Anabaena
Filamentous cyanobacteria fixing nitrogen and producing neurotoxins.
Anabaena is a genus of filamentous cyanobacteria that exist as plankton. They are known for nitrogen-fixing abilities and form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to local wildlife, farm animals, and pets.
- field
- Cyanobacteria
- known_for
- Nitrogen fixation, neurotoxin production, symbiotic relationships with plants
- neurotoxin_producers
- One of four genera of cyanobacteria that produce neurotoxins
Lore & Background
The study focused on heterocysts, which convert nitrogen into ammonia. Certain species of Anabaena have been used on rice paddy fields, proving to be an effective natural fertilizer. The genus has significant overlap with Aphanizomenon. Despite An. The group around Trichormus variabilis is better-supported by data than grouping it together with main-group Anabaena/Aphanizomenon, so it is more likely for the two species to be split out.
Reader's Guide
Anabaena is significant as a model organism for studying nitrogen fixation, simple vision, and DNA repair. Under nitrogen-limiting conditions, vegetative cells differentiate into heterocysts at semiregular intervals along the filaments. Heterocyst cells are terminally specialized for nitrogen fixation, with a micro-oxic interior due to increased respiration, inactivation of O2-producing photosystem II, and formation of a thickened envelope. Nitrogenase within these cells transforms dinitrogen into ammonia. The fern Azolla forms a symbiotic relationship with Anabaena azollae, which fixes atmospheric nitrogen, allowing the plant to double its biomass in as little as 1.9 days. Anabaena is also used as a model organism to study simple vision, specifically through Anabaena sensory rhodopsin, a light-sensitive membrane protein. A study of RecN protein dynamics in DSB repair in Anabaena indicated differential regulation of DSB repair, active in vegetative cells but absent in mature heterocysts. Many sequenced morphospecies in the ADA clade are not monophyletic, and work is underway to sequence more genomes for a classification based on genetic branching.
Did You Know?
- Anabaena is one of four genera of cyanobacteria that produce neurotoxins.
- Anabaena azollae is completely dependent on its host Azolla, as several of its genes are either lost or transferred to the nucleus in Azolla's cells.
- Anabaena is used as a model organism to study simple vision via Anabaena sensory rhodopsin.
Frequently Asked Questions
Who is Anabaena?
Anabaena is a genus of filamentous cyanobacteria that drifts through water as plankton. It belongs to the cyanobacteria field and is recognized for its dual nature as both a nitrogen fixer and a neurotoxin producer.
What are Anabaena's powers and role?
Anabaena can fix atmospheric nitrogen into usable forms and produces neurotoxins that harm local wildlife, farm animals, and pets. It is one of only four cyanobacteria genera known to generate these neurotoxic compounds.
How does Anabaena's story end?
As a persistent planktonic organism, Anabaena does not have a narrative ending in the traditional sense—it cycles through blooms and dormancy in aquatic ecosystems indefinitely. Its ongoing ecological presence means it remains a constant factor in the water bodies it inhabits.
Why is Anabaena important?
Anabaena plays a critical role in aquatic nitrogen cycling and forms beneficial symbiotic partnerships with plants like the mosquito fern. At the same time, its neurotoxin production makes it a significant concern for ecosystem health and animal safety.
Who does Anabaena partner with?
Anabaena establishes symbiotic relationships with certain plants, most notably the mosquito fern, where it provides fixed nitrogen in exchange for a stable habitat. This mutualistic arrangement is one of its most ecologically significant interactions.
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