exchange and recombination occur frequently. This exchange may be

216-429: A model organism in biological studies. Furthermore, Halobacterium NRC-1 have also been employed as a potential vector for delivering vaccines. In particular, they produce gas vesicles that can be genetically engineered to display specific epitopes. Additionally, the gas vesicles demonstrate the ability to function as natural adjuvants to help evoke stronger immune responses. Because of the requirement of Halobacteria for

288-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in the nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

360-430: A 42 °C environment. The genome of an unspecified Halobacterium species, sequenced by Shiladitya DasSarma , comprises 2,571,010 bp ( base pairs ) of DNA compiled into three circular strands: one large chromosome with 2,014,239 bp, and two smaller ones with 191,346 and 365,425 bp. This species, called Halobacterium sp. NRC-1, has been extensively used for postgenomic analysis. Halobacterium species can be found in

432-457: A contaminant in some high salinity industrial runoffs. Some strains of Halobacterium , including Halobacterium salinarum , are being explored for medical applications of their radiation-resistance mechanisms. Bacterioruberin is a carotenoid pigment found in Halobacterium which decreases the bacteria’s sensitivity to γ-radiation and UV radiation. It has been shown in knockout studies, that

504-476: A fatty acid oxidation pathway, it does not seem able to use these as energy sources. Though the cytoplasm retains an osmotic equilibrium with the hypersaline environment, the cell maintains a high potassium concentration using many active transporters. Many Halobacterium species possess proteinaceous organelles called gas vesicles. Halobacteria can be found in highly saline lakes such as the Great Salt Lake,

576-459: A high blood β-carotene value. This can occur after a month or two of consumption of beta-carotene rich foods, such as carrots, carrot juice, tangerine juice, mangos, or in Africa, red palm oil. β-carotene dietary supplements can have the same effect. The discoloration extends to palms and soles of feet, but not to the white of the eye , which helps distinguish the condition from jaundice . Carotenodermia

648-1116: A high-salt environment, the preparation of these gas vesicles is inexpensive and efficient, needing only tap water for their isolation. Halobacteria also contain a protein called Bacteriorhodopsins which are light-driven proton pumps found on the cell membrane. Although most proteins in halophiles need high salt concentrations for proper structure and functioning, this protein has shown potential to be used for biotechnological purposes because of its stability even outside of these extreme environments. Bacteriorhodopsins isolated from Halobacterium salinarum have been especially studied for their applications in electronics and optics. Particularly, bacteriorhodopsins have been used in holographic storage, optical switching, motion detection, and nanotechnology . Although numerous uses of this protein have been presented, there are yet to be any high-scale commercial applications established at this time. UV irradiation of Halobacterium sp. strain NRC-1 induces several gene products employed in homologous recombination . For instance,

720-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

792-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

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864-443: A lower risk of all-cause mortality. The highest circulating beta-carotene category, compared to the lowest, correlated with a 37% reduction in the risk of all-cause mortality, while the highest dietary beta-carotene intake category, compared to the lowest, was linked to an 18% decrease in the risk of all-cause mortality. Age-related macular degeneration (AMD) represents the leading cause of irreversible blindness in elderly people. AMD

936-497: A primitive form of sexual interaction, similar to the more well studied bacterial transformation that is also a process for transferring DNA between cells leading to homologous recombinational repair of DNA damage. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including

1008-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

1080-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1152-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

1224-413: Is carotenodermia , a physically harmless condition that presents as a conspicuous orange skin tint arising from deposition of the carotenoid in the outermost layer of the epidermis . Carotenoderma , also referred to as carotenemia, is a benign and reversible medical condition where an excess of dietary carotenoids results in orange discoloration of the outermost skin layer. It is associated with

1296-461: Is 2,571,010 bp compiled into three circular replicons . More specifically, it is divided into one large chromosome with 2,014,239 bp and two small replicons pNRC100 (191,346 bp) and pNRC200 (365,425 bp). While much smaller than the large chromosome, the two plasmids account for most of the 91 insertion sequences and include genes for a DNA polymerase , seven transcription factors , genes in potassium and phosphate uptake, and cell division. The genome

1368-454: Is a pro vitamin A compound, converting in the body to retinol (vitamin A). In foods, it has rich content in carrots , pumpkin , spinach , and sweet potato . It is used as a dietary supplement and may be prescribed to treat erythropoietic protoporphyria , an inherited condition of sunlight sensitivity. β-carotene is the most common carotenoid in plants. When used as a food coloring , it has

1440-450: Is an oxidative stress, retinal disease that affects the macula, causing progressive loss of central vision. β-carotene content is confirmed in human retinal pigment epithelium. Reviews reported mixed results for observational studies, with some reporting that diets higher in β-carotene correlated with a decreased risk of AMD whereas other studies reporting no benefits. Reviews reported that for intervention trials using only β-carotene, there

1512-519: Is associated with a 6% increase in the risk of all-cause mortality , while low-dosage (<9.6 mg/day) supplementation does not have a significant effect on mortality. Research is insufficient to determine whether a minimum level of beta-carotene consumption is necessary for human health and to identify what problems might arise from insufficient beta-carotene intake. However, a 2018 meta-analysis mostly of prospective cohort studies found that both dietary and circulating beta-carotene are associated with

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1584-599: Is being able to grow at a low temperature during a presumably short time when a pool of water could be liquid. There is potential for Halobacterium species to be used in the food industry. Some examples of uses can include the production of Beta-Carotene , a pigment in halophilic bacteria that contributes to their red coloration, is used in the food industry as a natural food dye. Halophiles also produce degradative enzymes such as lipases , amylases , proteases , and xylanases that are used in various food processing methods. Notable applications of these enzymes include enhancing

1656-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

1728-601: Is encoded by the BCO1 gene. A lesser amount is metabolized by the mitochondrial enzyme beta-carotene 9',10'-dioxygenase, which is encoded by the BCO2 gene. The products of this asymmetric cleavage are two beta-ionone molecules and rosafluene. BCO2 appears to be involved in preventing excessive accumulation of carotenoids; a BCO2 defect in chickens results in yellow skin color due to accumulation in subcutaneous fat. For counting dietary vitamin A intake, β-carotene may be converted either using

1800-472: Is greater bioavailability compared to that from foods. At the enterocyte cell wall, β-carotene is taken up by the membrane transporter protein scavenger receptor class B, type 1 (SCARB1). Absorbed β-carotene is then either incorporated as such into chylomicrons or first converted to retinal and then retinol, bound to retinol binding protein 2 , before being incorporated into chylomicrons. The conversion process consists of one molecule of β-carotene cleaved by

1872-517: Is industrially made either by total synthesis (see Retinol § Industrial synthesis ) or by extraction from biological sources such as vegetables, microalgae (especially Dunaliella salina ), and genetically-engineered microbes. The synthetic path is low-cost and high-yield. Medical authorities generally recommend obtaining beta-carotene from food rather than dietary supplements. A 2013 meta-analysis of randomized controlled trials concluded that high-dosage (≥9.6 mg/day) beta-carotene supplementation

1944-469: Is masked by chlorophyll in green leaf vegetables such as spinach , kale , sweet potato leaves, and sweet gourd leaves. The U.S. Department of Agriculture lists foods high in β-carotene content: Milligrams per 100 g Government and non-government organizations have not set a dietary requirement for β-carotene. Excess β-carotene is predominantly stored in the fat tissues of the body. The most common side effect of excessive β-carotene consumption

2016-579: Is reversible upon cessation of excessive intake. Consumption of greater than 30 mg/day for a prolonged period has been confirmed as leading to carotenemia. At the enterocyte cell wall, β-carotene is taken up by the membrane transporter protein scavenger receptor class B, type 1 (SCARB1). Absorbed β-carotene is then either incorporated as such into chylomicrons or first converted to retinal and then retinol, bound to retinol binding protein 2 , before being incorporated into chylomicrons. The conversion process consists of one molecule of β-carotene cleaved by

2088-406: Is separated with a non-polar solvent such as hexane . Being highly conjugated , it is deeply colored, and as a hydrocarbon lacking functional groups, it is lipophilic . Plant carotenoids are the primary dietary source of provitamin A worldwide, with β-carotene as the best-known provitamin A carotenoid. Others include α-carotene and β-cryptoxanthin . Carotenoid absorption is restricted to

2160-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

2232-411: Is specific to supplementation dose as no lung damage has been detected in those who are exposed to cigarette smoke and who ingest a physiological dose of β-carotene (6 mg), in contrast to high pharmacological dose (30 mg). . Increases in lung cancer have been attributed to the tendency of β-carotene to oxidize, yet based on the pharmacokinetics of β-carotene absorption and transport through

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2304-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

2376-409: The E number E160a. The structure was deduced in 1930. Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography . It is industrially extracted from richer sources such as the algae Dunaliella salina . The separation of β-carotene from the mixture of other carotenoids is based on the polarity of a compound. β-Carotene is a non-polar compound, so it

2448-574: The Great Salt Lake , the Dead Sea , Lake Magadi , and any other waters with high salt concentration. Purple Halobacterium species owe their color to bacteriorhodopsin , a light-sensitive protein which provides chemical energy for the cell by using sunlight to pump protons out of the cell. The resulting proton gradient across the cell membrane is used to drive the synthesis of the energy carrier ATP . Thus, when these protons flow back in, they are used in

2520-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

2592-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

2664-479: The duodenum of the small intestine . One molecule of β-carotene can be cleaved by the intestinal enzyme β,β-carotene 15,15'-monooxygenase into two molecules of vitamin A. As part of the digestive process, food-sourced carotenoids must be separated from plant cells and incorporated into lipid-containing micelles to be bioaccessible to intestinal enterocytes . If already extracted (or synthetic) and then presented in an oil-filled dietary supplement capsule, there

2736-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

2808-453: The Dead Sea, and Lake Magadi. Halobacterium can be identified in bodies of water by the light-detecting pigment bacteriorhodopsin, which not only provides the archaeon with chemical energy, but adds to its reddish hue as well. An optimal temperature for growth has been observed at 37 °C. Halobacterium may be a candidate for a life form present on Mars. One of the problems associated with

2880-469: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or the scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of

2952-564: The absence of bacterioruberin increases the sensitivity of the bacterium to oxidative DNA-damaging agents. Hydrogen peroxide, for example, reacts with bacteroruberin which prevents the production of reactive oxygen species , and thus protects the bacterium by reducing the oxidative capacity of the DNA-damaging agent. H. salinarum also exhibits high intracellular concentrations of potassium chloride which has also been shown to confer radiation resistance. Halobacterium are also being explored for

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3024-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

3096-468: The bioremediation of xenobiotic compounds and heavy metals that are released into the environment from mining and metal plating. Halophiles contribute to the bioremediation of contaminants by converting xenobiotics into less toxic compounds. Some Halobacterium species have been shown to be effective in the bioremediation of pollutants including aliphatic hydrocarbons, such as those found in crude oil; and aromatic hydrocarbons such as 4-hydroxybenzoic acid ,

3168-446: The chylomicrons that bypassed the liver, β-carotene is taken into cells via receptor SCARB1. Human tissues differ in expression of SCARB1, and hence β-carotene content. Examples expressed as ng/g, wet weight: liver=479, lung=226, prostate=163 and skin=26. Once taken up by peripheral tissue cells, the major usage of absorbed β-carotene is as a precursor to retinal via symmetric cleavage by the enzyme beta-carotene 15,15'-dioxygenase, which

3240-512: The effectiveness of these medications and is considered only a moderate interaction. Bile acid sequestrants and proton-pump inhibitors can decrease absorption of β-carotene. Consuming alcohol with β-carotene can decrease its ability to convert to retinol and could possibly result in hepatotoxicity . Chronic high doses of β-carotene supplementation increases the probability of lung cancer in smokers while its natural vitamer, retinol, increases lung cancer in smokers and nonsmokers. The effect

3312-471: The enzyme beta-carotene 15,15'-dioxygenase , which is encoded by the BCO1 gene, into two molecules of retinal. When plasma retinol is in the normal range the gene expression for SCARB1 and BCO1 are suppressed, creating a feedback loop that suppresses β-carotene absorption and conversion. The majority of chylomicrons are taken up by the liver, then secreted into the blood repackaged into low density lipoproteins (LDLs). From these circulating lipoproteins and

3384-471: The enzyme beta-carotene 15,15'-dioxygenase , which is encoded by the BCO1 gene, into two molecules of retinal. When plasma retinol is in the normal range the gene expression for SCARB1 and BCO1 are suppressed, creating a feedback loop that suppresses absorption and conversion. Because of these two mechanisms, high intake will not lead to hypervitaminosis A . β-Carotene can interact with medication used for lowering cholesterol . Taking them together can lower

3456-483: The fermentation process of salty foods, improving dough quality for the baking of breads, and contributing to the production of coffee. Many species of halophilic bacteria produce exopolysaccharides (EPS) which are used industrially as bioremediation agents. Biosurfactants are also released by many halophilic bacteria and these amphiphilic compounds have been used for soil remediation. Many halophiles are highly tolerant of heavy metals making them potentially useful in

3528-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

3600-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

3672-432: The idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of the same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but

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3744-515: The intestine and the lack of specific β-carotene transporters, it is unlikely that β-carotene reaches the lung of smokers in sufficient quantities. Additional research is required to understand the link between the increased risk of cancer and all-cause mortality following β-carotene supplementation. Additionally, supplemental, high-dose β-carotene may increase the risk of prostate cancer , intracerebral hemorrhage , and cardiovascular and total mortality irrespective of smoking status. β-carotene

3816-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

3888-503: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Beta-Carotene β-Carotene ( beta -carotene) is an organic , strongly colored red-orange pigment abundant in fungi, plants, and fruits. It is a member of the carotenes , which are terpenoids (isoprenoids), synthesized biochemically from eight isoprene units and thus having 40 carbons . Dietary β-carotene

3960-411: The loss of visual acuity. These studies found no evidence of any protective effects afforded by β-carotene supplementation on preventing and slowing age-related cataract. A second meta-analysis compiled data from studies that measured diet-derived serum beta-carotene and reported a not statistically significant 10% decrease in cataract risk. High doses of β-carotene (up to 180 mg per day) may be used as

4032-738: The more useful retinol activity equivalent as follows: The average daily intake of β-carotene is in the range 2–7 mg, as estimated from a pooled analysis of 500,000 women living in the US, Canada, and some European countries. Beta-carotene is found in many foods and is sold as a dietary supplement . β-Carotene contributes to the orange color of many different fruits and vegetables. Vietnamese gac ( Momordica cochinchinensis Spreng.) and crude palm oil are particularly rich sources, as are yellow and orange fruits, such as cantaloupe , mangoes , pumpkin , and papayas , and orange root vegetables such as carrots and sweet potatoes . The color of β-carotene

4104-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

4176-414: The most lateral genetics (gene transfer between domains) and a proof that this transfer does take place. Halobacterium species are rod-shaped and enveloped by a single lipid bilayer membrane surrounded by an S-layer made from the cell-surface glycoprotein. They grow on amino acids in aerobic conditions. Although Halobacterium NRC-1 contains genes for glucose degradation, as well as genes for enzymes of

4248-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

4320-542: The newer retinol activity equivalents (RAE) or the older international unit (IU). Since 2001, the US Institute of Medicine uses retinol activity equivalents (RAE) for their Dietary Reference Intakes, defined as follows: RAE takes into account carotenoids' variable absorption and conversion to vitamin A by humans better than and replaces the older retinol equivalent (RE) (1 μg RE = 1 μg retinol, 6 μg β-carotene, or 12 μg α-carotene or β-cryptoxanthin). RE

4392-792: The pharmaceutical applications of bioactive compounds they produce, including anticancer agents, antimicrobial biosurfactancts, and antimicrobial metabolites. Halobacteria are halophilic microorganisms that are currently being studied for their uses in scientific research and biotechnology. For instance, genomic sequencing of the Halobacterium species NRC-1 revealed their use of eukaryotic-like RNA polymerase II and translational machinery that are related to Escherichia coli and other Gram-negative bacteria. In addition, they possess genes for DNA replication, repair, and recombination that are similar to those present in bacteriophages, yeasts, and bacteria. The ability of this Halobacterium species to be easily cultured and genetically modified allows it to be used as

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4464-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

4536-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

4608-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

4680-547: The survival on Mars is the destructive ultraviolet light. These microorganisms develop a thin crust of salt that can moderate some of the ultraviolet light. Sodium chloride is the most common salt and chloride salts are opaque to short-wave ultraviolet. Their photosynthetic pigment, bacteriorhodopsin, is actually opaque to the longer-wavelength ultraviolet (its red color). In addition, Halobacterium makes pigments called bacterioruberins that are thought to protect cells from damage by ultraviolet light. The obstacle they need to overcome

4752-1003: The synthesis of ATP (this proton flow can be emulated with a decrease in pH outside the cell, causing a flow of H ions). The bacteriorhodopsin protein is chemically very similar to the light-detecting pigment rhodopsin, found in the vertebrate retina . The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). H. zhouii Wang et al. 2023 H. litoreum Lu et al. 2017 H. bonnevillei Myers & King 2020 H. noricense Gruber et al. 2005 H. wangiae Wang et al. 2023 H. jilantaiense Yang et al. 2006 H. rubrum Han & Cui 2015 H. salinarum H. bonnevillei " H. hubeiense " Jaakkola et al. 2016 H. noricense H. litoreum H. jilantaiense H. salinarum The Halobacterium NRC-1 genome

4824-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

4896-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

4968-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

5040-573: Was developed 1967 by the United Nations/ World Health Organization Food and Agriculture Organization (FAO/WHO). Another older unit of vitamin A activity is the international unit (IU). Like retinol equivalent, the international unit does not take into account carotenoid variable absorption and conversion to vitamin A by humans, as well as the more modern retinol activity equivalent. Unfortunately, food and supplement labels still generally use IU, but IU can be converted to

5112-419: Was discovered to contain a high G+C content at 67.9% on the large chromosome and 57.9% and 59.2% on the two plasmids. The genome also contained 91 insertion sequence elements constituting 12 families, including 29 on pNRC100, 40 on pNRC200, and 22 on the large chromosome. This helps explain the genetic plasticity that has been observed in Halobacterium . Of the archaea, halobacteria are viewed as being involved in

5184-646: Was no change to risk of developing AMD. A meta-analysis concluded that supplementation with β-carotene does not appear to decrease the risk of cancer overall, nor specific cancers including: pancreatic, colorectal, prostate, breast, melanoma, or skin cancer generally. High levels of β-carotene may increase the risk of lung cancer in current and former smokers. Results are not clear for thyroid cancer. A Cochrane review looked at supplementation of β-carotene, vitamin C, and vitamin E, independently and combined, on people to examine differences in risk of cataract , cataract extraction, progression of cataract, and slowing

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