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Mollicutes
Mollicutes is a class of bacteria distinguished by the absence of a cell wall and its peptidoglycan. The word "Mollicutes" is derived from the Latin ' (meaning "soft" or "pliable"), and ' (meaning "skin"). Individuals are very small, typically only 0.2–0.3 micrometre, μm (200–300 nanometer, nm) in size and have a very small genome size. They vary in form, although most have sterols that make the cell membrane somewhat more rigid. Many are able to move about through bacterial gliding, gliding, but members of the genus ''Spiroplasma'' are helical and move by twisting. The best-known genus in the Mollicutes is ''Mycoplasma'', though it has been split in 2018 into several genera. Colonies show the typical "fried-egg" appearance. Mollicutes can be parasitic or saprotrophic. They can be parasites of various animals and plants, living on or in the host's cells. Many cause diseases in humans, attaching to cells in the respiratory or urogenital tracts, particularly species of ''Mycopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycoplasma
''Mycoplasma'' is a genus of bacteria that, like the other members of the class ''Mollicutes'', lack a cell wall, and its peptidoglycan, around their cell membrane. The absence of peptidoglycan makes them naturally resistant to antibiotics such as the beta-lactam antibiotics that target cell wall synthesis. They can be parasitic or saprotrophic. In casual speech, the name ''"mycoplasma"'' (plural ''mycoplasmas'' or ''mycoplasms'') generally refers to all members of the class Mollicutes. In formal scientific classification, the designation ''Mycoplasma'' refers exclusively to the genus, a member of the Mycoplasmataceae, the only family in the order Mycoplasmatales (see "scientific classification"). In 2018, ''Mycoplasma'' was split with many clinically significant species moved to other genera in Mollicutes; see the page Mollicutes for an overview. Etymology The term "mycoplasma", from the Greek μύκης, ' (fungus) and πλάσμα, ' (formed), was first used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoplasma
Phytoplasmas are obligate intracellular parasites of plant phloem tissue and of the insect vectors that are involved in their plant-to-plant transmission. Phytoplasmas were discovered in 1967 by Japanese scientists who termed them mycoplasma-like organisms. Since their discovery, phytoplasmas have resisted all attempts at ''in vitro'' culture in any cell-free medium; routine cultivation in an artificial medium thus remains a major challenge. Phytoplasmas are characterized by the lack of a cell wall, a pleiomorphic or filamentous shape, a diameter normally less than 1 μm, and a very small genome. Phytoplasmas are pathogens of agriculturally important plants, including coconut, sugarcane, sandalwood, and cannabis, as well as horticultural crops like sweet cherry, peaches, and nectarines. They cause a wide variety of symptoms ranging from mild yellowing, small fruit, and reduced sugar content to death. Phytoplasmas are most prevalent in tropical and subtropical regions. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiroplasma
''Spiroplasma'' is a genus of Mollicutes, a group of small bacteria without cell walls. ''Spiroplasma'' shares the simple metabolism, parasitic lifestyle, fried-egg colony morphology and small genome of other ''Mollicutes'', but has a distinctive helical morphology, unlike ''Mycoplasma''. It has a spiral shape and moves in a corkscrew motion. Many ''Spiroplasma'' are found either in the gut or haemolymph of insects where they can act to manipulate host reproduction, or defend the host as endosymbionts. ''Spiroplasma'' are also disease-causing agents in the phloem of plants. Spiroplasmas are fastidious organisms, which require a rich culture medium. Typically they grow well at 30 °C, but not at 37 °C. A few species, notably '' Spiroplasma mirum'', grow well at 37 °C (human body temperature), and cause cataracts and neurological damage in suckling mice. The best studied species of spiroplasmas are '' Spiroplasma poulsonii'', a reproductive manipulator and defensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycoplasmoides Pneumoniae
''Mycoplasma pneumoniae'' is a species of very small-cell bacteria that lack a cell wall, in the class Mollicutes. ''M. pneumoniae'' is a human pathogen that causes the disease Mycoplasma pneumonia, a form of atypical bacterial pneumonia related to cold agglutinin disease. It is one of the smallest self-replicating organisms and its discovery traces back to 1898 when Nocard and Roux isolated a microorganism linked to cattle pneumonia. This microbe shared characteristics with pleuropneumonia-like organisms (PPLOs), which were soon linked to pneumonias and arthritis in several animals. A significant development occurred in 1944 when Monroe Eaton cultivated an agent thought responsible for human pneumonia in embryonated chicken eggs, referred to as the "Eaton agent." This agent was classified as a bacteria due to its cultivation method and because antibiotics were effective in treating the infection, questioning its viral nature. In 1961, a researcher named Robert Chanock, collabo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaeroplasmatales
Anaeroplasmatales is an order of mollicute bacteria which are generally found in the rumens of cattle and sheep. The only family in the order is the family Anaeroplasmataceae. Description Members of the order Anaeroplasmatales can appear as different shapes at different times in their lifecycles. Cells which are 16–18 hours old tend to be spherical. When the cells are older, they can take on various shapes. Anaeroplasmatales are not motile. Anaeroplasmatales cannot grow in the presence of oxygen. They do grow at a temperature of 37 °C on microbiological media, where they form irregular-shaped colonies with a "fried-egg" appearance, similar to other mycoplasmas. Anaeroplasmatales are negative by Gram stain. History The order Anaeroplasmatales was created in 1987 to encompass the family Anaeroplasmataceae which itself was created to hold the anaerobic mycoplasmas '' Anaeroplasma'' and '' Asteroleplasma''. Phylogeny The currently accepted taxonomy is based on the List of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycoplasmatales
Mycoplasmatales is an order of bacteria in the class Mollicutes. The order consists of the families Spiroplasmataceae and Mycoplasmataceae. As currently (2025) defined by LPSN, this class is synonymous to Entomoplasmatales, a class originally intended to include the arthropod-associated mollicutes. Newer phylogenetic studies have found that Entomoplasmatales was not monophyletic like Tully had believed, but paraphyletic. The family Entomoplasmataceae of Tully was also paraphyletic by the exclusion of ''Mycoplasma''. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ... (NCBI). References Mollicutes Bacte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acholeplasmatales
Acholeplasmataceae is a family of bacteria. It is the only family in the order Acholeplasmatales, placed in the class Mollicutes. The family comprises the genera '' Acholeplasma'' and ''Phytoplasma''. ''Phytoplasma'' has the candidatus status, because members still could not be cultured. Etymology: The names Acholeplasmataceae and Acholetoplasmatales are derived from the Greek ''a'' = not, ''cholè'' = bile and ''plasma'' = anything moulded or formed.D.G. Edward, E.A. Freund''Amended nomenclature for strains related to Mycoplasma laidlawii.'' J Gen Microbiol. 1970 Jul; 62PDF/ref> Species in the order Acholeplasmatales can grow in a medium without cholesterol, unlike species in the order Mycoplasmatales. Cholesterol, a sterol, is an important component of the cell membrane of mycoplasmas, whereas in acholeplasmas and in bacteria in general it is absent. Characteristics Members of Acholeplasmatales are facultative anaerobic. They are parasites or commensals of vertebrates, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haloplasmatales
''Haloplasma contractile'' is a halophilic, cell wall-less bacterium. It is the only known representative of a deep lineage, and is classified in its own family (Haloplasmataceae) and order (Haloplasmatales), in the class Mollicutes. In terms of genetics, the bacterium Haloplasma contractile contains a dcw gene cluster is responsible for containing all the genes of the organism and promoting peptidoglycan synthesis. Also, MreB/Mbl are specific homologous parts of this bacterium that are vital in the contractility of the cell. Regarding its physical attributes, this organism consists of a spherical body with approximately two protrusions which alternate between straight and contracted forms. See also * List of Bacteria genera * List of bacterial orders This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) and the phylog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L-form Bacteria
L-form bacteria, also known as L-phase bacteria, L-phase variants or cell wall-deficient bacteria (CWDB), are growth forms derived from different bacteria. They lack cell walls. Two types of L-forms are distinguished: ''unstable L-forms'', spheroplasts that are capable of dividing, but can revert to the original morphology, and ''stable L-forms'', L-forms that are unable to revert to the original bacteria. Discovery and early studies L-form bacteria were first isolated in 1935 by Emmy Klieneberger-Nobel, who named them "L-forms" after the Lister Institute in London where she was working. She first interpreted these growth forms as symbionts related to pleuropneumonia-like organisms (PPLOs, later commonly called mycoplasmas). Mycoplasmas (now in scientific classification called '' Mollicutes''), parasitic or saprotrophic species of bacteria, also lack a cell wall (peptidoglycan/murein is absent).&nbsFull PDF/ref> Morphologically, they resemble L-form bacteria. Therefore, myco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acholeplasma Palmae
''Acholeplasma'' are wall-less bacteria in the Mollicutes class. They include saprotrophic or pathogenic species. There are 15 recognised species. The G+C content is low, ranging from 26 – 36% ( mol%). The genomes of ''Acholeplasma'' species range in size from 1.5 to 1.65 Mbp. Cholesterol is not required for growth. The species are found on animals, and some plants and insects. The optimum growth temperature is 30 to 37 degrees Celsius. ''Acholeplasma laidlawii'' is a common contaminant of cell culture media products, and has also been used in extensive studies of lipid polymorphism because this organism alters its ratio of MGlcDG (monoglucosyl diacylglycerol) to DGlcDG (diglucosyl diacylglycerol) in response to growth conditions. Phylogeny See also * List of bacteria genera * List of bacterial orders This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Cen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycoplasmoidales
Mycoplasmoidales is an order of bacteria in the class Mollicutes. The order consists of the families Mycoplasmoidaceae (formerly the "pneumoniae" group) and Metamycoplasmataceae (formerly the "hominis" group). It includes most human pathogens formerly classified in the genus ''Mycoplasma''. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ... (NCBI). References {{Taxonbar, from=Q123359009 Mollicutes Bacteria orders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most Prokaryote, prokaryotes, with the exception of Mollicutes, mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In Embryophyte, land plants, the primary cell wall comprises Polysaccharide, polysaccharides like cellulose, hemicelluloses, and pectin. Often, other Polymer, polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
