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Ulf Karsten - One of the best experts on this subject based on the ideXlab platform.
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polyols and uv sunscreens in the Prasiola clade trebouxiophyceae chlorophyta as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Polyols and UV‐sunscreens in the Prasiola‐clade (Trebouxiophyceae, Chlorophyta) as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Prasiolin, a new UV-sunscreen compound in the terrestrial green macroalga Prasiola calophylla (Carmichael ex Greville) Kützing
2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion—We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calophylla. Prasiola calophylla—(Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasiola species and other related Trebouxiophycean taxa synthesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elucidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M−1 cm−1, and could be identified as N-[5,6 hydroxy-5(hydroxymethyl)-2-methoxy-3-oxo-1-cycohexen-1-yl] glutamic acid using one- and two-dimensional 1H and 13C-NMR spectroscopy. As trivial name for this novel MAA we suggest ‘prasiolin’. The ecologically essential function of prasiolin for UVR-protection in terrestrial algae of the Trebouxiophyceae is discussed. This article is published with open access at Springerlink.comOpen Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International Licens
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prasiolin a new uv sunscreen compound in the terrestrial green macroalga Prasiola calophylla carmichael ex greville kutzing trebouxiophyceae chlorophyta
Planta, 2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calo- phylla. Prasiola calophylla (Carmichael ex Greville) Kutzing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasi- ola species and other related Trebouxiophycean taxa syn- thesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elu- cidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M -1 cm -1 , and could be identified as N-(5,6 hydroxy-5(hydroxymethyl)-2- methoxy-3-oxo-1-cycohexen-1-yl) glutamic acid using one- and two-dimensional 1 H and 13 C-NMR spectroscopy. As trivial name for this novel MAA we suggest 'prasiolin'. The ecologically essential function of prasiolin for UVR- protection in terrestrial algae of the Trebouxiophyceae is discussed.
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Thermo-chemical behaviour and chemical product formation from Polar seaweeds during intermediate pyrolysis
Journal of Analytical and Applied Pyrolysis, 2013Co-Authors: Katharina Kebelmann, Ulf Karsten, Andreas Hornung, Gareth GriffithsAbstract:Fundamental analytical pyrolysis studies of biomass from Polar seaweeds, which exhibit a different biomass composition than terrestrial and micro-algae biomass were performed via thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass-spectrometry (Py-GC/MS). The main reason for this study is the adaptation of these species to very harsh environments making them an interesting source for thermo-chemical processing for bioenergy generation and production of biochemicals via intermediate pyrolysis. Several macroalgal species from the Arctic region Kongsfjorden, Spitsbergen/Norway (Prasiola crispa, Monostroma arcticum, Polysiphonia arctica, Devaleraea ramentacea, Odonthalia dentata, Phycodrys rubens, Sphacelaria plumosa) and from the Antarctic peninsula, Potter Cove King George Island (Gigartina skottsbergii, Plocamium cartilagineum, Myriogramme manginii, Hymencladiopsis crustigena, Kallymenia antarctica) were investigated under intermediate pyrolysis conditions. TGA of the Polar seaweeds revealed three stages of degradation representing dehydration, devolatilization and decomposition of carbonaceous solids. The maximum degradation temperatures Prasiola crispa were observed within the range of 220-320 C and are lower than typically obtained by terrestrial biomass, due to divergent polysaccharide compositions. Biochar residues accounted for 33-46% and ash contents of 27-45% were obtained. Identification of volatile products by Py-GC/MS revealed a complexity of generated chemical compounds and significant differences between the species. A widespread occurrence of aromatics (toluene, styrene, phenol and 4-methylphenol), acids (acetic acid, benzoic acid alkyl ester derivatives, 2-propenoic acid esters and octadecanoic acid octyl esters) in pyrolysates was detected. Ubiquitous furan-derived products included furfural and 5-methyl-2-furaldehyde. As a pyran-derived compound maltol was obtained by one red algal species (P. rubens) and the monosaccharide d-allose was detected in pyrolysates in one green algal (P. crispa). Further unique chemicals detected were dianhydromannitol from brown algae and isosorbide from green algae biomass. In contrast, the anhydrosugar levoglucosan and the triterpene squalene was detected in a large number of pyrolysates analysed.
Anja Hartmann - One of the best experts on this subject based on the ideXlab platform.
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polyols and uv sunscreens in the Prasiola clade trebouxiophyceae chlorophyta as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Polyols and UV‐sunscreens in the Prasiola‐clade (Trebouxiophyceae, Chlorophyta) as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Prasiolin, a new UV-sunscreen compound in the terrestrial green macroalga Prasiola calophylla (Carmichael ex Greville) Kützing
2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion—We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calophylla. Prasiola calophylla—(Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasiola species and other related Trebouxiophycean taxa synthesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elucidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M−1 cm−1, and could be identified as N-[5,6 hydroxy-5(hydroxymethyl)-2-methoxy-3-oxo-1-cycohexen-1-yl] glutamic acid using one- and two-dimensional 1H and 13C-NMR spectroscopy. As trivial name for this novel MAA we suggest ‘prasiolin’. The ecologically essential function of prasiolin for UVR-protection in terrestrial algae of the Trebouxiophyceae is discussed. This article is published with open access at Springerlink.comOpen Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International Licens
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prasiolin a new uv sunscreen compound in the terrestrial green macroalga Prasiola calophylla carmichael ex greville kutzing trebouxiophyceae chlorophyta
Planta, 2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calo- phylla. Prasiola calophylla (Carmichael ex Greville) Kutzing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasi- ola species and other related Trebouxiophycean taxa syn- thesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elu- cidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M -1 cm -1 , and could be identified as N-(5,6 hydroxy-5(hydroxymethyl)-2- methoxy-3-oxo-1-cycohexen-1-yl) glutamic acid using one- and two-dimensional 1 H and 13 C-NMR spectroscopy. As trivial name for this novel MAA we suggest 'prasiolin'. The ecologically essential function of prasiolin for UVR- protection in terrestrial algae of the Trebouxiophyceae is discussed.
Fabio Rindi - One of the best experts on this subject based on the ideXlab platform.
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Prasiolales (Trebouxiophyceae, Chlorophyta) of the Svalbard Archipelago: diversity, biogeography and description of the new genera Prasionella and Prasionema
European Journal of Phycology, 2016Co-Authors: Svenja Heesch, Monica B J Moniz, Marie Pažoutová, Fabio RindiAbstract:AbstractSpecies of Prasiolales (Trebouxiophyceae, Chlorophyta) are among the most common terrestrial and freshwater algae in polar regions. Comprehensive molecular studies of this group are available for Antarctica, but not yet for Arctic regions. We examined the diversity of the Prasiolales in the Svalbard Archipelago combining morphological observations of field-collected material, culture studies, molecular data (plastid rbcL and tufA sequences) and literature records. We confirmed the widespread occurrence of Prasiola crispa and P. fluviatilis, species recorded from Spitsbergen since the 19th century. Molecular phylogenetic analyses led to the discovery of two new genera of Prasiolales. Prasionema payeri is morphologically identical to filamentous stages of P. crispa, but represents an early-diverging lineage in the order. Prasionella wendyae is a colonial alga reproducing by aplanospores; its phylogenetic position is among the basal lineages of the order, but it could not be reliably reconstructed du...
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tufa phylogeny and species boundaries in the green algal order Prasiolales trebouxiophyceae chlorophyta
Phycologia, 2014Co-Authors: Monica B J Moniz, Michael D. Guiry, Fabio RindiAbstract:The order Prasiolales is one of the most characteristic lineages of the green algal class Trebouxiophyceae. Although its phylogeny has been studied in detail in recent years, several important features of its systematics and taxonomy are still in need of clarification. We investigated the phylogeny of the tufA gene in the Prasiolales, a marker that has been recently proposed for DNA barcoding in green algae but for which the amount of sequence data available is still limited for the Trebouxiophyceae. The results produced a phylogeny that was in good agreement with previous studies based on other markers, and the concatenation of tufA, rbcL and psaB resulted in a substantial improvement in phylogenetic resolution. Prasiola meridionalis and Prasiola stipitata, the two most common marine species of Prasiola in the northern hemisphere, had identical tufA sequences; we interpreted this genetic similarity to be the result of a trans-Arctic radiation related to the climatic history of the northern Atlantic and n...
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MOLECULAR PHYLOGENY OF ANTARCTIC Prasiola (PrasiolaLES, TREBOUXIOPHYCEAE) REVEALS EXTENSIVE CRYPTIC DIVERSITY(1).
Journal of Phycology, 2012Co-Authors: Monica B J Moniz, Fabio Rindi, Phil M. Novis, Paul A. Broady, Michael D. GuiryAbstract:Trebouxiophytes of the genus Prasiola are well known in Antarctica, where they are among the most important primary producers. Although many aspects of their biology have been thoroughly investigated, the scarcity of molecular data has so far prevented an accurate assessment of their taxonomy and phylogenetic position. Using sequences of the chloroplast genes rbcL and psaB, we demonstrate the existence of three cryptic species that were previously confused under Prasiola crispa (Lightfoot) Kutzing. Genuine P. crispa occurs in Antarctica; its presence was confirmed by comparison with the rbcL sequence of the type specimen (from the Isle of Skye, Scotland). Prasiola antarctica Kutzing is resurrected as an independent species to designate algae with gross morphology identical to P. crispa but robustly placed in a separate lineage. The third species is represented by specimens identified as P. calophylla (Carmichael ex Greville) Kutzing in previous studies, but clearly separated from European P. calophylla (type locality: Argyll, Scotland); this alga is described as P. glacialis sp. nov. The molecular data demonstrated the presence of P. crispa in Maritime and Continental Antarctica. P. antarctica was recorded from the Antarctic Peninsula and Shetland Islands, and P. glacialis from the Southern Ocean islands and coast. Such unexpected cryptic diversity highlights the need for a taxonomic reassessment of many published Antarctic records of P. crispa. The results also indicate that marine species of Prasiola form a well-supported monophyletic group, whereas the phylogenetic diversity of freshwater species is higher than previously suspected (at least three separate lineages within the genus include species living in this type of environments).
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Reproduction and life history of the green alga Prasiola linearis Jao (Trebouxiophyceae, Chlorophyta)
Botanica Marina, 2010Co-Authors: Fabio RindiAbstract:Marine species of Prasiola are most common on rocky shores of the North Atlantic and North Pacific Oceans. Prasiola linearis is a little-known member of this group, whose known distribution is restricted to coastal marshes of Pacific North America. The little information available on this species is mostly based on the original description; its life history has not been previously reported. Reproduction and life history were investigated in a series of experiments conducted in different combinations of culture medium, temperature, daylength and photon irradiance. The alga reproduced by aplanospores that were produced in the apical part of the blade. Upon release, each aplanospore reproduced a new thallus; sexual reproduction, which occurs in other marine species of Prasiola (P. stipitata and P. meridionalis) was not observed in P. linearis. No variation in reproductive patterns was observed between different combinations of factors tested; however, the alga showed very weak growth at 208C. The life history of Prasiola linearis consists of a repetition of the same morphological phase reproducing by aplanospores. The diversity of life histories observed in marine species of Prasiola is illustrated and discussed.
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MOLECULAR PHYLOGENY OF THE GREEN ALGAL ORDER PrasiolaLES (TREBOUXIOPHYCEAE, CHLOROPHYTA)1
Journal of Phycology, 2007Co-Authors: Fabio Rindi, Lynne Mcivor, Michael D. Guiry, Alison R. Sherwood, Thomas Friedl, Robert G. SheathAbstract:The systematics of the Prasiolales was investigated by phylogenetic inference based on analyses of the rbcL and 18S rRNA genes for representatives of all four genera currently attributed to this order (Prasiococcus, Prasiola, Prasiolopsis, Rosenvingiella), including all type species. The rbcL gene had higher sequence divergence than the 18S rRNA gene and was more useful for phylogenetic inference at the ranks of genus and species. In the rbcL gene phylogeny, three main clades were observed, corresponding to Prasiola, Prasiolopsis, and Rosenvingiella. Prasiococcus was nested among species of Prasiola occurring in subaerial and supralittoral habitats. Trichophilus welckeri Weber Bosse, a subaerial alga occurring in the fur of sloths in Amazonia, was closely related to Prasiolopsis ramosa Vischer. The species of Prasiola were grouped into three well-supported clades comprising (i) marine species, (ii) freshwater and terrestrial species with linear blades, and (iii) terrestrial species with rounded or fan-shaped blades. Sequence divergence was unexpectedly low in the marine group, which included species with different morphologies. For the 18S rRNA gene, the phylogenetic analyses produced several clades observed for the rbcL gene sequence analysis, but, due to very little sequence variation, it showed considerably lower resolution for inference at the species and genus levels. Due to the low support of some internal branches, the results of the analyses did not allow an unambiguous clarification of the origin and the early evolution of the Prasiolales.
Markus Ganzera - One of the best experts on this subject based on the ideXlab platform.
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polyols and uv sunscreens in the Prasiola clade trebouxiophyceae chlorophyta as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Polyols and UV‐sunscreens in the Prasiola‐clade (Trebouxiophyceae, Chlorophyta) as metabolites for stress response and chemotaxonomy
Journal of Phycology, 2018Co-Authors: Vivien Hotter, Markus Ganzera, Anja Hartmann, Karin Glaser, Ulf KarstenAbstract:In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.
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Prasiolin, a new UV-sunscreen compound in the terrestrial green macroalga Prasiola calophylla (Carmichael ex Greville) Kützing
2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion—We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calophylla. Prasiola calophylla—(Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasiola species and other related Trebouxiophycean taxa synthesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elucidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M−1 cm−1, and could be identified as N-[5,6 hydroxy-5(hydroxymethyl)-2-methoxy-3-oxo-1-cycohexen-1-yl] glutamic acid using one- and two-dimensional 1H and 13C-NMR spectroscopy. As trivial name for this novel MAA we suggest ‘prasiolin’. The ecologically essential function of prasiolin for UVR-protection in terrestrial algae of the Trebouxiophyceae is discussed. This article is published with open access at Springerlink.comOpen Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International Licens
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prasiolin a new uv sunscreen compound in the terrestrial green macroalga Prasiola calophylla carmichael ex greville kutzing trebouxiophyceae chlorophyta
Planta, 2016Co-Authors: Anja Hartmann, Andreas Holzinger, Markus Ganzera, Ulf KarstenAbstract:Main conclusion We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calo- phylla. Prasiola calophylla (Carmichael ex Greville) Kutzing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasi- ola species and other related Trebouxiophycean taxa syn- thesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elu- cidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M -1 cm -1 , and could be identified as N-(5,6 hydroxy-5(hydroxymethyl)-2- methoxy-3-oxo-1-cycohexen-1-yl) glutamic acid using one- and two-dimensional 1 H and 13 C-NMR spectroscopy. As trivial name for this novel MAA we suggest 'prasiolin'. The ecologically essential function of prasiolin for UVR- protection in terrestrial algae of the Trebouxiophyceae is discussed.
A.h.l. Huiskes - One of the best experts on this subject based on the ideXlab platform.
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dna damage and photosynthetic performance in the antarctic terrestrial alga Prasiola crispa ssp antarctica chlorophyta under manipulated uv b radiation
Journal of Phycology, 2001Co-Authors: Anita G J Buma, W H Van De Poll, T C W Moerdijk, A.h.l. HuiskesAbstract:The effect of reduced, natural ambient, and enhanced UV-B radiation (UVBR) on photosynthesis and DNA damage in the Antarctic terrestrial alga Prasiola crispa ssp. antarctica (Kutzing) Knebel was investigated in two field experiments. Samples of P. crispa were collected underneath snow cover and exposed outside to reduced and natural UVBR in the austral spring. In a second experiment at the end of the austral summer, samples were exposed to ambient and enhanced UVBR. PSII efficiency, net photosynthetic rate (NP), dark respiration rate (DR), UV-absorbing pigments, and cyclobutyl pyrimidine dimer (CPD) formation were measured during the experiments. In October 1998, a spring midday maximum of 2.0 W .m(-2) of UVBR did not significantly affect effective quantum yield (DeltaF/F- m'), and a reduction in the ratio of variable to maximal fluorescence (F-v/F-m) in the late afternoon was transient. Exposure to natural ambient UVBR in October increased CPD values significantly. Midday maxima of UVBR during the experiments in October and January were comparable, but Setlow- DNA-weighted UVBR was more than 50% lower in January than in October. In January, 0.5 W .m(-2) additional UVBR during 10 h did not have a negative effect on DeltaF/F-m'. The reduction in F-v/F-m was not significant. NP and DR were not affected by supplementation of UVBR. Although photosynthetic activity remained largely unaffected by UVBR treatment, DNA damage was shown to be a sensitive parameter to monitor UVBR effects. Supplementation of additional UVBR did significantly enhance the amounts of CPD in exposed samples and repair took place overnight. It is concluded that PSII and whole-chain photosynthesis of P. crispa is well adapted to ambient and enhanced levels of UVBR but that CPD formation is more sensitive to UVBR than to photosynthesis. [KEYWORDS: Antarctica; chlorophyll; chlorophyll fluorescence; cyclobutyl pyrimidine dimers; DNA damage; photosynthesis; Prasiola crispa; terrestrial alga; thymine dimers; UV-B radiation; UV-B supplementation Ultraviolet-radiation; emiliania-huxleyi; depth-zonation; thymine dimers; marine diatom; amino-acids; high light; macroalgae; growth; phytoplankton]
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Morphological evidence for the symbiotic character of Turgidosculum complicatulum Kohlm. & Kohlm. (= Mastodia tesselata Hook.f. & Harvey)
Symbiosis, 2001Co-Authors: D. Lud, A.h.l. Huiskes, Sieglinde OttAbstract:The symbiotic nature of the association between mycobiont and photobiont in the Antarctic lichen Turgidosculum complicatulum has been questioned. Some authors consider the lichen T. complicatulum to be an alga parasitized by the fungus. The photobiont Prasiola crispa ssp. antarctica (Kutzing) Knebel also occurs free-living in adjacent microhabitats. The initial developmental stages of this Antarctic lichen or lichen-like association are described here for the first time. The aim of this study was to examine the early developmental stages of T. complicatulum in order to characterize the nature of the association between photobiont and mycobiont. SEM and light microscopy revealed a decisive role of unicellular aplanospores and other few-celled stages of the alga in the process of lichenization. There is a slight morphogenetic influence of the mycobiont on the photobiont, but no cortex differentiated. The outer layer of the thallus does not contain phenolic substances other than melanin. On the basis of morphological investigations and some physiological and chemical properties T. complicatulum fan be described as a lichen with simple organisational level, although certain features challenge usual concepts of lichen symbiosis. [KEYWORDS: development; initial stage; lichenization; Mastodia tesselata; mutualism; parasitism; Prasiola crispa; symbiosis; Turgidosculum complicatulum Antarctica; survival; fungus]
