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Cyanobacteria , also known as Cyanophyta, are a phylum of Gram-negative bacteria that obtain energy via photosynthesis. The name cyanobacteria comes from their color (Greek: , romanized: kyanós, lit. 'blue'), giving them their other name, "blue-green algae", though modern botanists restrict the term algae to eukaryotes and do not apply it to cyanobacteria, which are prokaryotes. They appear to have originated in freshwater or a terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria.
Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed.
Cyanobacteria produce a range of toxins known as cyanotoxins that can pose a danger to humans and animals.
The cyanobacteria Synechocystis and Cyanothece are important model organisms with potential applications in biotechnology for bioethanol production, food colorings, as a source of human and animal food, dietary supplements and raw materials.
Cyanobacteria are a group of photosynthetic bacteria, some of which are nitrogen-fixing, that live in a wide variety of moist soils and water either freely or in a symbiotic relationship with plants or lichen-forming fungi (as in the lichen genus Peltigera). They range from unicellular to filamentous and include colonial species. Colonies may form filaments, sheets, or even hollow spheres. Some filamentous species can differentiate into several different cell types: vegetative cells - the normal, photosynthetic cells that are formed under favorable growing conditions; akinetes - climate-resistant spores that may form when environmental conditions become harsh; and thick-walled heterocysts - which contain the enzyme nitrogenase, vital for nitrogen fixation in an anaerobic environment due to its sensitivity to oxygen.
Some cyanobacteria can fix atmospheric nitrogen in anaerobic conditions by means of specialized cells called heterocysts. Heterocysts may also form under the appropriate environmental conditions (anoxic) when fixed nitrogen is scarce. Heterocyst-forming species are specialized for nitrogen fixation and are able to fix nitrogen gas into ammonia , nitrites (NO− 2) or nitrates (NO− 3), which can be absorbed by plants and converted to protein and nucleic acids (atmospheric nitrogen is not bioavailable to plants, except for those having endosymbiotic nitrogen-fixing bacteria, especially the family Fabaceae, among
Free-living cyanobacteria are present in the water of rice paddies, and cyanobacteria can be found growing as epiphytes on the surfaces of the green alga, Chara, where they may fix nitrogen. Cyanobacteria such as Anabaena (a symbiont of the aquatic fern Azolla) can provide rice plantations with biofertilizer.
Many cyanobacteria form motile filaments of cells, called hormogonia, that travel away from the main biomass to bud and form new colonies elsewhere. The cells in a hormogonium are often thinner than in the vegetative state, and the cells on either end of the motile chain may be tapered. To break away from the parent colony, a hormogonium often must tear apart a weaker cell in a filament, called a necridium.
Each individual cell (each single cyanobacterium) typically has a thick, gelatinous cell wall. They lack flagella, but hormogonia of some species can move about by gliding along surfaces. Many of the multicellular filamentous forms of Oscillatoria are capable of a waving motion; the filament oscillates back and forth. In water columns, some cyanobacteria float by forming gas vesicles, as in archaea. These vesicles are not organelles as such. They are not bounded by lipid membranes but by a protein sheath.
Diagram of a typical cyanobacterial cell
Cyanobacteria have several unique features. As the endosymbiotic plastids are endosymbiotic cyanobacteria, they share these features insofar as they have not lost them.
Cyanobacteria use the energy of sunlight to drive photosynthesis, a process where the energy of light is used to synthesize organic compounds from carbon dioxide. Because they are aquatic organisms, they typically employ several strategies which are collectively known as a "CO2 concentrating mechanism" to aid in the acquisition of inorganic carbon ( or bicarbonate). Among the more specific strategies is the widespread prevalence of the bacterial microcompartments known as carboxysomes. These icosahedral structures are composed of hexameric shell proteins that assemble into cage-like structures that can be several hundreds of nanometers in diameter. It is believed that these structures tether the -fixing enzyme, RuBisCO, to the interior of the shell, as well as the enzyme carbonic anhydrase, using metabolic channeling to enhance the local concentrations and thus increase the efficiency of the RuBisCO enzyme.
While most of the high-energy electrons derived from water are used by the cyanobacterial cells for their own needs, a fraction of these electrons may be donated to the external environment via electrogenic activity.
Respiration in cyanobacteria can occur in the thylakoid membrane alongside photosynthesis, with their photosynthetic electron transport sharing the same compartment as the components of respiratory electron transport. While the goal of photosynthesis is to store energy by building carbohydrates from CO2, respiration is the reverse of this, with carbohydrates turned back into CO2 accompanying energy release.
Cyanobacteria appear to separate these two processes with their plasma membrane containing only components of the respiratory chain, while the thylakoid membrane hosts an interlinked respiratory and photosynthetic electron transport chain. Cyanobacteria use electrons from succinate dehydrogenase rather than from NADPH for respiration.
Cyanobacteria only respire during the night (or in the dark) because the facilities used for electron transport are used in reverse for photosynthesis while in the light.
Electron transport chain
Many cyanobacteria are able to reduce nitrogen and carbon dioxide under aerobic conditions, a fact that may be responsible for their evolutionary and ecological success. The water-oxidizing photosynthesis is accomplished by coupling the activity of photosystem (PS) II and I (Z-scheme). In contrast to green sulfur bacteria which only use one photosystem, the use of water as an electron donor is energetically demanding, requiring two photosystems.
Attached to the thylakoid membrane, phycobilisomes act as light-harvesting antennae for the photosystems. The phycobilisome components (phycobiliproteins) are responsible for the blue-green pigmentation of most cyanobacteria. The variations on this theme are due mainly to carotenoids and phycoerythrins that give the cells their red-brownish coloration. In some cyanobacteria, the color of light influences the composition of the phycobilisomes. In green light, the cells accumulate more phycoerythrin, whereas in red light they produce more phycocyanin. Thus, the bacteria appear green in red light and red in green light. This process of complementary chromatic adaptation is a way for the cells to maximize the use of available light for photosynthesis.
A few genera lack phycobilisomes and have chlorophyll b instead (Prochloron, Prochlorococcus, Prochlorothrix). These were originally grouped together as the prochlorophytes or chloroxybacteria, but appear to have developed in several different lines of cyanobacteria. For this reason, they are now considered as part of the cyanobacterial group.
The morphological similarity between chloroplasts and cyanobacteria was first reported by German botanist Andreas Franz Wilhelm Schimper in the 19th century Chloroplasts are only found in plants and algae, thus paving the way for Russian biologist Konstantin Mereschkowski to suggest the symbiogenic origin of the plastid in 1905.Lynn Margulis brought this hypothesis back to attention more than 60 years later but the idea did not become fully accepted until supplementary data started to accumulate. The cyanobacterial origin of plastids is now supported by various pieces of phylogenetic,genomic, biochemical and structural evidence. The description of another independent and more recent primary endosymbiosis event between a cyanobacterium and a separate eukaryote lineage (the rhizarianPaulinella chromatophora) also gives credibility to the endosymbiotic origin of the plastids.
Within this evolutionary context, it is noteworthy that, as far as we can tell, oxygenic photosynthesis only evolved once (in prokaryotic cyanobacteria), and all photosynthetic eukaryotes (including all plants and algae) have acquired this ability from them. In other words, all the oxygen that makes the atmosphere breathable for aerobic organisms originally comes from cyanobacteria or their later descendants.
Natural genetic transformation
Cyanobacteria are capable of natural genetic transformation. Natural genetic transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous DNA from its surroundings. For bacterial transformation to take place, the recipient bacteria must be in a state of competence, which may occur in nature as a response to conditions such as starvation, high cell density or exposure to DNA damaging agents. In chromosomal transformation, homologous transforming DNA can be integrated into the recipient genome by homologous recombination, and this process appears to be an adaptation for repairing DNA damage.
Environmental impact of cyanobacteria and other photosynthetic microorganisms in aquatic systems. Different classes of photosynthetic microorganisms are found in aquatic and marine environments where they form the base of healthy food webs and participate in symbioses with other organisms. However, shifting environmental conditions can result in community dysbiosis, where the growth of opportunistic species can lead to harmful blooms and toxin production with negative consequences to human health, livestock and fish stocks. Positive interactions are indicated by arrows; negative interactions are indicated by closed circles on the ecological model.
Aquatic cyanobacteria are known for their extensive and highly visible blooms that can form in both freshwater and marine environments. The blooms can have the appearance of blue-green paint or scum. These blooms can be toxic, and frequently lead to the closure of recreational waters when spotted. Marine bacteriophages are significant parasites of unicellular marine cyanobacteria.
Cyanobacterial growth is favored in ponds and lakes where waters are calm and have little turbulent mixing. Their life cycles are disrupted when the water naturally or artificially mixes from churning currents caused by the flowing water of streams or the churning water of fountains. For this reason blooms of cyanobacteria seldom occur in rivers unless the water is flowing slowly. Growth is also favored at higher temperatures which enable Microcystis species to outcompete diatoms and green algae, and potentially allow development of toxins.
Based on environmental trends, models and observations suggest cyanobacteria will likely increase their dominance in aquatic environments. This can lead to serious consequences, particularly the contamination of sources of drinking water. Researchers including Linda Lawton at Robert Gordon University, have developed techniques to study these. Cyanobacteria can interfere with water treatment in various ways, primarily by plugging filters (often large beds of sand and similar media) and by producing cyanotoxins, which have the potential to cause serious illness if consumed. Consequences may also lie within fisheries and waste management practices. Anthropogenic eutrophication, rising temperatures, vertical stratification and increased atmospheric carbon dioxide are contributors to cyanobacteria increasing dominance of aquatic ecosystems.
Cyanobacteria have been found to play an important role in terrestrial habitats. It has been widely reported that cyanobacteria soil crusts help to stabilize soil to prevent erosion and retain water. An example of a cyanobacterial species that does so is Microcoleus vaginatus. M. vaginatus stabilizes soil using a polysaccharide sheath that binds to sand particles and absorbs water.
"Cyanobacteria are arguably the most successful group of microorganisms on earth. They are the most genetically diverse; they occupy a broad range of habitats across all latitudes, widespread in freshwater, marine, and terrestrial ecosystems, and they are found in the most extreme niches such as hot springs, salt works, and hypersaline bays. Photoautotrophic, oxygen-producing cyanobacteria created the conditions in the planet's early atmosphere that directed the evolution of aerobic metabolism and eukaryotic photosynthesis. Cyanobacteria fulfill vital ecological functions in the world's oceans, being important contributors to global carbon and nitrogen budgets." - Stewart and Falconer
Collective behaviour and lifestyle choices in single-celled cyanobacteria 
Some cyanobacteria - even single-celled ones - show striking collective behaviours and form colonies (or blooms) that can float on water and have important ecological roles. For instance, billions of years ago, communities of marine Paleoproterozoic cyanobacteria could have helped create the biosphere as we know it by burying carbon compounds and allowing the initial build-up of oxygen in the atmosphere. On the other hand, toxic cyanobacterial blooms are an increasingly issue for society, as their toxins can be harmful to animals. Extreme blooms can also deplete water of oxygen and reduce sunlight and visibility, thereby compromising the feeding and mating behavior of light-reliant species.
As shown in the diagram on the right, bacteria can stay in suspension as individual cells, adhere collectively to surfaces to form biofilms, passively sediment, or flocculate to form suspended aggregates. Cyanobacteria are able to produce sulphated polysaccharides (yellow haze surrounding clumps of cells) that enable them to form floating aggregates. In 2021, Maeda et al. discovered that oxygen produced by cyanobacteria becomes trapped in the network of polysaccharides and cells, enabling the microorganisms to form buoyant blooms. It is thought specific protein fibres known as pili (represented as lines radiating from the cells) may act as an additional way to link cells to each other or onto surfaces. Some cyanobacteria also use sophisticated intracellular gas vesicles as floating aids.
The diagram on the left shows a proposed model of microbial distribution, spatial organization, carbon and O2 cycling in clumps and adjacent areas. (a) Clumps contain denser cyanobacterial filaments and heterotrophic microbes. The initial differences in density depend on cyanobacterial motility and can be established over short timescales. Darker blue color outside of the clump indicates higher oxygen concentrations in areas adjacent to clumps. Oxic media increase the reversal frequencies of any filaments that begin to leave the clumps, thereby reducing the net migration away from the clump. This enables the persistence of the initial clumps over short timescales; (b) Spatial coupling between photosynthesis and respiration in clumps. Oxygen produced by cyanobacteria diffuses into the overlying medium or is used for aerobic respiration. Dissolved inorganic carbon (DIC) diffuses into the clump from the overlying medium and is also produced within the clump by respiration. In oxic solutions, high O2 concentrations reduce the efficiency of CO2 fixation and result in the excretion of glycolate. Under these conditions, clumping can be beneficial to cyanobacteria if it stimulates the retention of carbon and the assimilation of inorganic carbon by cyanobacteria within clumps. This effect appears to promote the accumulation of particulate organic carbon (cells, sheaths and heterotrophic organisms) in clumps.
It has been unclear why and how cyanobacteria form communities. Aggregation must divert resources away from the core business of making more cyanobacteria, as it generally involves the production of copious quantities of extracellular material. In addition, cells in the centre of dense aggregates can also suffer from both shading and shortage of nutrients. So, what advantage does this communal life bring for cyanobacteria?
New insights into how cyanobacteria form blooms have come from a 2021 study on the cyanobacterium Synechocystis. These use a set of genes that regulate the production and export of sulphated polysaccharides, chains of sugar molecules modified with sulphate groups that can often be found in marine algae and animal tissue. Many bacteria generate extracellular polysaccharides, but sulphated ones have only been seen in cyanobacteria. In Synechocystis these sulphated polysaccharide help the cyanobacterium form buoyant aggregates by trapping oxygen bubbles in the slimy web of cells and polysaccharides.
Previous studies on Synechocystis have shown type IV pili, which decorate the surface of cyanobacteria, also play a role in forming blooms. These retractable and adhesive protein fibres are important for motility, adhesion to substrates and DNA uptake. The formation of blooms may require both type IV pili and Synechan - for example, the pili may help to export the polysaccharide outside the cell. Indeed, the activity of these protein fibres may be connected to the production of extracellular polysaccharides in filamentous cyanobacteria. A more obvious answer would be that pili help to build the aggregates by binding the cells with each other or with the extracellular polysaccharide. As with other kinds of bacteria, certain components of the pili may allow cyanobacteria from the same species to recognise each other and make initial contacts, which are then stabilised by building a mass of extracellular polysaccharide.
The bubble flotation mechanism identified by Maeda et al. joins a range of known strategies that enable cyanobacteria to control their buoyancy, such as using gas vesicles or accumulating carbohydrate ballasts. Type IV pili on their own could also control the position of marine cyanobacteria in the water column by regulating viscous drag. Extracellular polysaccharide appears to be a multipurpose asset for cyanobacteria, from floatation device to food storage, defence mechanism and mobility aid.
Timing and trends in cell diameter, loss of filamentous forms and habitat preference within cyanobacteria
Taxa are not drawn to scale - those with smaller cell diameters are at the bottom and larger at the top
Cyanobacteria have fundamentally transformed the geochemistry of the planet. Multiple lines of geochemical evidence support the occurrence of intervals of profound global environmental change at the beginning and end of the Proterozoic (2,500-542 Mya). While it is widely accepted that the presence of molecular oxygen in the early fossil record was the result of cyanobacteria activity, little is known about how cyanobacteria evolution (e.g., habitat preference) may have contributed to changes in biogeochemical cycles through Earth history. Geochemical evidence has indicated that there was a first step-increase in the oxygenation of the Earth's surface, which is known as the Great Oxidation Event (GOE), in the early Paleoproterozoic (2,500-1,600 Mya). A second but much steeper increase in oxygen levels, known as the Neoproterozoic Oxygenation Event (NOE), occurred at around 800 to 500 Mya. Recent chromium isotope data point to low levels of atmospheric oxygen in the Earth's surface during the mid-Proterozoic, which is consistent with the late evolution of marine planktonic cyanobacteria during the Cryogenian; both types of evidence help explain the late emergence and diversification of animals.
Understanding the evolution of planktonic cyanobacteria is important because their origin fundamentally transformed the nitrogen and carbon cycles towards the end of the Pre-Cambrian. It remains unclear, however, what evolutionary events led to the emergence of open-ocean planktonic forms within cyanobacteria and how these events relate to geochemical evidence during the Pre-Cambrian. So far, it seems that ocean geochemistry (e.g., euxinic conditions during the early- to mid-Proterozoic) and nutrient availability  likely contributed to the apparent delay in diversification and widespread colonization of open ocean environments by planktonic cyanobacteria during the Neoproterozoic.
Marine phytoplankton today contribute to almost half of the Earth's total primary production. Within the cyanobacteria, only a few lineages colonized the open-ocean (i.e., Crocosphaera and relatives, cyanobacterium UCYN-A, Trichodesmium, as well as Prochlorococcus and Synechococcus). From these lineages, nitrogen fixing cyanobacteria are particularly important because they exert a control on primary productivity and the export of organic carbon to the deep ocean, by converting nitrogen gas into ammonium, which is later used to make amino acids and proteins. Marine picocyanobacteria (i.e., Prochlorococcus and Synechococcus) numerically dominate most phytoplankton assemblages in modern oceans contributing importantly to primary productivity. While some planktonic cyanobacteria are unicellular and free living cells (e.g., Crocosphaera, Prochlorococcus, Synechococcus), others have established symbiotic relationships with prymnesiophyte algae. Amongst the filamentous forms, Trichodesmium are free-living and form aggregates. However, filamentous heterocyst-forming cyanobacteria (e.g., Richelia, Calothrix) are found in association with diatoms such as Hemiaulus, Rhizosolenia and Chaetoceros.
During the Precambrian, stromatolite communities of microorganisms grew in most marine and non-marine environments in the photic zone. After the Cambrian explosion of marine animals, grazing on the stromatolite mats by herbivores greatly reduced the occurrence of the stromatolites in marine environments. Since then, they are found mostly in hypersaline conditions where grazing invertebrates cannot live (e.g. Shark Bay, Western Australia). Stromatolites provide ancient records of life on Earth by fossil remains which date from 3.5 Ga ago. As of 2010[update] the oldest undisputed evidence of cyanobacteria is from 2.1 Ga ago, but there is some evidence for them as far back as 2.7 Ga ago. Oxygen concentrations in the atmosphere remained around or below 1% of today's level until 2.4 Ga ago (the Great Oxygenation Event). The rise in oxygen may have caused a fall in the concentration of atmospheric methane, and triggered the Huronian glaciation from around 2.4 to 2.1 Ga ago. In this way, cyanobacteria may have killed off much of the other bacteria of the time.
Oncolites are sedimentary structures composed of oncoids, which are layered structures formed by cyanobacterial growth. Oncolites are similar to stromatolites, but instead of forming columns, they form approximately spherical structures that were not attached to the underlying substrate as they formed. The oncoids often form around a central nucleus, such as a shell fragment, and a calcium carbonate structure is deposited by encrusting microbes. Oncolites are indicators of warm waters in the photic zone, but are also known in contemporary freshwater environments. These structures rarely exceed 10 cm in diameter.
One former classification scheme of cyanobacterial fossils divided them into the porostromata and the spongiostromata. These are now recognized as form taxa and considered taxonomically obsolete; however, some authors have advocated for the terms remaining informally to describe form and structure of bacterial fossils.
Oncolitic limestone formed from successive layers of calcium carbonate precipitated by cyanobacteria
Cyanobacterial remains of an annulated tubular microfossilOscillatoriopsis longa Scale bar: 100 ?m
Tree of Life in Generelle Morphologie der Organismen (1866). Note the location of the genus Nostoc with algae and not with bacteria (kingdom "Monera")
Historically, bacteria were first classified as plants constituting the class Schizomycetes, which along with the Schizophyceae (blue-green algae/Cyanobacteria) formed the phylum Schizophyta, then in the phylum Monera in the kingdom Protista by Haeckel in 1866, comprising Protogens, Protamaeba, Vampyrella, Protomonae, and Vibrio, but not Nostoc and other cyanobacteria, which were classified with algae,
later reclassified as the Prokaryotes by Chatton.
The members of Chroococales are unicellular and usually aggregate in colonies. The classic taxonomic criterion has been the cell morphology and the plane of cell division. In Pleurocapsales, the cells have the ability to form internal spores (baeocytes). The rest of the sections include filamentous species. In Oscillatoriales, the cells are uniseriately arranged and do not form specialized cells (akinetes and heterocysts). In Nostocales and Stigonematales, the cells have the ability to develop heterocysts in certain conditions. Stigonematales, unlike Nostocales, include species with truly branched trichomes.
Most taxa included in the phylum or division Cyanobacteria have not yet been validly published under The International Code of Nomenclature of Prokaryotes (ICNP) except:
Cyanobacteria cultured in specific media: Cyanobacteria can be helpful in agriculture as they have the ability to fix atmospheric nitrogen in soil.
Researchers from a company called Algenol have cultured genetically modified cyanobacteria in sea water inside a clear plastic enclosure so they first make sugar (pyruvate) from and the water via photosynthesis. Then, the bacteria secrete ethanol from the cell into the salt water. As the day progresses, and the solar radiation intensifies, ethanol concentrations build up and the ethanol itself evaporates onto the roof of the enclosure. As the sun recedes, evaporated ethanol and water condense into droplets, which run along the plastic walls and into ethanol collectors, from where it is extracted from the enclosure with the water and ethanol separated outside the enclosure. As of March 2013, Algenol was claiming to have tested its technology in Florida and to have achieved yields of 9,000 US gallons per acre per year. This could potentially meet US demands for ethanol in gasoline in 2025, assuming a B30 blend, from an area of around half the size of California's San Bernardino County, requiring less than one-tenth of the area than ethanol from other biomass, such as corn, and only very limited amounts of fresh water.
Cyanobacteria may possess the ability to produce substances that could one day serve as anti-inflammatory agents and combat bacterial infections in humans. Cyanobacteria's photosynthetic output of sugar and oxygen has been demonstrated to have therapeutic value in rats with heart attacks. While cyanobacteria can naturally produce various secondary metabolites, they can serve as advantageous hosts for plant-derived metabolites production owing to biotechnological advances in systems biology and synthetic biology.
Spirulina's extracted blue color is used as a natural food coloring.
Researchers from several space agencies argue that cyanobacteria could be used for producing goods for human consumption in future manned outposts on Mars, by transforming materials available on this planet.
Some microalgae contain substances of high biological value, such as polyunsaturated fatty acids, amino acids, proteins, pigments, antioxidants, vitamins, and minerals. Edible blue-green algae reduce the production of pro-inflammatory cytokines by inhibiting NF-?B pathway in macrophages and splenocytes. Sulfate polysaccharides exhibit immunomodulatory, antitumor, antithrombotic, anticoagulant, anti-mutagenic, anti-inflammatory, antimicrobial, and even antiviral activity against HIV, herpes, and hepatitis.
Recent studies suggest that significant exposure to high levels of cyanobacteria producing toxins such as BMAA can cause amyotrophic lateral sclerosis (ALS). People living within half a mile of cyanobacterially contaminated lakes have had a 2.3 times greater risk of developing ALS than the rest of the population; people around New Hampshire's Lake Mascoma had an up to 25 times greater risk of ALS than the expected incidence. BMAA from desert crusts found throughout Qatar might have contributed to higher rates of ALS in Gulf War veterans.
Several chemicals can eliminate cyanobacterial blooms from smaller water-based systems such as swimming pools. They include calcium hypochlorite, copper sulphate, cupricide, and simazine. The calcium hypochlorite amount needed varies depending on the cyanobacteria bloom, and treatment is needed periodically. According to the Department of Agriculture Australia, a rate of 12 g of 70% material in 1000 l of water is often effective to treat a bloom. Copper sulfate is also used commonly, but no longer recommended by the Australian Department of Agriculture, as it kills livestock, crustaceans, and fish. Cupricide is a chelated copper product that eliminates blooms with lower toxicity risks than copper sulfate. Dosage recommendations vary from 190 ml to 4.8 l per 1000 m2. Ferric alum treatments at the rate of 50 mg/l will reduce algae blooms. Simazine, which is also a herbicide, will continue to kill blooms for several days after an application. Simazine is marketed at different strengths (25, 50, and 90%), the recommended amount needed for one cubic meter of water per product is 25% product 8 ml; 50% product 4 ml; or 90% product 2.2 ml.
Climate change favours cyanobacterial blooms both directly and indirectly. Many bloom-forming cyanobacteria can grow at relatively high temperatures. Increased thermal stratification of lakes and reservoirs enables buoyant cyanobacteria to float upwards and form dense surface blooms, which gives them better access to light and hence a selective advantage over nonbuoyant phytoplankton organisms. Protracted droughts during summer increase water residence times in reservoirs, rivers and estuaries, and these stagnant warm waters can provide ideal conditions for cyanobacterial bloom development.
The capacity of the harmful cyanobacterial genus Microcystis to adapt to elevated CO2 levels was demonstrated in both laboratory and field experiments.Microcystis spp. take up CO2 and HCO3- and accumulate inorganic carbon in carboxysomes, and strain competitiveness was found to depend on the concentration of inorganic carbon. As a result, climate change and increased CO2 levels are expected to affect the strain composition of cyanobacterial blooms.
^Liberton M, Pakrasi HB (2008). "Chapter 10. Membrane Systems in Cyanobacteria". In Herrero A, Flore E (eds.). The Cyanobacteria: Molecular Biology, Genomics, and Evolution. Norwich, United Kingdom: Horizon Scientific Press. pp. 217-87. ISBN978-1-904455-15-8.
^ abKhayatan, Behzad; Meeks, John C.; Risser, Douglas D. (2015). "Evidence that a modified type IV pilus-like system powers gliding motility and polysaccharide secretion in filamentous cyanobacteria". Molecular Microbiology. 98 (6): 1021-1036. doi:10.1111/mmi.13205. PMID26331359. S2CID8749419.
^Fralick, Philip; Davis, Don W.; Kissin, Stephen A. (2002). "The age of the Gunflint Formation, Ontario, Canada: Single zircon UPb age determinations from reworked volcanic ash". Canadian Journal of Earth Sciences. 39 (7): 1085-1091. Bibcode:2002CaJES..39.1085F. doi:10.1139/e02-028. C1 control character in |title= at position 68 (help)
^Castellani, Christopher; Maas, Andreas; Eriksson, Mats E.; Haug, Joachim T.; Haug, Carolin; Waloszek, Dieter (2018). "First record of Cyanobacteria in Cambrian Orsten deposits of Sweden". Palaeontology. 61 (6): 855-880. doi:10.1111/pala.12374.
^Von Nägeli C (1857). Caspary R (ed.). "Bericht über die Verhandlungen der 33. Versammlung deutscher Naturforscher und Ärzte, gehalten in Bonn von 18 bis 24 September 1857" [Report on the Proceedings of the 33rd Meeting of German Natural Scientists and Physicians, held in Bonn, 18 to 24 September 1857]. Botanische Zeitung. 15: 749-76.
^Tabei Y, Okada K, Tsuzuki M (April 2007). "Sll1330 controls the expression of glycolytic genes in Synechocystis sp. PCC 6803". Biochemical and Biophysical Research Communications. 355 (4): 1045-50. doi:10.1016/j.bbrc.2007.02.065. PMID17331473.
^Rocap G, Larimer FW, Lamerdin J, Malfatti S, Chain P, Ahlgren NA, Arellano A, Coleman M, Hauser L, Hess WR, Johnson ZI, Land M, Lindell D, Post AF, Regala W, Shah M, Shaw SL, Steglich C, Sullivan MB, Ting CS, Tolonen A, Webb EA, Zinser ER, Chisholm SW (August 2003). "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation". Nature. 424 (6952): 1042-47. Bibcode:2003Natur.424.1042R. doi:10.1038/nature01947. PMID12917642. S2CID4344597.
^Caller TA, Doolin JW, Haney JF, Murby AJ, West KG, Farrar HE, Ball A, Harris BT, Stommel EW (2009). "A cluster of amyotrophic lateral sclerosis in New Hampshire: a possible role for toxic cyanobacteria blooms". Amyotrophic Lateral Sclerosis. 10 Suppl 2: 101-08. doi:10.3109/17482960903278485. PMID19929741. S2CID35250897.
^Cox PA, Richer R, Metcalf JS, Banack SA, Codd GA, Bradley WG (2009). "Cyanobacteria and BMAA exposure from desert dust: a possible link to sporadic ALS among Gulf War veterans". Amyotrophic Lateral Sclerosis. 10 Suppl 2: 109-17. doi:10.3109/17482960903286066. PMID19929742. S2CID1748627.
^Cox, Paul Alan; Brand, Larry E.; Murch, Susan J.; Tymm, Fiona J. M.; Powell, James T.; Banack, Sandra Anne; Metcalf, James S. (2018). "Public health responses to toxic cyanobacterial blooms: Perspectives from the 2016 Florida event". Water Policy. 20 (5): 919-932. doi:10.2166/wp.2018.012.
^Visser, Petra M.; Verspagen, Jolanda M.H.; Sandrini, Giovanni; Stal, Lucas J.; Matthijs, Hans C.P.; Davis, Timothy W.; Paerl, Hans W.; Huisman, Jef (2016). "How rising CO2 and global warming may stimulate harmful cyanobacterial blooms". Harmful Algae. 54: 145-159. doi:10.1016/j.hal.2015.12.006. PMID28073473.
^Walsby, Anthony E.; Hayes, Paul K.; Boje, Rolf; Stal, Lucas J. (1997). "The selective advantage of buoyancy provided by gas vesicles for planktonic cyanobacteria in the Baltic Sea". New Phytologist. 136 (3): 407-417. doi:10.1046/j.1469-8137.1997.00754.x. PMID33863010.
^Lehman, P.W.; Kurobe, T.; Lesmeister, S.; Baxa, D.; Tung, A.; Teh, S.J. (2017). "Impacts of the 2014 severe drought on the Microcystis bloom in San Francisco Estuary". Harmful Algae. 63: 94-108. doi:10.1016/j.hal.2017.01.011. PMID28366405.