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Michael Krings - One of the best experts on this subject based on the ideXlab platform.
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a coccoid colony forming cyanobacterium from the lower devonian rhynie chert that resembles eucapsis synechococcales and entophysalis Chroococcales
Review of Palaeobotany and Palynology, 2019Co-Authors: Michael Krings, Vladimir N SergeevAbstract:Abstract The Rhynie chert provides sublime fossils of cyanobacteria from an Early Devonian hot spring ecosystem. However, only a small fraction of the diversity has been documented. Rhyniotaxillus devonicus nov. gen. et sp., a minute coccoid cyanobacterium from the Rhynie chert, is characterized by cuboid to somewhat irregular colonies of up to 64 cells (cell diameter: 2.5–3.5 μm) arranged into sarcinoid packages, and held together by prominent gelatinous envelopes. Colony morphology parallels that seen in certain present-day species of Eucapsis (Synechococcales) and Entophysalis (Chroococcales), as well as Eoentophysalis belcherensis , a Precambrian fossil equivalent of Entophysalis . The systematic affinities of R. devonicus remain unresolved. Nevertheless, this discovery expands our knowledge of cyanobacterial diversity in early non-marine ecosystems.
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a colony forming microorganism with probable affinities to the Chroococcales cyanobacteria from the lower devonian rhynie chert
Review of Palaeobotany and Palynology, 2015Co-Authors: Thomas N Taylor, Michael KringsAbstract:The Rhynie chert has provided a wealth of information on Early Devonian non-marine aquatic and terrestrial life. However, our understanding of the microbial biodiversity in this hot spring paleoecosystem remains incomplete. In this paper we describe Rhyniosarcina devonica nov. gen. et sp., a microorganism from the Rhynie chert that forms cubical, spheroidal, or irregular colonies of up to several hundred densely packed cells (< 2.5–5.5 μm in diameter). Square groups of four cells and sarcinoid packages of eight cells represent the basic modular units in the construction of the colonies. Cell division is by binary fission in three planes in space; new colonies form by colony dissociation. Rhyniosarcina devonica is interpreted as a cyanobacterium with affinities to the Chroococcales based on morphological similarities to extant colony-forming chroococcalean cyanobacteria, especially members in the genus Cyanosarcina. This discovery expands our knowledge of the diversity of primary producers in the Rhynie chert.
Hans Utkilen - One of the best experts on this subject based on the ideXlab platform.
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Energy state and toxin content – experiments on Microcystis aeruginosa (Chroococcales, Cyanophyta)
Phycologia, 2020Co-Authors: Heike Bickel, Susanne Lyck, Hans UtkilenAbstract:Abstract The correlation between the ratio of microcystin to protein and the energy state of Microcystis aeruginosa NIVA-CYA 228/1 (Chroococcales, Cyanophyta) was examined at three levels of phosphorus and iron in continuous cultures. Phosphorus- and iron-depleted conditions resulted in an increased transparency of the cultures, and together this caused significant changes in adenylate energy charge (EC) and microcystin content of M. aeruginosa. The EC ranged between 0.47 and 0.63. The microcystin content of the cells increased from 3 to 23 ng microcystin μg−1 protein in phosphorus-depleted cultures and from 2 to 12 ng microcystin μg−1 protein in iron-depleted cultures. A positive correlation between EC and microcystin content of the cells in both phosphorus- and iron-depleted cultures indicates that factors that affect EC influence microcystin production. Phosphorus and iron depletion modulated the cellular composition of M. aeruginosa. Carbohydrate constituted 5–8% of dry weight when the organisms were ...
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energy state and toxin content experiments on microcystis aeruginosa Chroococcales cyanophyta
Phycologia, 2000Co-Authors: Heike Bickel, Susanne Lyck, Hans UtkilenAbstract:Abstract The correlation between the ratio of microcystin to protein and the energy state of Microcystis aeruginosa NIVA-CYA 228/1 (Chroococcales, Cyanophyta) was examined at three levels of phosphorus and iron in continuous cultures. Phosphorus- and iron-depleted conditions resulted in an increased transparency of the cultures, and together this caused significant changes in adenylate energy charge (EC) and microcystin content of M. aeruginosa. The EC ranged between 0.47 and 0.63. The microcystin content of the cells increased from 3 to 23 ng microcystin μg−1 protein in phosphorus-depleted cultures and from 2 to 12 ng microcystin μg−1 protein in iron-depleted cultures. A positive correlation between EC and microcystin content of the cells in both phosphorus- and iron-depleted cultures indicates that factors that affect EC influence microcystin production. Phosphorus and iron depletion modulated the cellular composition of M. aeruginosa. Carbohydrate constituted 5–8% of dry weight when the organisms were ...
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iron starvation increases toxicity of microcystis aeruginosa cya 228 1 Chroococcales cyanophyceae
Phycologia, 1996Co-Authors: Susanne Lyck, Nina Gjolme, Hans UtkilenAbstract:Abstract Toxin production and growth during iron starvation was studied in the toxic strain Microcystis aeruginosa (Kutzing) Lemmermann CYA 228/1 and the non-toxic strain M. aeruginosa CYA 143, using continuous culture. Iron starvation resulted in a 5-fold decrease in chlorophyll a content and a 3-fold decrease in the protein content in both organisms while a minor increase in dry weight was observed. The toxicity measured as the ratio of toxin to chlorophyll or toxin to protein was found to increase during iron starvation. During iron-depletion, the toxic strain of Microcystis maintained its cell vitality much longer than the non-toxic strain.
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Iron starvation increases toxicity of Microcystis aeruginosa CYA 228/1 (Chroococcales, Cyanophyceae)
Phycologia, 1996Co-Authors: Susanne Lyck, Nina Gjolme, Hans UtkilenAbstract:Abstract Toxin production and growth during iron starvation was studied in the toxic strain Microcystis aeruginosa (Kutzing) Lemmermann CYA 228/1 and the non-toxic strain M. aeruginosa CYA 143, using continuous culture. Iron starvation resulted in a 5-fold decrease in chlorophyll a content and a 3-fold decrease in the protein content in both organisms while a minor increase in dry weight was observed. The toxicity measured as the ratio of toxin to chlorophyll or toxin to protein was found to increase during iron starvation. During iron-depletion, the toxic strain of Microcystis maintained its cell vitality much longer than the non-toxic strain.
Celia Leite Santanna - One of the best experts on this subject based on the ideXlab platform.
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occurrence of the rare genus microcrocis p richter Chroococcales cyanobacteria in a coastal lagoon from southern brazil
Brazilian Journal of Botany, 2006Co-Authors: Vera Regina Werner, Celia Leite SantannaAbstract:The paper records the first occurrence of the genus Microcrocis P. Richter (Chroococcales, Cyanobacteria), represented by M. pulchella (Buell) Geitler, in Brazil. The species was found in two zones, one with freshwater and the other with brackish water, of a coastal lagoon of Rio Grande do Sul State (31°15-31°30 S and 50°54-51°09 W). Comparison between M. pulchella and its most closely related species is presented. Up to now this species had occurrence records limited to freshwater systems in temperate regions. Its presence in a subtropical coastal lagoon from southernmost Brazil, either in fresh or in brackish water, broadened the knowledge of the distribution area of M. pulchella.
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planktic cyanobacteria from sao paulo state brazil Chroococcales
Brazilian Journal of Botany, 2004Co-Authors: Celia Leite Santanna, Jirí Komárek, Maria Teresa De P Azevedo, Pedro Americo Cabral Senna, Jaroslava KomarkovaAbstract:Estudos de biodiversidade de cianobacterias planctonicas iniciaram-se em 1997 com intenso esquema de coletas em diferentes corpos d'agua do Estado de Sao Paulo. Em virtude dos problemas gerados pela eutrofizacao e pelas frequentes floracoes de cianobacterias, as amostragens foram concentradas em reservatorios da regiao do Alto Tiete que fornecem agua para milhoes de pessoas. As amostras foram coletadas com rede de plâncton de 20 µm de abertura de malha ou com Garrafa de Van Dorn. Parte de cada amostra foi preservada com formol ou lugol e parte foi isolada e mantida em cultura em meios BG11 e/ou AMS1. Com base no estudo de material de campo e de cultura, 26 especies foram identificadas, pertencentes as familias Chroococcaceae (2 taxons), Merismopediaceae (12), Microcystaceae (7) e Synechococcaceae (5). Dentre estas especies, seis sao potencialmente toxicas: Aphanocapsa incerta (Lemmerm.) Cronberg & Komarek, Microcystis aeruginosa (Kutz.) Kutz., M. botrys Teiling, M. panniformis Komarek et al., M. wesenbergii (Komarek) Komarek, e Radiocystis fernandoi Komarek & Komar.-Legn. Bacularia e Coelosphaeriopsis sao generos citados pela primeira vez para o Brasil.
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two common microcystis species Chroococcales cyanobacteria from tropical america including m panniformis sp nov
Cryptogamie Algologie, 2002Co-Authors: Jirí Komárek, Celia Leite Santanna, Maria Teresa De P Azevedo, Jaroslava Komarkovalegnerova, Pedro Americo Cabral SennaAbstract:Deux especes de Microcystis communes en Amerique tropicale. Certaines populations tropicales de cyanophytes planctoniques d'eau douce du genre Microcystis ressemblent morphologiquement a des especes des regions temperees mais en different par des caracteres phenotypiques subtils mais stables et souvent par leurs cycles biologiques. Les variations morphologiques, les cycles vitaux et la structure cellulaire ont ete etudies a la fois dans des cultures et des populations naturelles de deux especes communement distribuees dans les regions tropicales et subtropicales de l'est et du sud-est du Bresil. Elles ont ete alternativement nommees « Microcystis aeruginosa », « M. flos-aquae » ou « M. cf. lamelliformis » dans la litterature floristique ou hydrobiologique, mais elles representent clairement des morphotypes differents en fonction de la morphologie des colonies et des cycles vitaux. Une de ces especes correspond phenotypiquement au M. protocystis originellement decrit du Sri Lanka par Crow en 1923 et oublie depuis lors tandis que la seconde est decrite ici comme M. panniformis sp. nov. Toutes deux appartiennent a un groupe d'especes, probablement pantropicales et toxiques, formant des fleurs d'eau.
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validation of the name stichosiphon mangle Chroococcales cyanophyta
Taxon, 1995Co-Authors: Luis Henrique Zanini Branco, Simone Maria F Silva, Celia Leite SantannaAbstract:Stichosiphon mangle Branco & al. (1994: 2) was proposed on the basis of material gathered in mangroves on Cardoso Island (Brazil) and Inhaca Island (Mozambique). The authors designated figures 1-19 of the protologue as the type. This designation of figures, however, is not permitted by Art. 8.3 of the Tokyo Code, because preserved collections exist. Moreover, the figures were of material from both Brazil and Mozambique and do not, therefore, represent a single element.
Susanne Lyck - One of the best experts on this subject based on the ideXlab platform.
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Energy state and toxin content – experiments on Microcystis aeruginosa (Chroococcales, Cyanophyta)
Phycologia, 2020Co-Authors: Heike Bickel, Susanne Lyck, Hans UtkilenAbstract:Abstract The correlation between the ratio of microcystin to protein and the energy state of Microcystis aeruginosa NIVA-CYA 228/1 (Chroococcales, Cyanophyta) was examined at three levels of phosphorus and iron in continuous cultures. Phosphorus- and iron-depleted conditions resulted in an increased transparency of the cultures, and together this caused significant changes in adenylate energy charge (EC) and microcystin content of M. aeruginosa. The EC ranged between 0.47 and 0.63. The microcystin content of the cells increased from 3 to 23 ng microcystin μg−1 protein in phosphorus-depleted cultures and from 2 to 12 ng microcystin μg−1 protein in iron-depleted cultures. A positive correlation between EC and microcystin content of the cells in both phosphorus- and iron-depleted cultures indicates that factors that affect EC influence microcystin production. Phosphorus and iron depletion modulated the cellular composition of M. aeruginosa. Carbohydrate constituted 5–8% of dry weight when the organisms were ...
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energy state and toxin content experiments on microcystis aeruginosa Chroococcales cyanophyta
Phycologia, 2000Co-Authors: Heike Bickel, Susanne Lyck, Hans UtkilenAbstract:Abstract The correlation between the ratio of microcystin to protein and the energy state of Microcystis aeruginosa NIVA-CYA 228/1 (Chroococcales, Cyanophyta) was examined at three levels of phosphorus and iron in continuous cultures. Phosphorus- and iron-depleted conditions resulted in an increased transparency of the cultures, and together this caused significant changes in adenylate energy charge (EC) and microcystin content of M. aeruginosa. The EC ranged between 0.47 and 0.63. The microcystin content of the cells increased from 3 to 23 ng microcystin μg−1 protein in phosphorus-depleted cultures and from 2 to 12 ng microcystin μg−1 protein in iron-depleted cultures. A positive correlation between EC and microcystin content of the cells in both phosphorus- and iron-depleted cultures indicates that factors that affect EC influence microcystin production. Phosphorus and iron depletion modulated the cellular composition of M. aeruginosa. Carbohydrate constituted 5–8% of dry weight when the organisms were ...
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iron starvation increases toxicity of microcystis aeruginosa cya 228 1 Chroococcales cyanophyceae
Phycologia, 1996Co-Authors: Susanne Lyck, Nina Gjolme, Hans UtkilenAbstract:Abstract Toxin production and growth during iron starvation was studied in the toxic strain Microcystis aeruginosa (Kutzing) Lemmermann CYA 228/1 and the non-toxic strain M. aeruginosa CYA 143, using continuous culture. Iron starvation resulted in a 5-fold decrease in chlorophyll a content and a 3-fold decrease in the protein content in both organisms while a minor increase in dry weight was observed. The toxicity measured as the ratio of toxin to chlorophyll or toxin to protein was found to increase during iron starvation. During iron-depletion, the toxic strain of Microcystis maintained its cell vitality much longer than the non-toxic strain.
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Iron starvation increases toxicity of Microcystis aeruginosa CYA 228/1 (Chroococcales, Cyanophyceae)
Phycologia, 1996Co-Authors: Susanne Lyck, Nina Gjolme, Hans UtkilenAbstract:Abstract Toxin production and growth during iron starvation was studied in the toxic strain Microcystis aeruginosa (Kutzing) Lemmermann CYA 228/1 and the non-toxic strain M. aeruginosa CYA 143, using continuous culture. Iron starvation resulted in a 5-fold decrease in chlorophyll a content and a 3-fold decrease in the protein content in both organisms while a minor increase in dry weight was observed. The toxicity measured as the ratio of toxin to chlorophyll or toxin to protein was found to increase during iron starvation. During iron-depletion, the toxic strain of Microcystis maintained its cell vitality much longer than the non-toxic strain.
Luis Henrique Zanini Branco - One of the best experts on this subject based on the ideXlab platform.
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aerophytic cyanoprokaryotes from the atlantic rainforest region of sao paulo state brazil Chroococcales and oscillatoriales
Cryptogamie Algologie, 2009Co-Authors: Luis Henrique Zanini Branco, Lucien Hoffmann, Joana Pozzetti Teixeira, Viviani Ferreira, Jose Cesar De Morais FilhoAbstract:Puisque les algues sont principalement aquatiques, il semble presque paradoxal qu'il existe une flore du sol relativement diversifiee ou les cyanoprokaryotes aerophiles sont particulierement abondantes. Cependant, les etudes dans ce domaine ne sont pas tres nombreuses. Le present article se propose de contribuer a la connaissance taxonomique de la flore des cyanoprocaryotes Chroococcales et oscillatoriales dans les regions tropicales. Des echantillons de cyanoprokaryotes ont ete preleves dans une foret ombrophile de l'etat de Sao Paulo, Bresil. Les donnees sur le type et la couleur de la masse des cyanoprokaryotes, le type de substrat, la temperature et l'humidite de la masse et de l'air, le pH et les irradiances absolue et relative ont aussi ete enregistrees. L'etude a montre la presence de 24 especes appartenant aux ordres des Chroococcales et Oscillatoriales (12 especes chacun). Aphanothece (quatre especes) etait le genre le plus riche en especes. En general, la resolution taxonomique sur la base de donnees morphologiques et morphometriques peut parfois demeurer problematique.
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validation of the name stichosiphon mangle Chroococcales cyanophyta
Taxon, 1995Co-Authors: Luis Henrique Zanini Branco, Simone Maria F Silva, Celia Leite SantannaAbstract:Stichosiphon mangle Branco & al. (1994: 2) was proposed on the basis of material gathered in mangroves on Cardoso Island (Brazil) and Inhaca Island (Mozambique). The authors designated figures 1-19 of the protologue as the type. This designation of figures, however, is not permitted by Art. 8.3 of the Tokyo Code, because preserved collections exist. Moreover, the figures were of material from both Brazil and Mozambique and do not, therefore, represent a single element.