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Endospore-forming Bacteria
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., not an offspring). It is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in Gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. There are many reports of spores remaining viable over 10,000 years, and revival of spores millions of years old has been claimed. There is one report of viable spores of '' Bacillus marismortui'' in salt crystals approximately 25 million years old. When the environment becomes more favorable, the endospore can reactivate itself into a vegetative state. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus Subtilis Spore
''Bacillus'', from Latin "bacillus", meaning "little staff, wand", is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum ''Bacillota'', with 266 named species. The term is also used to describe bacillus (shape), the shape (rod) of other so-shaped bacteria; and the plural ''Bacilli'' is the name of the class (biology), class of bacteria to which this genus belongs. ''Bacillus'' species can be either obligate aerobes which are dependent on oxygen, or facultative anaerobes which can survive in the absence of oxygen. Cultured ''Bacillus'' species test positive for the enzyme catalase if oxygen has been used or is present. ''Bacillus'' can reduce themselves to oval endospores and can remain in this dormant state for years. The endospore of one species from Morocco is reported to have survived being heated to 420 °C. Endospore formation is usually triggered by a lack of nutrients: the bacterium divides within its cell wall, and one side then engulfs the other. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipicolinic Acid
Dipicolinic acid (pyridine-2,6-dicarboxylic acid or PDC and DPA) is a chemical compound which plays a role in the heat resistance of bacterial endospores. It is also used to prepare and transition metal complexes for ion chromatography.2,6-Pyridinedicarboxylic acid at Biological role Dipicolinic acid composes 5% to 15% of the dry weight of '''' spores. It has been implicated as responsible for the heat resistance of the |
Sieve
A sieve (), fine mesh strainer, or sift is a tool used for separating wanted elements from unwanted material or for controlling the particle size distribution of a sample, using a screen such as a woven mesh or net or perforated sheet material. The word ''sift'' derives from ''sieve''. In cooking, a sifter is used to separate and break up clumps in dry ingredients such as flour, as well as to aerate and combine them. A strainer (see colander), meanwhile, is a form of sieve used to separate suspended solids from a liquid by filtration. Sieving Sieving is a simple technique for separating particles of different sizes. A sieve such as used for sifting flour has very small holes. Coarse particles are separated or broken up by grinding against one another and the screen openings. Depending upon the types of particles to be separated, sieves with different types of holes are used. Sieves are also used to separate stones from sand. Sieving plays an important role in food ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exosporium
The exosporium is the outer surface layer of mature spores. In plant spores it is also referred to as the exine. Some bacteria also produce endospores with an exosporium, of which the most commonly studied are ''Bacillus'' species, particularly ''Bacillus cereus'' and the anthrax-causing bacterium ''Bacillus anthracis''. The exosporium is the portion of the spore that interacts with the environment or host organism, and may contain spore antigens. Exosporium proteins, such as Cot protein, are also discovered related to strains of B. anthracis and B.cereus. This Cot protein share similar sequences with other spore coat proteins, and their putative determinants are believed to include bxpC, lunA, exsA, etc. In ''Bacillus anthracis'', salt and detergent washing of exosporium fragments can identify proteins that are likely to represent structural or integral exosporium proteins. Seven proteins have been identified in washed exosporium: alanine racemase, inosine hydrolase, ExsF, CotY, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetative Cells
Vegetative describes vegetation. Vegetative may also refer to: *Vegetative reproduction, a type of asexual reproduction for plants *Persistent vegetative state, a condition of people with severe brain damage *Plant community A plant community is a collection or Association (ecology), association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The comp ..., sometimes called a vegetative community, a collection of plants in a geographic area * Vegetative (or somatic) cell, a non-reproductive cell {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptobiotic
Cryptobiosis or anabiosis is a metabolic state in extremophilic organisms in response to adverse environmental conditions such as desiccation, freezing, and oxygen Hypoxia (medical), deficiency. In the cryptobiotic state, all measurable metabolic processes stop, preventing reproduction, development, and repair. When environmental conditions return to being hospitable, the organism will return to its metabolism, metabolic state of life as it was prior to cryptobiosis. Forms Anhydrobiosis Anhydrobiosis is the most studied form of cryptobiosis and occurs in situations of extreme desiccation. The term ''anhydrobiosis'' derives from the Greek for "life without water" and is most commonly used for the desiccation tolerance observed in certain invertebrate animals such as Bdelloidea, bdelloid rotifers, tardigrades, brine shrimp, nematodes, and at least one insect, a species of chironomid (''Polypedilum vanderplanki''). However, other life forms exhibit desiccation tolerance. Thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endospore Formation
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., not an offspring). It is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in Gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. There are many reports of spores remaining viable over 10,000 years, and revival of spores millions of years old has been claimed. There is one report of viable spores of '' Bacillus marismortui'' in salt crystals approximately 25 million years old. When the environment becomes more favorable, the endospore can reactivate itself into a vegetative state. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbial Cyst
A microbial cyst is a resting or dormant stage of a microorganism, that can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed and the cell ceases all activities like feeding and locomotion. Many groups of single-celled, microscopic organisms, or microbes, possess the ability to enter this dormant state. Encystment, the process of cyst formation, can function as a method for dispersal and as a way for an organism to survive in unfavorable environmental conditions. These two functions can be combined when a microbe needs to be able to survive harsh conditions between habitable environments (such as between hosts) in order to disperse. Cysts can also be sites for nuclear reorganization and cell division, and in parasitic species they are often the infectious stage between hosts. When the encysted microbe reaches an environment favorable to its growth and survival, the cyst wall breaks down by a process known as excystation. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steinn Sigurdsson
Steinn may refer to: * Andri Steinn (born 1979), Icelandic film editor * Guðmundur Steinn Gunnarsson (born 1982), Icelandic composer * Hallar-Steinn, Icelandic poet active around the year 1200 * Snorri Steinn Gudjonsson (born 1981), Icelandic handball player * Steinn O. Thompson (1893–1972), politician in Manitoba, Canada *Steinn Steinarr (1908–1958), Icelandic poet * Kári Steinn Karlsson (born 1986), Icelandic long-distance runner * Hjörvar Steinn Grétarsson (born 1993), Icelandic chess player See also * Völu-Steinn, Icelandic skald of the mid-10th century *Stein (other) Stein may refer to: Places Austria * Stein, a neighbourhood of Krems an der Donau, Lower Austria * Stein, Styria, a municipality in the district of Fürstenfeld, Styria * Stein (Lassing), a village in the district of Liezen, Styria * Stein an d ... * Steina * Steine (other) * Steinnes {{given name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferdinand Cohn
Ferdinand Julius Cohn (24 January 1828 – 25 June 1898) was a German biologist. He is one of the founders of modern bacteriology and microbiology. Biography Ferdinand Julius Cohn was born in the Jewish quarter of Breslau in the Prussian Province of Silesia (modern-day Wrocław, Poland). His father, Issak Cohn, was a successful merchant and manufacturer who for some time held the post of Austro-Hungarian consul. He was the elder brother of humorist and playwright Oskar Justinus Cohn and of historian and jurist . He was considered a child prodigy, and could read at the age of two. He also suffered hearing impairment from a young age. He entered the in 1835 at the age or 6 or 7, and the University of Breslau in 1842 or 1844. There he studied botany under Heinrich Göppert and Christian Nees von Esenbeck. Cohn was refused admission to the University of Breslau's doctoral program because of his Jewish background. He thus continued his studies at the University of Berlin, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
