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Beatriz Díez - One of the best experts on this subject based on the ideXlab platform.
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Fischerella thermalis: a model organism to study thermophilic diazotrophy, photosynthesis and multicellularity in cyanobacteria
Extremophiles, 2019Co-Authors: Jaime Alcorta, Pablo Vergara-barros, Laura A. Antonaru, María E. Alcamán-arias, Dennis J. Nürnberg, Beatriz DíezAbstract:The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus ) is widely distributed in hot springs around the world. Morphologically, it has been described as early as 1837. However, its taxonomic placement remains controversial. F. thermalis belongs to the same genus as mesophilic Fischerella species but forms a monophyletic clade of thermophilic Fischerella strains and sequences from hot springs. Their recent divergence from freshwater or soil true-branching species and the ongoing process of specialization inside the thermal gradient make them an interesting evolutionary model to study. F. thermalis is one of the most complex prokaryotes. It forms a cellular network in which the main trichome and branches exchange metabolites and regulators via septal junctions. This species can adapt to a variety of environmental conditions, with its photosynthetic apparatus remaining active in a temperature range from 15 to 58 °C. Together with its nitrogen-fixing ability, this allows it to dominate in hot spring microbial mats and contribute significantly to the de novo carbon and nitrogen input. Here, we review the current knowledge on the taxonomy and distribution of F. thermalis , its morphological complexity, and its physiological adaptations to an extreme environment.
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Temperature modulates Fischerella thermalis ecotypes in Porcelana Hot Spring
Systematic and applied microbiology, 2018Co-Authors: Jaime Alcorta, María E. Alcamán-arias, Sebastian Espinoza, Tomeu Viver, Nicole Trefault, Ramon Rosselló-móra, Beatriz DíezAbstract:In the Porcelana Hot Spring (Northern Patagonia), true-branching cyanobacteria are the dominant primary producers in microbial mats, and they are mainly responsible for carbon and nitrogen fixation. However, little is known about their metabolic and genomic adaptations at high temperatures. Therefore, in this study, a total of 81 Fischerella thermalis strains (also known as Mastigocladus laminosus) were isolated from mat samples in a thermal gradient between 61-46°C. The complementary use of proteomic comparisons from these strains, and comparative genomics of F. thermalis pangenomes, suggested that at least two different ecotypes were present within these populations. MALDI-TOF MS analysis separated the strains into three clusters; two with strains obtained from mats within the upper temperature range (61 and 54°C), and a third obtained from mats within the lower temperature range (51 and 46°C). Both groups possessed different but synonymous nifH alleles. The main proteomic differences were associated with the abundance of photosynthesis-related proteins. Three F. thermalis metagenome assembled genomes (MAGs) were described from 66, 58 and 48°C metagenomes. These pangenomes indicated a divergence of orthologous genes and a high abundance of exclusive genes at 66°C. These results improved the current understanding of thermal adaptation of F. thermalis and the evolution of these thermophilic cyanobacterial species.
Kurt O. Konhauser - One of the best experts on this subject based on the ideXlab platform.
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Genesis of large siliceous stromatolites at Frying Pan Lake, Waimangu geothermal field, North Island, New Zealand
Sedimentology, 2005Co-Authors: Brian Jones, Robin W. Renaut, Kurt O. KonhauserAbstract:Lilypad stromatolites, up to 3 m long and 1AE5 m wide, were found to be actively growing in the shallow marginal waters of Frying Pan Lake and its outflow channel. These stromatolites, composed of Phormidium (> 90%), Fischerella, and a variety of other microbes, develop through a series of distinct growth stages. Dark green microbial mats cover the floor of the outflow channel and give rise to columns of various sizes and shapes in the shallower marginal waters. Once the columns reach the water level, the mats spread laterally to form a lilypad stromatolite. The lilypads are characterized by a raised, dark green rim, 4‐5 mm high, that encircles a flat interior covered with a distinctive orange-red mat. The microbes forming the columns and lilypad plate are being actively silicified. The stromatolites are formed of: (i) flat-lying Phormidium filaments (P-laminae), (ii) upright filaments of Phormidium that are commonly associated with Fischerella (U-laminae), and (iii) mucus, diatoms and pyrite framboids (M-laminae). P-laminae dominate most of the columns, with tripartite cycles of P-, U-, to M-laminae being found mostly in the upper parts of the stromatolites. The transition from the P- to U-laminae is marked by a change in the growth pattern of the Phormidium and branching of Fischerella, which was probably triggered by a change in environmental conditions. In the Frying Pan Lake outflow channel, this change may be related to fluctuations in water level and flow rates that are caused by periods of heavy rain, seasonal changes, long-term variations in rainfall, and/or the unique 40-day hydrological cycle that exists between Frying Pan Lake and Inferno Crater, which is a nearby hydrothermal crater lake.
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Genesis of large siliceous stromatolites at Frying Pan Lake, Waimangu geothermal field
2005Co-Authors: Brian Jones, Robin W. Renaut, Kurt O. KonhauserAbstract:Lilypad stromatolites, up to 3 m long and 1Æ5 m wide, were found to be actively growing in the shallow marginal waters of Frying Pan Lake and its outflow channel. These stromatolites, composed of Phormidium (> 90%), Fischerella, and a variety of other microbes, develop through a series of distinct growth stages. Dark green microbial mats cover the floor of the outflow channel and give rise to columns of various sizes and shapes in the shallower marginal waters. Once the columns reach the water level, the mats spread laterally to form a lilypad stromatolite. The lilypads are characterized by a raised, dark green rim, 4–5 mm high, that encircles a flat interior covered with a distinctive orange-red mat. The microbes forming the columns and lilypad plate are being actively silicified. The stromatolites are formed of: (i) flat-lying Phormidium filaments (P-laminae), (ii) upright filaments of Phormidium that are commonly associated with Fischerella (U-laminae), and (iii) mucus, diatoms and pyrite framboids (M-laminae). P-laminae dominate most of the columns, with tripartite cycles of P-, U-, to M-laminae being found mostly in the upper parts of the stromatolites. The transition from the P- to U-laminae is marked by a change in the growth pattern of the Phormidium and branching of Fischerella, which was probably triggered by a change in environmental conditions. In the Frying Pan Lake outflow channel, this change may be related to fluctuations in water level and flow rates that are caused by periods of heavy rain, seasonal changes, long-term variations in rainfall, and/or the unique 40-day hydrological cycle that exists between Frying Pan Lake and Inferno Crater, which is a nearby hydrothermal crater lake
Sami Ray - One of the best experts on this subject based on the ideXlab platform.
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the study of cyanobacterial flora from geothermal springs of bakreswar west bengal india
Algae, 2009Co-Authors: Manoji Debnath, Narayan Chandra Mandal, Sami RayAbstract:Geothermal springs in India, formed as a result of volcanic or tectonic activities, are characterized by high temperature and relatively abundant reduced compounds. These thermal springs are inhabited by characteristic thermophilic organisms including cyanobacteria. Cyanobacteria are among the few organisms that can occupy high temperature aquatic environments including hot springs. In alkaline and neutral hot springs and streams flowing from them cyanobacteria can form thick colourful mats that exhibit banding patterns. The present investigation involves study of mat forming cyanobacterial flora from hot springs located in Bakreswar, West Bengal, India. The important species found are Synechococcus bigranulatus, S. lividus, Gloeocapsa gelatinosa, G. muralis, Phormidium laminosum, P. frigidum, Oscillatoria princes, O. fragilis, Lyngbya lutea, Pseudanabaena sp., Calothrix thermalis, and Fischerella thermalis. Their distribution pattern in relation to physico-chemical parameters of spring water has also been studied. Three cyanobacterial strains of the above mentioned list were grown in culture and their pigment content and nitrogen fixing capacity were also studied. Nitrogen fixing capacities of Calothrix thermalis, Nostoc sp. (isolated in culture) and Fischerella thermalis are 5.14, 0.29, and 2.60 n mole C2H4/µg of Chl-a/hr respectively. Carotenoid : Chlorophyll-a ratio of four mat samples collected from Kharkunda, Suryakunda, Dudhkunda and bathing pool are 2.45, 1.60, 1.48, and 1.34, respectively. Higher value of Carotenoid : Chlorophyll-a ratio coincided with higher temperature.
Jaime Alcorta - One of the best experts on this subject based on the ideXlab platform.
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Fischerella thermalis: a model organism to study thermophilic diazotrophy, photosynthesis and multicellularity in cyanobacteria
Extremophiles, 2019Co-Authors: Jaime Alcorta, Pablo Vergara-barros, Laura A. Antonaru, María E. Alcamán-arias, Dennis J. Nürnberg, Beatriz DíezAbstract:The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus ) is widely distributed in hot springs around the world. Morphologically, it has been described as early as 1837. However, its taxonomic placement remains controversial. F. thermalis belongs to the same genus as mesophilic Fischerella species but forms a monophyletic clade of thermophilic Fischerella strains and sequences from hot springs. Their recent divergence from freshwater or soil true-branching species and the ongoing process of specialization inside the thermal gradient make them an interesting evolutionary model to study. F. thermalis is one of the most complex prokaryotes. It forms a cellular network in which the main trichome and branches exchange metabolites and regulators via septal junctions. This species can adapt to a variety of environmental conditions, with its photosynthetic apparatus remaining active in a temperature range from 15 to 58 °C. Together with its nitrogen-fixing ability, this allows it to dominate in hot spring microbial mats and contribute significantly to the de novo carbon and nitrogen input. Here, we review the current knowledge on the taxonomy and distribution of F. thermalis , its morphological complexity, and its physiological adaptations to an extreme environment.
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Temperature modulates Fischerella thermalis ecotypes in Porcelana Hot Spring
Systematic and applied microbiology, 2018Co-Authors: Jaime Alcorta, María E. Alcamán-arias, Sebastian Espinoza, Tomeu Viver, Nicole Trefault, Ramon Rosselló-móra, Beatriz DíezAbstract:In the Porcelana Hot Spring (Northern Patagonia), true-branching cyanobacteria are the dominant primary producers in microbial mats, and they are mainly responsible for carbon and nitrogen fixation. However, little is known about their metabolic and genomic adaptations at high temperatures. Therefore, in this study, a total of 81 Fischerella thermalis strains (also known as Mastigocladus laminosus) were isolated from mat samples in a thermal gradient between 61-46°C. The complementary use of proteomic comparisons from these strains, and comparative genomics of F. thermalis pangenomes, suggested that at least two different ecotypes were present within these populations. MALDI-TOF MS analysis separated the strains into three clusters; two with strains obtained from mats within the upper temperature range (61 and 54°C), and a third obtained from mats within the lower temperature range (51 and 46°C). Both groups possessed different but synonymous nifH alleles. The main proteomic differences were associated with the abundance of photosynthesis-related proteins. Three F. thermalis metagenome assembled genomes (MAGs) were described from 66, 58 and 48°C metagenomes. These pangenomes indicated a divergence of orthologous genes and a high abundance of exclusive genes at 66°C. These results improved the current understanding of thermal adaptation of F. thermalis and the evolution of these thermophilic cyanobacterial species.
Gregory M. L. Patterson - One of the best experts on this subject based on the ideXlab platform.
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Oxidized welwitindolinones from terrestrial Fischerella spp
Journal of natural products, 1999Co-Authors: Jorge I. Jiménez, Richard E. Moore, Udo Huber, Gregory M. L. PattersonAbstract:3-Hydroxy-N-methylwelwitindolinone C isonitrile (3), 3-hydroxy-N-methylwelwitindolinone C isothiocyanate (4), and the novel cyclic ether N-methylwelwitindolinone D isonitrile (6) are three new alkaloids from two terrestrial Fischerella spp. belonging to the Stigonemataceae. Photooxidation of N-methylwelwitindolinone C isonitrile (1) leads to isonitriles 3 and 6. Isonitrile 3 is readily hydrated to 3-hydroxy-N-methylwelwitindolinone C formamide (5), an artifact produced during the isolation procedure.
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Fischerindole L, a new isonitrile from the terrestrial blue-green alga Fischerella muscicola
Tetrahedron Letters, 1992Co-Authors: Aeri Park, Richard E. Moore, Gregory M. L. PattersonAbstract:Abstract Fischerindole L ( 3 ) is a novel octahydroindeno[2,1- b ]indole isonitrile from the terrestrial cyanophyte Fischerella muscicola that possesses the same relative stereochemistry as hapalindole L ( 4 ).