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Clostridium Bifermentans
''Paraclostridium bifermentans'', formerly known as ''Clostridium bifermentans'' and abbreviated CLOBI, is an anaerobic, motile, gram-positive bacterium. Toxins and mosquito larvae A certain subspecies, ''Clostridium bifermentans'' subsp. Malaysia, was the first anaerobic bacterium known to kill mosquito larvae. The subspecies was part of a collection at the Institute for Medical Research, Malaysia. A biochemical analysis found that the mosquitocidal cry toxin is coded by four genes in an operon: cry16Aa, cry17Aa, cbm17.1, and cbm17.2. When the four genes were individually expressed, none of the four proteins encoded exhibited mosquitocidal activity. This suggests that the toxicity requires four proteins cooperating as a complex to take effect. A single promoter was found upstream of the four genes, indicating that the four were likely to be expressed simultaneously. The half-life of toxicity was about one day and the toxin was unstable in high temperature. Although ''C. biferment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deutsche Sammlung Von Mikroorganismen Und Zellkulturen
The Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH (German: ''Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH''), located in Braunschweig, is a research infrastructure in the Leibniz Association. Also the DSMZ is the world's most diverse collection of bioresources (status 2021: 75,000 bioresources). These include microorganisms (including more than 32,000 bacterial strains, 690 archaeal strains, 7,000 strains of yeasts and fungi) as well as more than 840 human and animal cell cultures, over 1. 500 plant viruses, over 940 bacteriophages, and 250 plasmids (status 2021). Since 2010, the scientific director of the Leibniz Institute DSMZ has been Jörg Overmann, a microbiologist with a PhD. He holds a professorship in microbiology at the Technical University of Braunschweig. Since August 2018, he has led the institute in a dual leadership with Bettina Fischer as administrative director. History Structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organism
An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. Deep waters of the ocean are a common anoxic environment. First observation In his letter of 14 June 1680 to The Royal Society, Antonie van Leeuwenhoek described an experiment he carried out by filling two identical glass tubes about halfway with crushed pepper powder, to which some clean rain water was added. Van Leeuwenhoek sealed one of the glass tubes using a flame an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motility
Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms that do not possess a means of self-locomotion and are normally immobile. Motility differs from mobility, the ability of an object to be moved. The term vagility encompasses both motility and mobility; sessile organisms including plants and fungi often have vagile parts such as fruits, seeds, or spores which may be dispersed by other agents such as wind, water, or other organisms. Motility is genetically determined, but may be affected by environmental factors such as toxins. The nervous system and musculoskeletal system provide the majority of mammalian motility. In addition to animal locomotion, most animals are motile, though some are vagile, described as having passive locomotion. Many bacteria and other microorganisms, and multicellu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacterium
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. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (safra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cry Toxin
Delta endotoxins (δ-endotoxins) are pore-forming toxins produced by '' Bacillus thuringiensis'' species of bacteria. They are useful for their insecticidal action and are the primary toxin produced by Bt maize/corn. During spore formation the bacteria produce crystals of such proteins (hence the name Cry toxins) that are also known as parasporal bodies, next to the endospores; as a result some members are known as a parasporin. The Cyt (cytolytic) toxin group is a group of delta-endotoxins different from the Cry group. Mechanism of action When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. For many years there was no clarity as to the relationship between aminopeptidase N and Bt toxins. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operon
In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be ''co-transcribed'' to define an operon. Originally, operons were thought to exist solely in prokaryotes (which includes organelles like plastids that are derived from bacteria), but since the discovery of the first operons in eukaryotes in the early 1990s, more evidence has arisen to suggest they are more common than previously assumed. In general, expression of prokaryotic operons leads to the generation of polycistronic mRNAs, while eukaryotic operons lead to monocistronic mRNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anopheles
''Anopheles'' () is a genus of mosquito first described and named by J. W. Meigen in 1818. About 460 species are recognised; while over 100 can transmit human malaria, only 30–40 commonly transmit parasites of the genus ''Plasmodium'', which cause malaria in humans in endemic areas. '' Anopheles gambiae'' is one of the best known, because of its predominant role in the transmission of the most dangerous malaria parasite species (to humans) – '' Plasmodium falciparum''. The name comes from the Ancient Greek word 'useless', derived from , 'not', 'un-' and 'profit'. Mosquitoes in other genera (''Aedes'', ''Culex'', '' Culiseta'', '' Haemagogus'', and ''Ochlerotatus'') can also serve as vectors of disease agents, but not human malaria. Evolution The ancestors of ''Drosophila'' and the mosquitoes diverged . The culicine and ''Anopheles'' clades of mosquitoes diverged between and . The Old and New World ''Anopheles'' species subsequently diverged between and . '' Anophel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aedes
''Aedes'' is a genus of mosquitoes originally found in tropical and subtropical zones, but now found on all continents except perhaps Antarctica. Some species have been spread by human activity: ''Aedes albopictus'', a particularly invasive species, was spread to the New World, including the United States, in the 1980s, by the used-tire trade. First described and named by German entomologist Johann Wilhelm Meigen in 1818, the generic name comes from the Ancient Greek ἀηδής, ''aēdēs'', meaning "unpleasant" or "odious". The type species for ''Aedes'' is ''Aedes cinereus''.. Systematics and phylogeny The genus was named by Johann Wilhelm Meigen in 1818. The generic name comes from the Ancient Greek ἀηδής, ''aēdēs'', meaning "unpleasant" or "odious". As historically defined, the genus contains over 700 species (see the list of ''Aedes'' species). The genus has been divided into several subgenera (''Aedes'', '' Diceromyia'', '' Finlaya'', ''Stegomyia'', etc.) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BacDive
Bac''Dive'' (the Bacterial Diversity Metadatabase) is a bacterial metadatabase that provides strain-linked information about bacterial and archaeal biodiversity. Introduction Bac''Dive'' is a resource for different kind of metadata like taxonomy, morphology, physiology, environment and molecular-biology. The majority of data is manually annotated and curated. With the release in July 2018 Bac''Dive'' offers information for 63,669 strains. The database is hosted by the Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH and is part ode.NBIthe German Network for Bioinformatics Infrastructure. Content and Features Database The July 2018 release of the database encompassed over 600 different data fields, divided into the categories "Name and taxonomic classification", "Morphology and physiology", "Culture and growth conditions," "Isolation, sampling and environmental information." "Application and interaction", "Molecular biology" and "Strain av ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
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. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria Described In 1918
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large 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, 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 fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of 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 sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationships wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
