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Green Sulfur Bacteria
The green sulfur bacteria are a phylum, Chlorobiota, of obligately anaerobic photoautotrophic bacteria that metabolize sulfur. Green sulfur bacteria are nonmotile (except ''Chloroherpeton thalassium'', which may glide) and capable of anoxygenic photosynthesis. They live in anaerobic aquatic environments. In contrast to plants, green sulfur bacteria mainly use sulfide ions as electron donors. They are autotrophs that utilize the reverse tricarboxylic acid cycle to perform carbon fixation. They are also mixotrophs and reduce nitrogen. Characteristics Green sulfur bacteria are gram-negative rod or spherical shaped bacteria. Some types of green sulfur bacteria have gas vacuoles that allow for movement. They are photolithoautotrophs, and use light energy and reduced sulfur compounds as the electron source. Electron donors include , , S. The major photosynthetic pigment in these bacteria is Bacteriochlorophylls ''c'' or ''d'' in green species and ''e'' in brown species, and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winogradsky Column
{{Short description, Device for culturing microorganisms The Winogradsky column is a simple device for culturing a large diversity of microorganisms. Invented in the 1880s by Sergei Winogradsky, the device is a column of pond mud and water mixed with a carbon source such as newspaper (containing cellulose), blackened marshmallows or egg-shells (containing calcium carbonate), and a sulfur source such as gypsum ( calcium sulfate) or egg yolk. Incubating the column in sunlight for months results in an aerobic/ anaerobic gradient as well as a sulfide gradient. These two gradients promote the growth of different microorganisms such as '' Clostridium'', '' Desulfovibrio'', '' Chlorobium'', ''Chromatium'', '' Rhodomicrobium'', and '' Beggiatoa'', as well as many other species of bacteria, cyanobacteria, and algae. The column provides numerous gradients, depending on additive nutrients, from which the variety of aforementioned organisms can grow. The aerobic water phase and anaerobic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemocline
A chemocline is a type of cline, a layer of fluid with different properties, characterized by a strong, vertical chemistry gradient within a body of water. In bodies of water where chemoclines occur, the cline separates the upper and lower layers, resulting in different properties for those layers. The lower layer shows a change in the concentration of dissolved gases and solids compared to the upper layer. Chemoclines most commonly occur where local conditions favor the formation of anoxic bottom water — deep water deficient in oxygen, where only anaerobic forms of life can exist. Common anaerobic organisms that live in these conditions include phototrophic purple sulfur bacteria and green sulfur bacteria. The Black Sea is an example of a body of water with a prominent chemocline, though similar bodies (classified as meromictic lakes) exist across the globe. Meromictic lakes are the result of meromixis, which is a circumstance where a body of water does not fully mix and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorobium Limicola
''Chlorobium limicola'' is a gram negative bacterial member of green sulfur bacteria genus found in freshwater hot springs. ''C. limicola'' is a non-motile mesophile A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum growth range from . The optimum growth temperature for these organisms is 37 °C (about 99 °F). The term is mainly applied ..., photoautotrophic / photosynthetic strict anaerobe important to carbon, nitrogen and sulfur cycles in anoxic freshwater environments. Strain DSMZ 245 T was isolated from Gilroy Hot Springs in California, and whole genome sequencing was accomplished. Believed to be morphologically diverse, it was determined that culturing techniques determine some characteristics like slime production and morphology. As a green sulfur bacteria, ''C. limicola'' fixes carbon via reverse TCA cycle reactions. Genetics Whole genome sequencing was accomplished on Strain DSMZ 245 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosthecochloris Aestuarii
''Prosthecochloris aestuarii'' is a green sulfur bacterium in the genus '' Prosthecochloris''. This organism was originally isolated from brackish lagoons located in Sasyk-Sivash and Sivash. They are characterized by the presence of "prosthecae" on their cell surface; the inner part of these appendages house the photosynthetic machinery within chlorosomes, which are characteristic structures of green sulfur bacteria. Additionally, like other green sulfur bacteria, they are Gram-negative, non-motile, and non-spore forming. Of the four major groups of green sulfur bacteria, ''P. aestuarii'' serves as the type species for Group 4. Cell morphology ''P. aestuarii'' are noted to have a more ellipsoidal shape, but may appear spherical after cell division. Additionally, they can range between 0.5 and 0.7 microns in width and between 1.0 and 1.2 microns in length, and individual cells can produce up to 20 of the prosthecae appendages. These prosthecae can extend an additional 0.1 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome Taxonomy Database
The Genome Taxonomy Database (GTDB) is an online database that maintains information on a proposed nomenclature of prokaryotes, following a phylogenomic approach based on a set of conserved single-copy proteins. In addition to resolving paraphyletic groups, this method also reassigns taxonomic ranks algorithmically, updating names in both cases. Information for archaea was added in 2020, along with a species classification based on average nucleotide identity. Each update incorporates new genomes as well as automated and manual curation of the taxonomy. An open-source tool called GTDB-Tk is available to classify draft genomes into the GTDB hierarchy. The GTDB system, via GTDB-Tk, has been used to catalogue not-yet-named bacteria in the human gut microbiome and other metagenomic sources. The GTDB is incorporated into the '' Bergey's Manual of Systematics of Archaea and Bacteria'' in 2019 as its phylogenomic resource. Methodology The genomes used to construct the phyloge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The All-Species Living Tree Project
The All-Species Living Tree' Project is a collaboration between various academic groups/institutes, such as ARB, SILVA rRNA database project, and LPSN, with the aim of assembling a database of 16S rRNA sequences of all validly published species of ''Bacteria'' and ''Archaea''. At one stage, 23S sequences were also collected, but this has since stopped. Currently there are over 10,950 species in the aligned dataset and several more are being added either as new species are discovered or species that are not represented in the database are sequenced. Initially the latter group consisted of 7% of species. Similar (and more recent) projects include the Genomic Encyclopedia of Bacteria and Archaea (GEBA), which focused on whole genome sequencing of bacteria and archaea. Tree The tree was created by maximum likelihood analysis without bootstrap: consequently accuracy is traded off for size and many phylum level clades are not correctly resolved (such as the Firmicutes). (Eukaryote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermophile
A thermophile is a type of extremophile that thrives at relatively high temperatures, between . Many thermophiles are archaea, though some of them are bacteria and fungi. Thermophilic eubacteria are suggested to have been among the earliest bacteria. Thermophiles are found in geothermally heated regions of the Earth, such as hot springs like those in Yellowstone National Park and deep sea hydrothermal vents, as well as decaying plant matter, such as peat bogs and compost. They can survive at high temperatures, whereas other bacteria or archaea would be damaged and sometimes killed if exposed to the same temperatures. The enzymes in thermophiles function at high temperatures. Some of these enzymes are used in molecular biology, for example the ''Taq'' polymerase used in PCR. "Thermophile" is derived from the (''thermotita''), meaning heat, and (''philia''), love. Comparative surveys suggest that thermophile diversity is principally driven by pH, not temperature. Classificat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorobaculum Tepidum
''Chlorobaculum tepidum'', previously known as ''Chlorobium tepidum'', is an anaerobic, thermophilic green sulfur bacteria first isolated from New Zealand. Its cells are gram-negative and non-motile rods of variable length. They contain chlorosomes and bacteriochlorophyll a and c. Natural habitat and environmental requirements Like other green sulfur bacteria ''C. tepidum'' requires light and specific compounds to perform anoxygenic photosynthesis. ''C. tepidum'' differs from other green sulfur bacteria in that it cannot easily use H2 or Fe2+ as electron donors, relying on elemental sulfur, sulfide, and thiosulfate instead. To fulfill their metabolic requirements, they reside primarily in anaerobic sulfur rich environments such as anaerobic levels of Stratification (water), stratified lakes and lagoons, anaerobic levels of layered organic bacterial mats, and in hot springs where there is abundant sulfur. ''C. tepidum'' and other green sulfur bacteria also play a large role wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
