Aphanizomenon ist eine Gattung der Cyanobacteria (früher „Blaualgen“ genannt). Typische Vertreter sind die Schlanke Wassernadel (A. gracile) und die Grüne Spanalge (oder Sichelalge der Karpfenteichwirtschaft) (A. flos-aquae).
Jeweils 20 bis 50 Zellen der Aphanizomenon-Arten bilden fadenförmige Kolonien, die sich ihrerseits büschelweise zusammenlagern, sodass makroskopisch sichtbare Aggregate entstehen. Diese schweben im Wasser und erzeugen den Eindruck etwa von Lärchennadeln. Insbesondere A. flos-aquae tritt in Form von Wasserblüten (Name!) massenhaft auf. Karpfenzüchter schätzen sie irrtümlich als Zeichen guter Fruchtbarkeit des betroffenen Teiches, dabei zeigt ihr Auftreten untrüglich eine einseitige Phosphat-Überdüngung an.
Aphanizomenon ist eine Gattung der Cyanobacteria (früher „Blaualgen“ genannt). Typische Vertreter sind die Schlanke Wassernadel (A. gracile) und die Grüne Spanalge (oder Sichelalge der Karpfenteichwirtschaft) (A. flos-aquae).
Jeweils 20 bis 50 Zellen der Aphanizomenon-Arten bilden fadenförmige Kolonien, die sich ihrerseits büschelweise zusammenlagern, sodass makroskopisch sichtbare Aggregate entstehen. Diese schweben im Wasser und erzeugen den Eindruck etwa von Lärchennadeln. Insbesondere A. flos-aquae tritt in Form von Wasserblüten (Name!) massenhaft auf. Karpfenzüchter schätzen sie irrtümlich als Zeichen guter Fruchtbarkeit des betroffenen Teiches, dabei zeigt ihr Auftreten untrüglich eine einseitige Phosphat-Überdüngung an.
Afanizomenon (Aphanizomenon Mogg) – ko‘k-yashil suvo‘tlar bo‘limining bir turkumi. Chuchuk suvlarda ko‘p uchraydi. O‘rta Osiyo suv havzalarida 4 ta turi bor. A. ba’zan suvning "gullashi"ga sa-bab bo‘ladi.
Afanizomenon (Aphanizomenon Mogg) – ko‘k-yashil suvo‘tlar bo‘limining bir turkumi. Chuchuk suvlarda ko‘p uchraydi. O‘rta Osiyo suv havzalarida 4 ta turi bor. A. ba’zan suvning "gullashi"ga sa-bab bo‘ladi.
Aphanizomenon is a genus of cyanobacteria that inhabits freshwater lakes and can cause dense blooms. They are unicellular organisms that consolidate into linear (non-branching) chains called trichomes. Parallel trichomes can then further unite into aggregates called rafts.[1] Cyanobacteria such as Aphanizomenon are known for using photosynthesis to create energy and therefore use sunlight as their energy source.[2] Aphanizomenon bacteria also play a big role in the Nitrogen cycle since they can perform nitrogen fixation. Studies on the species Aphanizomenon flos-aquae have shown that it can regulate buoyancy through light-induced changes in turgor pressure.[3] It is also able to move by means of gliding, though the specific mechanism by which this is possible is not yet known.
Aphanizomenon may become dominant in a water body partially due to their ability to induce phosphate-limitation in other phytoplankton while also increasing phosphate availability to itself through release of cylindrospermopsin.[4] The cylindrospermopsin causes other phytoplankton to increase their alkaline phosphatase activity, increasing inorganic phosphate availability in the water to Aphanizomenon during times when phosphate becomes limiting.
All species in the cyanobacteria phylum can perform photosynthesis. They use a similar photosynthesis to plants, using two photosystems which is called the Z-scheme. This is different from other photosynthetic bacteria that only use one photosystem and do not have thylakoids. Cyanobacteria species such as Aphanizomenon also use Oxygen as their final electron acceptor in the Electron Transport Chain, which is also different from other photosynthetic bacteria, which perform a type of photosynthesis called anoxygenic photosynthesis.[5]
Aphanizomenon are a special type of cyanobacteria called heterocysts, which are capable of producing biologically useful nitrogen (ammonium) by the process of nitrogen fixation from atmospheric nitrogen.
A large proportion (between 35 and 50%) of fixed nitrogen may be released into the surrounding water, providing an important source of biologically available nitrogen to the ecosystem.[6][7] Since Aphanizomenon are one of the few species of bacteria that can perform nitrogen fixation, other bacterial species that use nitrogen ions as a reactant will start to rely on the species as a source of usable nitrogen. This will cause a bacterial bloom to form, which is a condition under which the number of bacterial colonies in a area will suddenly increase.[8]
Aphanizomenon can produce algal blooms from producing usable nitrogen causing other bacterial species to form colonies around the Aphanizomenon. Algal Blooms formed from Aphanizomenon species tend to be very toxic and create a variety of toxins. These blooms may also create dead zones in the water. This ends up being bad for the ecosystem, since it can hurt many of the plants and animals living around it.[9]
Aphanizomenon species may produce cyanotoxins including cylindrospermospin (CYN), lipopolysaccharides (LPS), anatoxin-a, saxitoxin and BMAA.[10][11] Though not all Aphanizomenon produce cyanotoxins, many do. CYNs are a toxin that is especially toxic for the liver and kidney, thought to inhibit protein synthesis. LPSs are found in the cellular membrane of gram-negative bacterial cells and is released when the cellular membrane is degraded. The releasing of LPSs in animals can cause a severe immune response causing it to be very toxic for animals. Anatoxin-a is a type of anatoxin, it is normally released during algal blooms in lakes, causing exposure to animals around it. Anatoxin-a is toxic to the nerves in animals and is very lethal to humans with a lethal dose thought to be less than 5mg.[12] Similarly to anatoxin-a, BMAAs are another type of neurotoxin that lingers inside animals for longer than anatoxin-a. It will keep affecting animals even after a algal bloom dies down. Last, saxitoxins is yet another type of neurotoxin known to be released by a species of Aphanizomenon. It interrupts nerve transmissions to and from the brain, causing it to be very toxic.[13]
Aphanizomenon may form large colonies as a defense against herbivore grazing, especially Daphnia in freshwater. [14]
Guiry, M.D.; Guiry, G.M. "Aphanizomenon". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
Aphanizomenon is a genus of cyanobacteria that inhabits freshwater lakes and can cause dense blooms. They are unicellular organisms that consolidate into linear (non-branching) chains called trichomes. Parallel trichomes can then further unite into aggregates called rafts. Cyanobacteria such as Aphanizomenon are known for using photosynthesis to create energy and therefore use sunlight as their energy source. Aphanizomenon bacteria also play a big role in the Nitrogen cycle since they can perform nitrogen fixation. Studies on the species Aphanizomenon flos-aquae have shown that it can regulate buoyancy through light-induced changes in turgor pressure. It is also able to move by means of gliding, though the specific mechanism by which this is possible is not yet known.
Aphanizomenon on syanobakteerien suku, joka aiheuttaa leväkukintoja makeissa- ja murtovesissä.
Elävät Aphanizomenon-syanobakteerit ovat vihreitä, mutta kuollessaan ne muuttuvat turkoosinsinisiksi ja voivat muodostaa maalimaista massaa.[1][2]
Ne voidaan tunnistaa lajin ja suvun tarkkuudella mikroskoopin avulla. Aphanizomenon-suvulle ovat ominaisia sukkulamaiset rihmakimput. Rihmat koostuvat akineeteistä (kestosoluista) ja heterokysteistä (typensitojasoluista). Rihman solut eivät ole kuroutuneet helminauhamaisesti, vaan ne ovat tasaisemman jaokkeisia kuin Anabaena-rihmat.[3]
Aphanizomenon-levän kukinnat ovat yleisiä Itämeressä. Siellä siitä ei ole löydetty myrkyllisiä kantoja.[4] Ne voivat kuitenkin tuottaa myrkkyä järvissä. Joistakin aphanizomenon-levistä on löytynyt maksamyrkkyjä ja hermomyrkky anatoksiini-a:ta.[3]
Suvun tyyppilajia Aphanizomenon flosaquae on tavattu makeassa vedessä Euroopassa, Aasaissa, Pohjois- ja Etelä-Amerikassa, Australiassa ja Uudessa Seelannissa.[5]
Aphanizomenon on syanobakteerien suku, joka aiheuttaa leväkukintoja makeissa- ja murtovesissä.
Aphanizomenon est un genre de cyanobactéries de la famille des Aphanizomenonaceae.
Selon AlgaeBase (14 mai 2018)[1] :
Selon BioLib (14 mai 2018)[2] :
Selon Catalogue of Life (14 mai 2018)[4] et ITIS (14 mai 2018)[5] :
Selon World Register of Marine Species (14 mai 2018)[3] :
Aphanizomenon est un genre de cyanobactéries de la famille des Aphanizomenonaceae.
束絲藻屬（Aphanizomenon）隶属于蓝菌门念珠藻目念珠藻科，是一種在淡水生活的浮游丝状藻类，能引發水華[2][3]，但亦可調節水體的浮力[4]。
束絲藻屬並非所有品種均可食用，一來因為可能有毒[5]（例如纤细束丝藻和依沙束丝藻會产生麻痹性贝毒毒素[2]），二來可能因為水體本身就已污染，吃用了會連同污染物一起吃進肚裡。
束丝藻的特征是丝状体末端细胞渐细或成发状，延伸成无色的细胞[2]。可在水中透過滑翔來移動。
以下為常見之束丝藻品種[2]：
當中有研究透過比對16SrRNA和Rubisco两个基因，表明水华束丝藻和纤细束丝藻具有较高的亲缘关系,其相似性分别为 99%和99%,而依沙束丝藻亲缘关系较远,相似性分别只有96%和93-94%[2]。
