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Acidobacteria is a phylum of bacteria. Its members are physiologically diverse and ubiquitous, especially in soils, but are under-represented in culture.
Verrucomicrobia is a phylum of bacteria that contains only a few described species. The species identified have been isolated from fresh water, marine and soil environments and human faeces. A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes.
Pelagibacter, with the single species P. ubique, was isolated in 2002 and given a specific name, although it has not yet been described as required by the bacteriological code. It is an abundant member of the SAR11 clade in the phylum Alphaproteobacteria. SAR11 members are highly dominant organisms found in both salt and fresh water worldwide – possibly the most numerous bacterium in the world, and were originally known only from their rRNA genes, which were first identified in environmental samples from the Sargasso Sea in 1990 by Stephen Giovannoni's laboratory in the Department of Microbiology at Oregon State University and later found in oceans worldwide. P. ubique and its relatives may be the most abundant organisms in the ocean, and quite possibly the most abundant bacteria in the entire world. It can make up about 25% of all microbial plankton cells, and in the summer they may account for approximately half the cells present in temperate ocean surface water. The total abundance of P. ubique and relatives is estimated to be about 2 × 1028 microbes.
An exopolymer is a biopolymer that is secreted by an organism into the environment. These exopolymers include the biofilms produced by bacteria to anchor them and protect them from environmental conditions. One type of expolymer, Transparent Exopolymers (TEP), found in both marine and aquatic ecosystems, are planktonic acidic polysaccharides of a gel-like consistency, originally defined by their ability to be stained visible by acidic Alcian Blue. Their free-floating characteristic sets TEPs aside from other extracellular polymeric substance subgroups where exopolymers exists as cell coating, dissolved slime or as part of biofilm matrices.
Alphaproteobacteria is a class of bacteria in the phylum Proteobacteria. Its members are highly diverse and possess few commonalities, but nevertheless share a common ancestor. Like all Proteobacteria, its members are gram-negative and some of its intracellular parasitic members lack peptidoglycan and are consequently gram variable.
The PVC group is a superphylum of bacteria named after its three important members, Planctomycetes, Verrucomicrobia, and Chlamydiae. Cavalier-Smith postulated that the PVC bacteria probably lost or reduced their peptidoglycan cell wall twice. It has been hypothesised that a member of the PVC clade might have been the host cell in the endosymbiotic event that gave rise to the first proto-eukaryotic cell.
The Chloroflexi or Chlorobacteria are a phylum of bacteria containing isolates with a diversity of phenotypes, including members that are aerobic thermophiles, which use oxygen and grow well in high temperatures; anoxygenic phototrophs, which use light for photosynthesis ; and anaerobic halorespirers, which uses halogenated organics as electron acceptors.
The Pelagibacterales are an order in the Alphaproteobacteria composed of free-living marine bacteria that make up roughly one in three cells at the ocean's surface. Overall, members of the Pelagibacterales are estimated to make up between a quarter and a half of all prokaryotic cells in the ocean.
Lentisphaerae is a phylum of bacteria closely related to Chlamydiae and Verrucomicrobia.
Bacterial phyla constitute the major lineages of the domain Bacteria. While the exact definition of a bacterial phylum is debated, a popular definition is that a bacterial phylum is a monophyletic lineage of bacteria whose 16S rRNA genes share a pairwise sequence identity of ~75% or less with those of the members of other bacterial phyla.
Acanthopleuribacter is a genus in the phylum Acidobacteria (bacteria).
Cucumibacter is a genus in the phylum Proteobacteria (Bacteria).
Croceitalea is a genus in the phylum Bacteroidetes (Bacteria).
Croceibacter is a genus in the phylum Bacteroidetes (Bacteria).
Erythrobacter litoralis is a species of bacterium. E. litoralis strain HTCC2594 was first sequenced in 2009. Erythrobacter litoralis strain DSM 8509 was developed as a comparative genetic model system to investigate the role of visible light in regulation of the general stress response in Alphaproteobacteria. The complete genome sequence of E. litoralis DSM 8509 has been published.
Weissella thailandensis is a species of Gram-positive bacteria. It is a homofermentative, sphere-shaped lactic acid bacteria. Its type strain is FS61-1T. Its genome has been sequenced.
Victivallis vadensis is a Gram-negative, coccus-shaped, bacteria found in the human digestive tract. It measures approximately 0.5-1.3 micrometers in diameter, is non-motile and chemoorganotrophic, and does not form spores. Victivallis vadensis is strictly anaerobic, as are 90 percent of the bacteria in the human gastrointestinal system.
Magnetococcus marinus is a species of Alphaproteobacteria that has the peculiar ability to form a structure called a magnetosome, a membrane-encased, single-magnetic-domain mineral crystal formed by biomineralisation, which allows the cells to orient along the Earth’s geomagnetic field.
Transparent exopolymer particles (TEPs) are extracellular acidic polysaccharides produced by phytoplankton and bacteria in saltwater, freshwater, and wastewater. They are incredibly abundant and play a significant role in biogeochemical cycling of carbon and other elements in water. Through this, they also play a role in the structure of food webs and trophic levels. TEP production and overall concentration has been observed to be higher in the Pacific Ocean compared to the Atlantic, and is more related to solar radiation in the Pacific. TEP concentration has been found to decrease with depth, having the highest concentration at the surface, especially associated with the SML, either by upward flux or sea surface production. Chlorophyll a has been found to be the best indicator of TEP concentration, rather than heterotrophic grazing abundance, further emphasizing the role of phytoplankton in TEP production. TEP concentration is especially enhanced by haptophyte phytoplanktonic dominance, solar radiation exposure, and close proximity to sea ice. TEPs also do not seem to show any diel cycles. High concentrations of TEPs in the surface ocean slow the sinking of solid particle aggregations, prolonging pelagic residence time. TEPs may provide an upward flux of materials such as bacteria, phytoplankton, carbon, and trace nutrients. High TEP concentrations were found under arctic sea ice, probably released by sympagic algae. TEP is efficiently recycled in the ocean, as heterotrophic grazers such as zooplankton and protists consume TEP and produce new TEP precursors to be reused, further emphasizing the importance of TEPs in marine carbon cycling. TEP abundance tends to be higher in coastal, shallow waters compared to deeper, oceanic waters. Diatom-dominated phytoplankton colonies produce larger, and stickier, TEPs, which may indicate that TEP size distribution and composition may be a useful tool in determining aggregate planktonic community structure.
References
- ↑ Parte, A.C. "Lentisphaera". LPSN .
- ↑ Cho, J. C.; Vergin, K. L.; Morris, R. M.; Giovannoni, S. J. (2004). "Lentisphaera araneosa gen. Nov., sp. Nov, a transparent exopolymer producing marine bacterium, and the description of a novel bacterial phylum, Lentisphaerae". Environmental Microbiology. 6 (6): 611–621. doi:10.1111/j.1462-2920.2004.00614.x. PMID 15142250.
- ↑ Choi, Ahyoung; Yang, Seung-Jo; Rhee, Kwang-Hyun; Cho, Jang-Cheon (April 2013). "Lentisphaera marina sp. nov., and emended description of the genus Lentisphaera". International Journal of Systematic and Evolutionary Microbiology. 63 (4): 1540–1544. doi:10.1099/ijs.0.046433-0. PMID 22888188.
- ↑ Thrash, J. Cameron; Cho, Jang-Cheon; Vergin, Kevin L.; Morris, Robert M.; Giovannoni, Stephen J. (June 2010). "Genome Sequence of Lentispheara araneosa HTCC2155T, the Type Species of the Order Lentisphaerales in the Phylum Lentisphaerae". Journal of Bacteriology. 192 (11): 2938–2939. doi:10.1128/JB.00208-10. PMC 2876483 . PMID 20363947.
