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Deinococcus
''Deinococcus'' (from the , ''deinos'', "dreadful, strange" and κόκκος, ''kókkos'', "granule") is in the formerly monotypic family Deinococcaceae, and one genus of three in the order Deinococcales of the bacterial phylum '' Deinococcota'' highly resistant to environmental hazards. These bacteria have thick cell walls that give them Gram-positive stains, but they also include a second membrane and are therefore closer in structure to Gram-negative bacteria. ''Deinococcus'' survive when their DNA is exposed to high doses of gamma and UV radiation. Whereas other bacteria change their structure in the presence of radiation, such as by forming endospores, ''Deinococcus'' tolerate it without changing their cellular form and do not retreat into a hardened structure. They are also characterized by the presence of the carotenoid pigment deinoxanthin that give them their pink color. They are usually isolated according to these two criteria. In August 2020, scientists reported that ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcus Radiodurans
''Deinococcus radiodurans'' is a bacterium, an extremophile and one of the most radiation-resistant organisms known. It can survive cold, dehydration, vacuum, and acid, and therefore is known as a polyextremophile. ''The Guinness Book Of World Records'' listed it in January 1998 as the world's most radiation-resistant bacterium or lifeform. Several bacteria of comparable radioresistance are known, including some species of the genus '' Chroococcidiopsis'' (phylum cyanobacteria) and some species of '' Rubrobacter'' (phylum Actinomycetota); among the archaea, the species '' Thermococcus gammatolerans'' shows comparable radioresistance. Name and classification The name ''Deinococcus radiodurans'' derives from the Ancient Greek δεινός () and κόκκος () meaning "terrible grain/berry" and the Latin and , meaning "radiation-surviving". The species was formerly called ''Micrococcus radiodurans''. As a consequence of its hardiness, it has been nicknamed “Conan the Bacteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcota
Deinococcota (synonym, Deinococcus-Thermus) is a phylum of bacteria with a single class, ''Deinococci'', that are highly resistant to environmental hazards, also known as extremophiles. These bacteria have thick cell walls that give them gram-positive stains, but they include a second membrane and so are closer in structure to those of gram-negative bacteria. Taxonomy The phylum Deinococcota consists of a single class ( Deinococci) and two orders: * The Deinococcales include two families ( Deinococcaceae and Trueperaceae), with three genera, '' Deinococcus'', '' Deinobacterium'' and '' Truepera''.Garrity GM, Holt JG. (2001) Phylum BIV. "Deinococcus–Thermus". In: Bergey’s manual of systematic bacteriology, pp. 395-420. Eds D. R. Boone, R. W. Castenholz. Springer-: New York.Garrity GM, Bell JA, Lilburn TG. (2005) Phylum BIV. The revised road map to the Manual. In: Bergey’s manual of systematic bacteriology, pp. 159-220. Eds Brenner DJ, Krieg NR, Staley JT, Garrity GM. Sprin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcus Geothermalis
''Deinococcus geothermalis'' is a non-pathogenic, sphere-shaped, Gram-positive, heterotrophic bacterium, where geothermalis means 'hot earth' or 'hot springs'. This bacterium was first obtained from the hot springs of Agnano, Naples, Italy and São Pedro do Sul, Portugal. It resides primarily in hot springs and in deep ocean environments. Genome Structure ''Deinococcus geothermalis'' has a genome that contains 2.47 Mbp with 2,335 protein coding genes. There are 73 insertion sequences (IS) contained in the genome, with 19 different types of ISs'. Upon oxidative stress these ISs' are actively transposed in the bacterium. Additionally, it carries at least 2 plasmids. Growth Characteristics ''Deniococcus geothermalis'' form tetrads when dividing. The size of their cells range from 1.2 - 2.0μm in diameter. It produces orange-pigmented colonies and has an optimum growth temperature of about to , which is the limit between mesophile and thermophile organisms. As well as having a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcus Deserti
''Deinococcus deserti'' is a Gram-negative, rod-shaped bacterium that belongs to the Deinococcaceae, a group of extremely radiotolerant bacteria. ''D. deserti'' and other Deinococcaceae exhibit an extraordinary ability to withstand ionizing radiation. Description ''Deinococcus deserti'' has in common with other ''Deinococci'' a highly condensed nucleoid, a high cellular Mn/Fe ratio, and several of the ''Deinococcus'' specific radiation tolerance-associated genes, for example, ddrA to ddrD, pprA, and irrE. The genome of ''D. deserti'' VCD115 is composed of four replicons: a main chromosome (2.82 Mb) and three plasmids, P1 (325 kb), P2 (314 kb) and P3 (396 kb). History Two gamma- and UV-radiation-tolerant strains were isolated from a mixture of sand samples collected in the Sahara Desert in Morocco and Tunisia, after exposure of the sand to 15 kGy gamma radiation. The strains did not grow on rich medium such as trypticase soy broth (TSB), but did grow as whitish colonies on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life
Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, metabolism, Cell growth, growth, adaptation, response to stimulus (physiology), stimuli, and reproduction. All life over time eventually reaches a state of death, and none is Immortality, immortal. Many philosophical definitions of living systems have been proposed, such as self-organizing systems. Viruses in particular make definition difficult as they replicate only in Host (biology), host cells. Life exists all over the Earth in air, water, and soil, with many ecosystems forming the biosphere. Some of these are harsh environments occupied only by extremophiles. Life has been studied since ancient times, with theories such as Empedocles's materialism asserting that it was composed of Classical element, four eternal elements, and Aristotle's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan cell wall sandwiched between an inner ( cytoplasmic) membrane and an outer membrane. These bacteria are found in all environments that support life on Earth. Within this category, notable species include the model organism '' Escherichia coli'', along with various pathogenic bacteria, such as '' Pseudomonas aeruginosa'', '' Chlamydia trachomatis'', and '' Yersinia pestis''. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and the antimicrobial enzyme lysozyme produced by animals as part of their innate immune system. Furthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, 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 the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and 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, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Space Station
The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United States), Roscosmos (Russia), European Space Agency, ESA (Europe), JAXA (Japan), and Canadian Space Agency, CSA (Canada). As the largest space station ever constructed, it primarily serves as a platform for conducting scientific experiments in microgravity and studying the space environment. The station is divided into two main sections: the Russian Orbital Segment (ROS), developed by Roscosmos, and the US Orbital Segment (USOS), built by NASA, ESA, JAXA, and CSA. A striking feature of the ISS is the Integrated Truss Structure, which connect the station’s vast system of solar panels and Spacecraft thermal control, radiators to its pressurized modules. These modules support diverse functions, including scientific research, crew habitation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panspermia
Panspermia () is the hypothesis that life exists throughout the universe, distributed by space dust, meteoroids, asteroids, comets, and planetoids, as well as by spacecraft carrying unintended contamination by microorganisms,Forward planetary contamination like '' Tersicoccus phoenicis'', that has shown resistance to methods usually used in spacecraft assembly clean rooms: known as directed panspermia. The theory argues that life did not originate on Earth, but instead evolved somewhere else and seeded life as we know it. Panspermia comes in many forms, such as radiopanspermia, lithopanspermia, and directed panspermia. Regardless of its form, the theories generally propose that microbes able to survive in outer space (such as certain types of bacteria or plant spores) can become trapped in debris ejected into space after collisions between planets and small solar system bodies that harbor life. This debris containing the lifeforms is then transported by meteors between bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is used by microbiologists to place bacteria into two main categories, gram-positive (+) and gram-negative bacteria, gram-negative (−). Gram-positive bacteria have a thick layer of peptidoglycan within the cell wall, and gram-negative bacteria have a thin layer of peptidoglycan. Gram-positive bacteria retain the crystal violet stain used in the test, resulting in a purple color when observed through an optical microscope. The thick layer of peptidoglycan in the bacterial cell wall retains the Stain (biology), stain after it has been fixed in place by iodine. During the decolorization step, the decolorizer removes crystal violet from all other cells. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofilm
A biofilm is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric combination of extracellular polysaccharides, proteins, lipids and DNA. Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living (biotic) or non-living (abiotic) surfaces and can be common in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiology, physiologically distinct from planktonic cells of the same organism, which, by contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
