Cyanobacteria


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Cyanobacteria

 
the blue-green bacteria (formerly called blue-green algae), a subgroup of the kingdom Procaryotae, unicellular or filamentous phototrophic organisms that use water as an electron donor and produce oxygen in the presence of light. They are the only organisms that fix both carbon dioxide (in the presence of light) and nitrogen. Most species are photosynthetic and many are strong nitrogen fixers. Several species are common causes of water pollution and are often used as indicators of eutrophication of lakes and streams.

Cy·a·no·bac·te·ri·a

(sī'ă-nō-bak-tēr'ē-ă),
A division of the kingdom Prokaryotae consisting of unicellular or filamentous bacteria that are either nonmotile or possess a gliding motility, reproduce by binary fission, and perform photosynthesis with the production of oxygen. These blue-green bacteria were formerly referred to as blue-green algae.
Synonym(s): Cyanophyceae

Cyanobacteria

/Cy·a·no·bac·te·ria/ (si″ah-no-bak-tēr´e-ah) a subgroup of bacteria comprising the blue-green bacteria (blue-green algae), which are photosynthetic and also fix nitrogen.

cyanobacteria

[sī′ənōbaktir′ē·ə]
Etymology: Gk, kyanos, blue + bacterion, small staff
blue-green bacteria, unicellular or filamentous organisms that fix both carbon dioxide (in the presence of light) and nitrogen. Several species are common causes of water pollution and cause cyanobacteria poisoning. Formerly called blue-green algae.

Cy·a·no·bac·te·ri·a

(sī'ă-nō-bak-tēr'ē-ă)
A division of the kingdom Prokaryotae consisting of unicellular or filamentous bacteria that are either nonmotile or possess a gliding motility, reproduce by binary fission, and perform photosynthesis with the production of oxygen.
Synonym(s): Cyanophyceae.

cyanobacteria (formerly blue-green algae)

a PHYLUM within the DOMAIN BACTERIA (see CLASSIFICATION). Cyanobacteria are a group of photosynthetic PROKARYOTES capable of OXYGENIC PHOTOSYNTHESIS. Some are also capable of ANOXYGENIC PHOTOSYNTHESIS. They were formerly called blue-green algae mainly because of the colour of many species, caused by a blue pigment called phycocyanin. They may also contain a red pigment called phycoerythrin. All members contain chlorophyll a. However, Prochloron additionally contains chlorophyll b (see CHLOROPHYLL). The cyanobacteria were possibly the first ORGANISMS on the earth to produce OXYGEN by photosynthesis. There is fossil evidence for their occurrence 3.5 x 109 years ago. The CELL WALL is analogous to that of Gram-negative BACTERIA (see GRAM'S STAIN and the LIGHT REACTIONS of photosynthesis occur on the THYLAKOID MEMBRANE system, within the cell. Other structures in the cell include carboxysomes, polyphosphate bodies as a PHOSPHATE reserve, and gas VACUOLES for buoyancy Some cyanobacteria are UNICELLULAR, others are filamentous (see FILAMENT (2)). They reproduce by fission or fragmentation. A number of species shows CELLULAR DIFFERENTIATION, with the formation of, for example, AKINETES, and specialized cells for NITROGEN FIXATION, called heterocysts. Cyanobacteria are widespread, being found in both terrestrial and aquatic environments that are illuminated. Some live in very inhospitable environments such as hot springs, where the temperature is in excess of 85 °C. They are responsible for much of the photosynthetic oxygen evolution in oceans and contribute to productivity through CARBON DIOXIDE fixation (see DARK REACTIONS) and NITROGEN FIXATION. Sometimes they accumulate in large numbers as BLOOMS on the surface of lakes, reservoirs and so on. These blooms may produce TOXINS.

cyanobacteria

photosynthezing bacteria of widely varying form and inhabiting many environments including marine and fresh water. They produce a green pigment which changes color to blue or blue-green when the bacteria are stressed or dying. Formerly classified as algae (division Cyanophyta) and known as blue-green algae. Some species are non-toxic, some produce hepatoxins, others produce neurotoxins, and still others produce dermatoxins. Toxic species include Anabaena, Anabaenopsis, Aphanizomenon, Coelosphaerium, Cylindrospermopsis, Fischerella, Gloeotrichia, Gomphosphaeria, Haplosiphon, Hormothamnion, Lyngyba, Microcystis, Nodularia, Nostoc, Oscillatoria, Pseudoanabaena, Schizothrix, Seytonema, Synechococcus, Tolypothrix, Trichodesmium. Called also cyanophytes. See also algal poisoning.
References in periodicals archive ?
Biophotovoltaic cells contain some a type of cyanobacteria or algae that is phototrophic.
Recreational water exposure to excessive growths of cyanobacteria, called harmful algal blooms (HABs), can result in adverse health effects in humans and animals.
Isolation and identification of marine cyanobacteria: Cyanobacteria were isolated from samples of seawater, brackish water of the river mouth, and tissue of reef benthic invertebrates: the zoanthid Protopalythoa variabilis, the sponges Cinachyrella sp.
It appears the way cyanobacteria might be able to do this is by changing the structure of the phycobilisome complex in response to the environmental conditions.
A cyanobacteria trichome was considered as one organism; and in the case of diatoms and dinoflagellates, each cell was counted as one organism.
Picocyanophytes, a subgroup of Cyanobacteria, were examined separately from the Cyanobacteria group because they occurred at an order of magnitude higher than the other groups.
In order to isolate sea cyanobacteria, 500 ml of water has been transmitted through a filter with 45.
2]-fixation is mediated only by prokaryotic photoautotrophs including cyanobacteria and photosynthetic bacteria.
By growing cyanobacteria under chromium stress can help us to induce the expression of such thiols.
The project also includes a research component to improve understanding of the environmental causes and health impacts of cyanobacteria and phytoplankton blooms across the U.
Climate changes and eutrophication have provided ecological conditions for the development of cyanobacteria in a large number of Brazilian reservoirs.