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Myxobacteria
The myxobacteria ("slime bacteria") are a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes relative to other bacteria, e.g. 9–10 million nucleotides except for '' Anaeromyxobacter'' and ''Vulgatibacter''. One species of myxobacteria, ''Minicystis rosea'', has the largest known bacterial genome with over 16 million nucleotides. The second largest is another myxobacteria '' Sorangium cellulosum''. Myxobacteria can move by gliding. They typically travel in ''swarms'' (also known as ''wolf packs''), containing many cells kept together by intercellular molecular signals. Individuals benefit from aggregation as it allows accumulation of the extracellular enzymes that are used to digest food; this in turn increases feeding efficiency. Myxobacteria produce a number of biomedically and industrially useful chemicals, such as antibiotics, and export those chemicals outside the cell. Myxobacteria are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyangiaceae
The myxobacteria ("slime bacteria") are a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes relative to other bacteria, e.g. 9–10 million nucleotides except for '' Anaeromyxobacter'' and ''Vulgatibacter''. One species of myxobacteria, ''Minicystis rosea'', has the largest known bacterial genome with over 16 million nucleotides. The second largest is another myxobacteria ''Sorangium cellulosum''. Myxobacteria can move by gliding. They typically travel in ''swarms'' (also known as ''wolf packs''), containing many cells kept together by intercellular molecular signals. Individuals benefit from aggregation as it allows accumulation of the extracellular enzymes that are used to digest food; this in turn increases feeding efficiency. Myxobacteria produce a number of biomedically and industrially useful chemicals, such as antibiotics, and export those chemicals outside the cell. Myxobacteria are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxococcus Xanthus
''Myxococcus xanthus'' is a gram-negative, rod-shaped species of myxobacteria that exhibits various forms of self-organizing behavior in response to environmental cues. Under normal conditions with abundant food, it exists as a predatory, saprophytic single-species biofilm called a swarm. Under starvation conditions, it undergoes a multicellular development cycle. Colony growth A swarm of ''M. xanthus'' is a distributed system, containing millions of bacteria that communicate among themselves in a non-centralized fashion. Simple patterns of cooperative behavior among the members of the colony combine to generate complex group behaviors in a process known as " stigmergy". For example, the tendency for one cell to glide only when in direct contact with another results in the colony forming swarms called "wolf-packs" that may measure up to several inches wide. This behavior is advantageous to the members of the swarm, as it increases the concentration of extracellular digestive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorangium Cellulosum
''Sorangium cellulosum'' is a soil-dwelling Gram-negative bacterium of the group myxobacteria. It is motile and shows gliding motility. Under stressful conditions this motility, as in other myxobacteria, the cells congregate to form fruiting bodies and differentiate into myxospores. These congregating cells make isolation of pure culture and colony counts on agar medium difficult as the bacterium spread and colonies merge. It has an unusually-large genome of 13,033,779 base pairs, making it the largest bacterial genome sequenced to date by roughly 4 Mb. Ecology ''S. cellulosum'' is found in soils, animal feces, and tree bark. The bacterium is a saprophyte deriving its nutrition from cellulose aerobically. It is a prolific producer of secondary fungicides and bactericides that reduce competition in soil environments. In lab samples, ''S. cellulosum'' grows on agar medium only when certain cell densities are plated. Quorum-sensing allows Sorangium to grow in communities suffici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pxr SRNA
Pxr sRNA is a regulatory RNA which downregulates genes responsible for the formation of fruiting bodies in ''Myxococcus xanthus''. Fruiting bodies are aggregations of myxobacteria formed when nutrients are scarce, the fruiting bodies permit a small number of the aggregated colony to transform into stress-resistant spores. Pxr exists in two forms: Pxr-L (a long form) and Pxr-S which is shorter. The short form was found to be expressed in cells during growth but is rapidly repressed during starvation. This finding implies that Pxr-S is specifically responsible for inhibiting the fruiting body development during cell growth when nutrients are abundant. Pxr homologs have only been found in one other taxon, namely '' Stigmatella aurantiaca''. Homologs were not found in any other myxobacteria (such as '' Sorangium cellulosum'' or ''Anaeromyxobacter dehalogenans'') which suggests the Pxr RNA gene may have a recent evolutionary origin in the sub-clade Myxococcales. PxR sRNA folds into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Gliding
Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of this motility are only partially known. Twitching motility also allows microorganisms to travel along a surface, but this type of movement is jerky and uses pili as its means of transport. Bacterial gliding is a type of gliding motility that can also use pili for propulsion. The speed of gliding varies between organisms, and the reversal of direction is seemingly regulated by some sort of internal clock. For example the apicomplexans are able to travel at fast rates between 1–10 µm/s. In contrast ''Myxococcus xanthus'' bacteria glide at a rate of 0.08 µm/s. Cell-invasion and gliding motility have TRAP (thrombospondin-related anonymous protein), a surface protein, as a common molecular basis that is both essential for in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxococcaceae
Myxococcaceae is a family of gram-negative, rod-shaped bacteria. The family Myxococcaceae is encompassed within the myxobacteria ("slime bacteria"). The family is ubiquitously found in soils, marine, and freshwater environments. Production of compounds with medical uses by Myxococcaceae makes them useful in human health fields. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) Morphology and Behavior Cells can be motile with gliding and swarming behavior. The vegetative cell shape in the Myxococcaceae family is long rods, which vary in size between members. The most common fruiting body morphs are soft hump and knob shaped with possible colors of yellow, peach, white, or orange depending on species. Myxococcaceae are spore producing bacteria and are delineated by their spore shape. The myxospores are oval to round and are optically refractive. Quoru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archangiaceae
Myxococcaceae is a family of gram-negative, rod-shaped bacteria. The family Myxococcaceae is encompassed within the myxobacteria ("slime bacteria"). The family is ubiquitously found in soils, marine, and freshwater environments. Production of compounds with medical uses by Myxococcaceae makes them useful in human health fields. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) Morphology and Behavior Cells can be motile with gliding and swarming behavior. The vegetative cell shape in the Myxococcaceae family is long rods, which vary in size between members. The most common fruiting body morphs are soft hump and knob shaped with possible colors of yellow, peach, white, or orange depending on species. Myxococcaceae are spore producing bacteria and are delineated by their spore shape. The myxospores are oval to round and are optically refractive. Quoru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular Organism
A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus '' Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also multinucleate though technically unicellular organisms that are macroscopic, such as the xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has evolve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swarm
Swarm behaviour, or swarming, is a collective behaviour exhibited by entities, particularly animals, of similar size which aggregate together, perhaps milling about the same spot or perhaps moving ''en masse'' or migrating in some direction. It is a highly interdisciplinary topic. As a term, ''swarming'' is applied particularly to insects, but can also be applied to any other entity or animal that exhibits swarm behaviour. The term '' flocking'' or ''murmuration'' can refer specifically to swarm behaviour in birds, '' herding'' to refer to swarm behaviour in tetrapods, and ''shoaling'' or ''schooling'' to refer to swarm behaviour in fish. Phytoplankton also gather in huge swarms called ''blooms'', although these organisms are algae and are not self-propelled the way animals are. By extension, the term "swarm" is applied also to inanimate entities which exhibit parallel behaviours, as in a robot swarm, an earthquake swarm, or a swarm of stars. From a more abstract point of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
