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1
Rasha Hamdy, Rasha Hamdy. "Diversity and Distribution of Polychaetes Associated with Macroalgae along the Alexandria Coast, Egypt". journal of king abdulaziz university marine science 28, n. 2 (4 febbraio 2018): 67–79. http://dx.doi.org/10.4197/mar.28-2.5.
Testo completoAbstract (sommario):
The relationship between benthic macroalgae and associated polychaetes was studied monthly from October 2014 to October 2015 along the Alexandria coast, Egypt. A total of 56 polychaete species were found among 28 macroalgal species, which belonging to green, brown and red algae. The red algae hosted pronouncedly higher number of polychaete species than the brown and green algae, particularly during winter and spring, while green algae were associated with higher number of polychaete species in January, April, August and October 2015. In contrast, the average count of polychaete individuals associated with the green algae was higher in winter and autumn than that recorded with the red algae, while low with both red and green algae in spring and summer, and very poor within the brown algae. The present study revealed that the structure of algal species my affect the diversity and abundance of the associated polychaetes and the diversity of these worms varied among the hosting algal species.
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Brawley, Susan H., Nicolas A. Blouin, Elizabeth Ficko-Blean, Glen L. Wheeler, Martin Lohr, Holly V. Goodson, Jerry W. Jenkins et al. "Insights into the red algae and eukaryotic evolution from the genome ofPorphyra umbilicalis(Bangiophyceae, Rhodophyta)". Proceedings of the National Academy of Sciences 114, n. 31 (17 luglio 2017): E6361—E6370. http://dx.doi.org/10.1073/pnas.1703088114.
Testo completoAbstract (sommario):
Porphyra umbilicalis(laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploidPorphyragenome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of thePorphyragenome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-tolerance mechanisms including photoprotection. Cytoskeletal motor proteins inPorphyraare restricted to a small set of kinesins that appear to be the only universal cytoskeletal motors within the red algae. Dynein motors are absent, and most red algae, includingPorphyra, lack myosin. This surprisingly minimal cytoskeleton offers a potential explanation for why red algal cells and multicellular structures are more limited in size than in most multicellular lineages. Additional discoveries further relating to the stress tolerance of bangiophytes include ancestral enzymes for sulfation of the hydrophilic galactan-rich cell wall, evidence for mannan synthesis that originated before the divergence of green and red algae, and a high capacity for nutrient uptake. Our analyses provide a comprehensive understanding of the red algae, which are both commercially important and have played a major role in the evolution of other algal groups through secondary endosymbioses.
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Mikhaylova, T. A. "Vegetation of the red algal belt of the White Sea (European Arctic, Russia)". Novosti sistematiki nizshikh rastenii 53, n. 1 (2019): 39–65. http://dx.doi.org/10.31111/nsnr/2019.53.1.39.
Testo completoAbstract (sommario):
In 2016–2018, during the summer period, the first detail studies of the red algal belt of the White Sea were carried out time with SCUBA diving at the Chupa Inlet, near the Cape Kartesh, and at the Kolvitsa Inlet (the Kandalaksha Bay), in the vicinity of Sonostrov Island (the White Sea Basin) and Bolshoy Zhuzhmuy Island (the Onega Bay). The upper boundary of the red algal belt lies at a depth of about 7 m, and the lower boundary, at a depth of about 20 m. In the White Sea, the algae distribution in the lower part of the photic zone depends on the geomorphological structure of the bottom and on the composition of the accompanying sedentary fauna, so the lower boundary may vary in the depth range from 14 down to 23 m. In total, 87 species of algae belonging to the three large taxonomic groups have been registered: Chlorophyta (13), Phaeophyceae (33), and Rhodophyta (41). Significant richness of the species composition, vertical zoning, and a variety of phytocoenoses of the red algal belt in different parts of the White Sea have been found. Phytocoenoses of the red algal belt refer to three associations: ass. Odonthalia dentata(–Pseudolithoderma extensum), ass. Phycodrys rubens+Coccotylus truncatus(–Pseudolithoderma extensum), and ass. Lithothamnion glaciale. Nineteen species of macrophytes were the most common and characteristic representatives of the red algal belt, including thirteen species of red algae, four species of brown algae, and two species of green algae. It has been found that abundant and characteristic species of the red algal belt have an additional edificatory function in the studied phytocoenoses, being the consorts that carry rich epiflora and form favorable conditions for increasing the species diversity of algae in the lower phytal zone. The observed rapid shrinkage of the depth range of the kelp and red algal belts, as well as the changes in the vertical distribution of some other algal species in the White Sea, require specific attention concerning altering of their habitat conditions.
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Rockwell, Nathan C., Deqiang Duanmu, Shelley S. Martin, Charles Bachy, Dana C. Price, Debashish Bhattacharya, Alexandra Z. Worden e J. Clark Lagarias. "Eukaryotic algal phytochromes span the visible spectrum". Proceedings of the National Academy of Sciences 111, n. 10 (24 febbraio 2014): 3871–76. http://dx.doi.org/10.1073/pnas.1401871111.
Testo completoAbstract (sommario):
Plant phytochromes are photoswitchable red/far-red photoreceptors that allow competition with neighboring plants for photosynthetically active red light. In aquatic environments, red and far-red light are rapidly attenuated with depth; therefore, photosynthetic species must use shorter wavelengths of light. Nevertheless, phytochrome-related proteins are found in recently sequenced genomes of many eukaryotic algae from aquatic environments. We examined the photosensory properties of seven phytochromes from diverse algae: four prasinophyte (green algal) species, the heterokont (brown algal) Ectocarpus siliculosus, and two glaucophyte species. We demonstrate that algal phytochromes are not limited to red and far-red responses. Instead, different algal phytochromes can sense orange, green, and even blue light. Characterization of these previously undescribed photosensors using CD spectroscopy supports a structurally heterogeneous chromophore in the far-red–absorbing photostate. Our study thus demonstrates that extensive spectral tuning of phytochromes has evolved in phylogenetically distinct lineages of aquatic photosynthetic eukaryotes.
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Lewin, Ralph A. "Algae in red". Nature 360, n. 6400 (novembre 1992): 119–20. http://dx.doi.org/10.1038/360119a0.
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Ghosh, Amit K., e Suman Sarkar. "Contemporary taxonomic perspectives of fossil Coralline Red Algae: their possible origin and evolution". Journal of Palaeosciences 59, n. (1-3) (31 dicembre 2010): 107–19. http://dx.doi.org/10.54991/jop.2010.193.
Testo completoAbstract (sommario):
Studies done by various phycologists have brought about remarkable changes in the present-day coralline algal taxonomy. The taxonomy of fossil coralline red algae also has been under the process of continuous revision and modification since 1993. Prior to 1993 it was believed that several diagnostic characters used in recent coralline red algae were unpreservable in fossil forms. Palaeoalgologists have now understood the value of unification of taxonomy, for extant and fossil corallines to accurately interpret the phylogeny, palaeoecology and palaeobiogeography. Phylogenetically, the corallines are very important as they represent a major evolutionary line within the red algae as evidenced by anatomical studies on recent forms as well as various studies on gene sequence analysis. The present contribution deals with the remarkable changes that have taken place since 1993 in the taxonomic aspects of fossil coralline algae and the modern trends of research in this context. Presently, an attempt has been made to establish the possible origin and evolution of coralline red algae.
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Wen, Xianying, Giuseppe C. Zuccarello, Tatyana A. Klochkova e Gwang Hoon Kim. "Oomycete pathogens, red algal defense mechanisms and control measures". Algae 38, n. 4 (15 dicembre 2023): 203–15. http://dx.doi.org/10.4490/algae.2023.38.12.13.
Testo completoAbstract (sommario):
Oomycete pathogens are one of the most serious threats to the rapidly growing global algae aquaculture industry but research into how they spread and how algae respond to infection is unresolved, let alone a proper classification of the pathogens. Even the taxonomy of the genera <i>Pythium</i> and <i>Olpidiopsis</i>, which contain the most economically damaging pathogens in red algal aquaculture, and are among the best studied, needs urgent clarification, as existing morphological classifications and molecular evidence are often inconsistent. Recent studies have reported a number of genes involved in defense responses against oomycete pathogens in red algae, including pattern-triggered immunity and effectortriggered immunity. Accumulating evidence also suggests that calcium-mediated reactive oxygen species signaling plays an important role in the response of red algae to oomycete pathogens. Current management strategies to control oomycete pathogens in aquaculture are based on the high resistance of red algae to abiotic stress, these have environmental consequences and are not fully effective. Here, we compile a revised list of oomycete pathogens known to infect marine red algae and outline the current taxonomic situation. We also review recent research on the molecular and cellular responses of red algae to oomycete infection that has only recently begun, and outline the methods currently used to control disease in the field.
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Hultgren, Kristin M., e Hannah Mittelstaedt. "Color change in a marine isopod is adaptive in reducing predation". Current Zoology 61, n. 4 (1 agosto 2015): 739–48. http://dx.doi.org/10.1093/czoolo/61.4.739.
Testo completoAbstract (sommario):
Abstract Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea (Idotea) wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats (the brown alga Fucus distichus and the red alga Odonthalia floccosa) matched the color of their respective algal habitats, and also differed significantly in body size: smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation experiments demonstrated these color differences had fitness benefits: brown isopods that matched their brown algae habitats survived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that background matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods.
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Khan, Alia L., Heidi M. Dierssen, Ted A. Scambos, Juan Höfer e Raul R. Cordero. "Spectral characterization, radiative forcing and pigment content of coastal Antarctic snow algae: approaches to spectrally discriminate red and green communities and their impact on snowmelt". Cryosphere 15, n. 1 (13 gennaio 2021): 133–48. http://dx.doi.org/10.5194/tc-15-133-2021.
Testo completoAbstract (sommario):
Abstract. Here, we present radiative forcing (RF) estimates by snow algae in the Antarctic Peninsula (AP) region from multi-year measurements of solar radiation and ground-based hyperspectral characterization of red and green snow algae collected during a brief field expedition in austral summer 2018. Our analysis includes pigment content from samples at three bloom sites. Algal biomass in the snow and albedo reduction are well-correlated across the visible spectrum. Relative to clean snow, visibly green patches reduce snow albedo by ∼40 % and red patches by ∼20 %. However, red communities absorb considerably more light per milligram of pigment compared to green communities, particularly in green wavelengths. Based on our study results, it should be possible to differentiate red and green algae using Sentinel-2 bands in blue, green and red wavelengths. Instantaneous RF averages were double for green (180 W m−2) vs. red communities (88 W m−2), with a maximum of 228 W m−2. Based on multi-year solar radiation measurements at Palmer Station, this translated to a mean daily RF of ∼26 W m−2 (green) and ∼13 W m−2 (red) during peak growing season – on par with midlatitude dust attributions capable of advancing snowmelt. This results in ∼2522 m3 of snow melted by green-colored algae and ∼1218 m3 of snow melted by red-colored algae annually over the summer, suggesting snow algae play a significant role in snowmelt in the AP regions where they occur. We suggest impacts of RF by snow algae on snowmelt be accounted for in future estimates of Antarctic ice-free expansion in the AP region.
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Rajanikanth, A. "Rock building Cretaceous - Tertiary algae from India - an ecological perspective". Journal of Palaeosciences 40 (31 dicembre 1991): 399–412. http://dx.doi.org/10.54991/jop.1991.1790.
Testo completoAbstract (sommario):
Fossil benthonic photosynthetic algae capable of calcification contributed to the formation of Indian Cretaceous-Tertiary carbonate deposits. A comparative assessment of different marine calcareous algal assemblages known from various sedimentary basins and their ecological requirements have been highlighted. A comprehensive synthesis and retrospect of research on calcareous algae demonstrate extensive growth of green and red algae during Cretaceous-Tertiary times in India. The calcareous blue-green algae are feebly represented in the Cretaceous deposits and not recorded from the Tertiary deposits. Various ecological factors determined the distribution of different calcareous algal groups. An apparent extinction of calcareous algae is attributed to gaps in our knowledge and evolutionary changes.
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Patron, Nicola J., Matthew B. Rogers e Patrick J. Keeling. "Gene Replacement of Fructose-1,6-Bisphosphate Aldolase Supports the Hypothesis of a Single Photosynthetic Ancestor of Chromalveolates". Eukaryotic Cell 3, n. 5 (ottobre 2004): 1169–75. http://dx.doi.org/10.1128/ec.3.5.1169-1175.2004.
Testo completoAbstract (sommario):
ABSTRACT Plastids (photosynthetic organelles of plants and algae) are known to have spread between eukaryotic lineages by secondary endosymbiosis, that is, by the uptake of a eukaryotic alga by another eukaryote. But the number of times this has taken place is controversial. This is particularly so in the case of eukaryotes with plastids derived from red algae, which are numerous and diverse. Despite their diversity, it has been suggested that all these eukaryotes share a recent common ancestor and that their plastids originated in a single endosymbiosis, the so-called “chromalveolate hypothesis.” Here we describe a novel molecular character that supports the chromalveolate hypothesis. Fructose-1,6-bisphosphate aldolase (FBA) is a glycolytic and Calvin cycle enzyme that exists as two nonhomologous types, class I and class II. Red algal plastid-targeted FBA is a class I enzyme related to homologues from plants and green algae, and it would be predicted that the plastid-targeted FBA from algae with red algal secondary endosymbionts should be related to this class I enzyme. However, we show that plastid-targeted FBA of heterokonts, cryptomonads, haptophytes, and dinoflagellates (all photosynthetic chromalveolates) are class II plastid-targeted enzymes, completely unlike those of red algal plastids. The chromalveolate enzymes form a strongly supported group in FBA phylogeny, and their common possession of this unexpected plastid characteristic provides new evidence for their close relationship and a common origin for their plastids.
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Uryupova, Ekaterina F., Vassily A. Spiridonov e Dmitry G. Zhadan. "Amphipods (Crustacea: Amphipoda) associated with red algae (Rhodophyta) in Kandalaksha Bay (the White Sea, Russia)". Journal of the Marine Biological Association of the United Kingdom 92, n. 2 (6 dicembre 2011): 265–73. http://dx.doi.org/10.1017/s0025315411001676.
Testo completoAbstract (sommario):
Amphipods' assemblages living in the red algae communities were studied in Velikaya Salma Strait (Kandalaksha Bay, north-western White Sea) in the depth range of 3–11 m. Sampling sites were located along the depth and shore exposure gradients in the areas with a significant number of rhodophytes. In total 12 species of amphipods were found with Ampithoe rubricata and Crassicorophium bonellii being most common and abundant. Gammaropsis melanops and Pleusymtes glaber were revealed as subdominant species. As an algal grazer A. rubricata appeared to be the species most closely associated with various algal assemblages. Crassicorophium bonellii were found on substrates being a deposit feeder predominantly inhabiting mixed assemblages of red algae where deposition and accumulation of seston most likely took place. Gammaropsis melanops and P. glaber are known as grazers but they preferred the habitats with both red algae and sponges. None of the species can be considered as obligate inhabitants of red algae hosts. Ampithoe rubricata and C. bonellii occurred in red algae communities in the shallow area (about 4 m). The most diverse and quantitatively rich amphipod assemblages were found at depths of 8–9 m in the area protected from waves and surf by the islands. Three of the most common and abundant species A. rubricata, C. bonellii and P. glaber are considered as amphiboreal while most of the species associated with rhodophytes belong to the Arctic-boreal ones. Amphiboreal species are presumably adapted to a broader temperature-range, in particular to higher summer temperature, than the Arctic-boreal species; they most likely have an advantage when occupying biotopes at shallow subtidal depth with local conditions in the White Sea.
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Zakiryanov, I. G., V. A. Luchinina e N. V. Sennikov. "MICROFACIES AND PALEOALGOLOGICAL COMPLEXES OF CARBONATES OF THE UPPER ORDOVICIAN TACHALOV SECTION (WEST OF GORNY ALTAI)". Geology and mineral resources of Siberia 2, n. 4 (dicembre 2023): 109–18. http://dx.doi.org/10.20403/2078-0575-2023-4b-109-118.
Testo completoAbstract (sommario):
The article presents the study results of carbonaceous rocks and taxonomic diversity of the Upper Ordovician calcareous algae of the Tachalov section left half, located on the left side of the same-name creek in the central district of the Charysh-Inya structure-facies zone of Gorny Altai. Six microfacies are distinguished in rocks: algal-bacterial boundstones, crinoid mudstones, crinoid-algal wackestones, polybioclastic wackestones, crinoid-algal packstone-wackestones and crinoid-algal packstones. Calcareous algae of the following genera were recorded in limestones: Proaulopora Volgdin, 1934 (Ms), Girvanella Nicholson et Etheridge, 1878, Vermiporella Stolley, 1893, Apidium Stolley, 1896, Ortonella Garwood, 1914, Contexta Gnilovskaja, 1972, Halysis Høeg, 1932, Rothpletzella Wood, 1948. It is found, that during the formation of biohermal buildups in more active hydrodynamics, different groups of calcareous algae react either by increasing species diversity (like green algae) or by increasing the number of organisms of the same species (like red algae).
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RAGAN, MARK A., e ROBIN R. GUTELL. "Are red algae plants?" Botanical Journal of the Linnean Society 118, n. 2 (giugno 1995): 81–105. http://dx.doi.org/10.1111/j.1095-8339.1995.tb00463.x.
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RAGAN, M., e R. GUTELL. "Are red algae plants?" Botanical Journal of the Linnean Society 118, n. 2 (giugno 1995): 81–105. http://dx.doi.org/10.1016/s0024-4074(95)80010-7.
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Barcytė, Dovilė. "Extremophilic red algae reordered". Journal of Phycology 59, n. 3 (giugno 2023): 441–43. http://dx.doi.org/10.1111/jpy.13328.
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Onuma, Yukihiko, Nozomu Takeuchi, Sota Tanaka, Naoko Nagatsuka, Masashi Niwano e Teruo Aoki. "Physically based model of the contribution of red snow algal cells to temporal changes in albedo in northwest Greenland". Cryosphere 14, n. 6 (29 giugno 2020): 2087–101. http://dx.doi.org/10.5194/tc-14-2087-2020.
Testo completoAbstract (sommario):
Abstract. Surface albedo of snow and ice is substantially reduced by inorganic impurities, such as aeolian mineral dust (MD) and black carbon (BC), and also by organic impurities, such as microbes that live in the snow. In this paper, we present the temporal changes of surface albedo, snow grain size, MD, BC and snow algal cell concentration observed on a snowpack in northwest Greenland during the ablation season of 2014 and our attempt to reproduce the changes in albedo with a physically based snow albedo model. We also attempt to reproduce the effects of inorganic impurities and the red snow algae (Sanguina nivaloides) on albedo. Concentrations of MD and red snow algae in the surface snow were found to increase in early August, while snow grain size and BC were found to not significantly change throughout the ablation season. Surface albedo was found to have decreased by 0.08 from late July to early August. The albedo simulated by the model agreed with the albedo observed during the study period. However, red snow algae exerted little effect on surface albedo in early August. This is probably owing to the abundance of smaller cells (4.9×104 cells L−1) when compared with the cell abundance of red snow reported by previous studies in the Arctic region (∼108 cells L−1). The simulation of snow albedo until the end of the melting season, with a snow algae model, revealed that the reduction in albedo attributed to red snow algae could equal 0.004, out of a total reduction of 0.102 arising from the three impurities on a snowpack in northwest Greenland. Finally, we conducted scenario simulations using the snow albedo model, coupled with the snow algae model, in order to simulate the possible effects of red snow blooming on snow albedo under warm conditions in northwest Greenland. The result suggests that albedo reduction by red snow algal growth under warm conditions (surface snow temperature of +1.5 ∘C) reached 0.04, equivalent to a radiative forcing of 7.5 W m−2 during the ablation season of 2014. This coupled albedo model has the potential to dynamically simulate snow albedo, including the effect of organic and inorganic impurities, leading to proper estimates of the surface albedo of snow cover in Greenland.
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Williamson, Bo, Paul W. Gabrielson e Margarita Brandt. "First report of any species of the red algal order Nemaliales from mainland Ecuador: Neoizziella asiatica (Liagoraceae, Rhodophyta)". Botanica Marina 65, n. 2 (28 febbraio 2022): 135–39. http://dx.doi.org/10.1515/bot-2021-0092.
Testo completoAbstract (sommario):
Abstract The benthic marine algae of the mainland coast of Ecuador are poorly known mainly due to a lack of collections. Currently, DNA barcoding is the preferred method to identify species of benthic marine algae worldwide, as morpho-anatomical characters are inadequate to distinguish many species of macroalgae. We used the red algal barcode rbcL-3P to identify specimens collected in January 2020 from Manabí, Ecuador as Neoizziella asiatica. This is the first member of the red algal order Nemaliales to be reported from the mainland coast of Ecuador and extends the distribution of this alga by 1,100 km to the south from Panama.
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N'Yeurt, Antoine D. R., e Claude E. Payri. "A preliminary annotated checklist of the marine algae and seagrasses of the Wallis Islands (French Overseas Territory of Wallis and Futuna), South Pacific". Australian Systematic Botany 17, n. 4 (2004): 367. http://dx.doi.org/10.1071/sb03027.
Testo completoAbstract (sommario):
A total of 194 species of marine algae (14 Cyanobacteria, 41 Chlorophyta, 11 Heterokontophyta and 128 Rhodophyta), as well as three species of seagrasses, represent the first published records for the isolated island of Wallis, South Pacific. The flora has its strongest affinities with Fiji and Rotuma, followed by Samoa and French Polynesia. The lack of diverse habitats and its geographical location are invoked to explain the relatively low species richness compared with localities such as Fiji and Samoa. The flora has a typically tropical component dominated by encrusting coralline red algae, the calcified green algal genera Halimeda, and assemblages of Cyanobacteria. Normally ubiquitous species such as Halimeda discoidea, and the brown algal genera Hydroclathrus, Colpomenia, Rosenvingea, Asteronema, and Chnoospora are notably absent from the island, perhaps due to seasonality and the lack of suitable habitats. The minute epiphytic red alga Acrochaetium kurogii is reported for the first time outside of its type locality in Japan, while two as yet unidentified species of red algae (Gracilaria sp. and Sebdenia sp.) could represent new taxa if further useful material is found.
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Loganathan, Nitin, Yi-Chin Candace Tsai e Oliver Mueller-Cajar. "Characterization of the heterooligomeric red-type rubisco activase from red algae". Proceedings of the National Academy of Sciences 113, n. 49 (21 novembre 2016): 14019–24. http://dx.doi.org/10.1073/pnas.1610758113.
Testo completoAbstract (sommario):
The photosynthetic CO2-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) is inhibited by nonproductive binding of its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates. Reactivation requires ATP-hydrolysis–powered remodeling of the inhibited complexes by diverse molecular chaperones known as rubisco activases (Rcas). Eukaryotic phytoplankton of the red plastid lineage contain so-called red-type rubiscos, some of which have been shown to possess superior kinetic properties to green-type rubiscos found in higher plants. These organisms are known to encode multiple homologs of CbbX, the α-proteobacterial red-type activase. Here we show that the gene products of two cbbX genes encoded by the nuclear and plastid genomes of the red algae Cyanidioschyzon merolae are nonfunctional in isolation, but together form a thermostable heterooligomeric Rca that can use both α-proteobacterial and red algal-inhibited rubisco complexes as a substrate. The mechanism of rubisco activation appears conserved between the bacterial and the algal systems and involves threading of the rubisco large subunit C terminus. Whereas binding of the allosteric regulator RuBP induces oligomeric transitions to the bacterial activase, it merely enhances the kinetics of ATP hydrolysis in the algal enzyme. Mutational analysis of nuclear and plastid isoforms demonstrates strong coordination between the subunits and implicates the nuclear-encoded subunit as being functionally dominant. The plastid-encoded subunit may be catalytically inert. Efforts to enhance crop photosynthesis by transplanting red algal rubiscos with enhanced kinetics will need to take into account the requirement for a compatible Rca.
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Mshiywa, Faith Masilive, Shelley Edwards e Graeme Bradley. "Rhodophyta DNA Barcoding: Ribulose-1, 5-Bisphosphate Carboxylase Gene and Novel Universal Primers". International Journal of Molecular Sciences 25, n. 1 (19 dicembre 2023): 58. http://dx.doi.org/10.3390/ijms25010058.
Testo completoAbstract (sommario):
Red algae (Rhodophyta) are a heterogeneous group of marine algal species that have served as a source of high-value molecules, including antioxidants and scaffolds, for novel drug development. However, it is challenging to identify Rhodophytes through morphological features alone, and in most instances, that has been the prevailing approach to identification. Consequently, this study undertook the identification of red algae species in Kenton-on-Sea, South Africa, as a baseline for future research on red algae biodiversity and conservation. The identification was achieved by designing, analysing, and using a set of universal primers through DNA barcoding of the rbcL gene. The PCR products of the rbcL gene were sequenced, and 96% of the amplicons were successfully sequenced from this set and matched with sequences on BOLD, which led to these species being molecularly described. Amongst these species are medicinally essential species, such as Laurencia natalensis and Hypnea spinella, and potential cryptic species. This calls for further investigation into the biodiversity of the studied region. Meanwhile, the availability of these primers will ease the identification process of red algae species from other coastal regions.
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Rajopadhyaya, Ritu, e Shiva Kumar Rai. "Some freshwater algae from Bagh-Jhoda wetland, Morang: new for Nepal". Journal of Natural History Museum 30 (1 dicembre 2018): 15–27. http://dx.doi.org/10.3126/jnhm.v30i0.27375.
Testo completoAbstract (sommario):
Present paper describes new and interesting algae reported during the exploration of algal flora of Bagh-Jhoda wetland, Morang. A total of 20 species of freshwater algae, excluding cyanobacteria, have been reported from this wetland as new for Nepal. They were Ankistrodesmus spiralis, Botryococcus braunii, B. protuberans, Glaucocystis duplex, Gonium sociale, Kirchneriella contorta, Nephrocytium hydrophilum, N.obesum, Oocystiseremosphaeria, Sorastrum americanum, Staurastrum pseudosebaldi, S. striolatum var. divergens, S. subpolymorphum, Glenodinium borgei, Peridinium gatunense, Gomphonema lacusrankaloides, G. pseudoaugur, Nitzschia cf. pumila, Pinnularia amabilis and Ulnaria capitata. This wetland area is rich in algal diversity including red algae and it needs further extensive exploration.
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Rai, Dilli Ram, e Shiva Kumar Rai. "Freshwater Algae (Excluding Diatoms and Red Algae) from Hasina Wetland, Sundar Haraicha, Morang, Nepal". Himalayan Journal of Science and Technology 2 (1 dicembre 2018): 1–12. http://dx.doi.org/10.3126/hijost.v2i0.25834.
Testo completoAbstract (sommario):
This paper described 44 freshwater algae (except diatoms and red algae) belonging to classes' cyanophyceae, chlorophyceae, charophyceae and euglenophyceae from Hasina wetland and its surrounding area, Sundar- Haraicha, Morang, Nepal. Samples were collected from Budhi Khola, Khayer Khola and ponds and marshy land in Hasina wetland. In total, the largest family was chlorophyceae represented by 30 taxa and the largest genus was Cosmarium represented by 6 taxa. The study showed that this area is rich in algal diversity.
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Generalić Mekinić, Ivana, Vida Šimat, Nikheel Bhojraj Rathod, Imen Hamed e Martina Čagalj. "Algal Carotenoids: Chemistry, Sources, and Application". Foods 12, n. 14 (20 luglio 2023): 2768. http://dx.doi.org/10.3390/foods12142768.
Testo completoAbstract (sommario):
Recently, the isolation and identification of various biologically active secondary metabolites from algae have been of scientific interest, with particular attention paid to carotenoids, widely distributed in various photosynthetic organisms, including algal species. Carotenoids are among the most important natural pigments, with many health-promoting effects. Since the number of scientific studies on the presence and profile of carotenoids in algae has increased exponentially along with the interest in their potential commercial applications, this review aimed to provide an overview of the current knowledge (from 2015) on carotenoids detected in different algal species (12 microalgae, 21 green algae, 26 brown algae, and 43 red algae) to facilitate the comparison of the results of different studies. In addition to the presence, content, and identification of total and individual carotenoids in various algae, the method of their extraction and the main extraction parameters were also highlighted.
25
Petroll, Romy, Mona Schreiber, Hermann Finke, J. Mark Cock, Sven B. Gould e Stefan A. Rensing. "Signatures of Transcription Factor Evolution and the Secondary Gain of Red Algae Complexity". Genes 12, n. 7 (9 luglio 2021): 1055. http://dx.doi.org/10.3390/genes12071055.
Testo completoAbstract (sommario):
Red algae (Rhodophyta) belong to the superphylum Archaeplastida, and are a species-rich group exhibiting diverse morphologies. Theory has it that the unicellular red algal ancestor went through a phase of genome contraction caused by adaptation to extreme environments. More recently, the classes Porphyridiophyceae, Bangiophyceae, and Florideophyceae experienced genome expansions, coinciding with an increase in morphological complexity. Transcription-associated proteins (TAPs) regulate transcription, show lineage-specific patterns, and are related to organismal complexity. To better understand red algal TAP complexity and evolution, we investigated the TAP family complement of uni- and multi-cellular red algae. We found that the TAP family complement correlates with gain of morphological complexity in the multicellular Bangiophyceae and Florideophyceae, and that abundance of the C2H2 zinc finger transcription factor family may be associated with the acquisition of morphological complexity. An expansion of heat shock transcription factors (HSF) occurred within the unicellular Cyanidiales, potentially as an adaption to extreme environmental conditions.
26
Alghazeer, Rabia, Hesham El Fatah, Salah Azwai, Sana Elghmasi, Maammar Sidati, Ali El Fituri, Ezdehar Althaluti et al. "Nutritional and Nonnutritional Content of Underexploited Edible Seaweeds". Aquaculture Nutrition 2022 (15 ottobre 2022): 1–8. http://dx.doi.org/10.1155/2022/8422414.
Testo completoAbstract (sommario):
Macroalgae are a valuable source of highly bioactive primary and secondary metabolites that may have useful bioapplications. To investigate the nutritional and nonnutritional contents of underexploited edible seaweeds, proximate composition, including protein, fat, ash, vitamins A, C, and E, and niacin, as well as important phytochemicals, including polyphenols, tannins, flavonoids, alkaloids, sterols, saponins, and coumarins, were screened from algal species using spectrophotometric methods. Ash content ranged from 3.15–25.23% for green seaweeds, 5–29.78% for brown algae, and 7–31.15% for red algae. Crude protein content ranged between 5 and 9.8% in Chlorophyta, 5 and 7.4% in Rhodophyta, and between 4.6 and 6.2% in Phaeophyceae. Crude carbohydrate contents ranged from 20 to 42% for the collected seaweeds, where green algae had the highest content (22.5–42%), followed by brown algae (21–29.5%) and red algae (20–29%). Lipid content was found to be low in all the studied taxa at approximately 1–6%, except for Caulerpa prolifera (Chlorophyta), which had a noticeable higher lipid content at 12.41%. These results indicated that Phaeophyceae were enriched with a high phytochemical content, followed by that of Chlorophyta and Rhodophyta. The studied algal species contained a high amount of carbohydrate and protein, indicating that they could be considered as a healthy food source.
27
Titlyanov, Eduard A., Tamara V. Titlyanova, Mutsunori Tokeshi e Xiubao Li. "Inventory and Historical Changes in the Marine Flora of Tomioka Peninsula (Amakusa Island), Japan". Diversity 11, n. 9 (6 settembre 2019): 158. http://dx.doi.org/10.3390/d11090158.
Testo completoAbstract (sommario):
Intensive algal sampling was conducted from 2012 to 2017 in the Tomioka Peninsula, Amakusa-Shimoshima Island (the East China Sea, Japan), yielding a total of 293 benthic macroalgal taxa, of which 63% were red algae, 16% were brown algae, and 19% were green algae. The majority (69%) of species were previously recorded only for the tropics and/or subtropics, whereas 31% of species were recorded for temperate latitudes. Among all species of algae found from 2012 to 2017 in the Tomioka Peninsula, 163 species (56%) were newly identified species for Amakusa-Shimoshima Island, including six taxa, which were recorded in Japan for the first time. Comparison of the current data from the Amakusa-Shimoshima Island with those of nearby tropical regions suggested that the recent marine flora of the Amakusa-Shimoshima Island was more closely affiliated with the flora of a warm-temperate region. Moreover, we found that the benthic flora of the Tomioka Peninsula was significantly changed between the 1950s (Segawa & Yoshida 1961) and 2012–2017. For example, the species diversity was increased by two times, mainly at the expense of red and green algae, and the biogeographic status of the benthic flora was changed from the flora of a cold-temperate region to the flora of a warm-temperate region, which could be attributed to an introduction of red algae from the tropics of South East Asia and widespread opportunistic green algae, as well as the disappearance of cold-water brown algae. Collectively, our data suggested that these changes were driven by the global warming effect on the ocean.
28
Titlyanov, Eduard A., Tamara V. Titlyanova, Xiubao Li, Gayle I. Hansen e Hui Huang. "Seasonal changes in the intertidal algal communities of Sanya Bay (Hainan Island, China)". Journal of the Marine Biological Association of the United Kingdom 94, n. 5 (25 aprile 2014): 879–93. http://dx.doi.org/10.1017/s0025315414000460.
Testo completoAbstract (sommario):
A floristic study of marine macrophytic algae and Cyanobacteria in the splash and intertidal zones at Luhuitou reef, Sanya Bay, Hainan Island, China, was conducted during the rainy and dry seasons of 2008−2012 utilizing 148 of the most common species. Macrophytic algal diversity increased from the splash zone to the low intertidal zone, while cyanobacterial diversity decreased. In the upper and middle intertidal zones, the dominant species (primarily highly productive ephemerals) changed frequently throughout each year. In the low intertidal zone, the dominant species (mainly annual fleshy, foliose and coriaceous forms) also changed. In the dry season, species numbers were 33% higher than in the rainy season. During the rainy season, Cyanobacteria dominated the splash zone, while green and red algae dominated in increasing numbers from the upper to the low intertidal zones. During the dry season the splash zone was devoid of all macrophytic algae, and only one species of Cyanobacteria survived. In the upper intertidal, Cyanobacteria and red algae prevailed, while in the mid and low zones, red and green algae were the most diverse. In spite of heavy pollution in Sanya Bay, there was no evidence of dramatic changes in species numbers or composition, and the marine flora was similar to that of unpolluted regions in the Indo-Pacific.
29
Mišurcová, L., S. Kráčmar, B. Klejdus e J. Vacek. "Nitrogen content, dietary fiber, and digestibility in algal food products". Czech Journal of Food Sciences 28, No. 1 (18 febbraio 2010): 27–35. http://dx.doi.org/10.17221/111/2009-cjfs.
Testo completoAbstract (sommario):
The basic nutritional aspects and parameters of freshwater and marine algal food products are described. Blue-green algae (<I>Spirulina pacifica, S. platensis</I>), green algae (<I>Chlorella pyrenoidosa</I>), red algae (<I>Palmaria palmata, Porphyra tenera</I>), and brown algae (<I>Eisenia bicyclis, Hizikia fusiformis, Laminaria japonica, Undaria pinnatifida</I>) were used for this purpose. The ash content, total nitrogen, dietary fibers, and in vitro digestibility of the above-mentioned algal species were studied. The ash contents amounted to 8–11% (for freshwater) and 9–33% (for marine) of the weights of the algal samples. The total nitrogen contents were analysed using a modified Winkler’s method; in the process, higher nitrogen contents were observed in freshwater algae than in marine ones. For the analysis of dietary fiber contents, the instrument Ankom<sup>220</sup> Fibre Analyser was used. The marine brown algae species were generally assigned higher contents of dietary fiber than the freshwater algal products. The results of the dietary fiber analysis differed with the methodologies used. Pepsin, pancreatin, and a combination of both were applied for the study of <I>in vitro</I> digestibility. Generally, brown algae showed the worst digestibility in comparison with other algal food products.
30
Badger, Murray R., T. John Andrews, S. M. Whitney, Martha Ludwig, David C. Yellowlees, W. Leggat e G. Dean Price. "The diversity and coevolution of Rubisco, plastids, pyrenoids, and chloroplast-based CO2-concentrating mechanisms in algae". Canadian Journal of Botany 76, n. 6 (1 giugno 1998): 1052–71. http://dx.doi.org/10.1139/b98-074.
Testo completoAbstract (sommario):
Algae have adopted two primary strategies to maximize the performance of Rubisco in photosynthetic CO2 fixation. This has included either the development of a CO2-concentrating mechanism (CCM), based at the level of the chloroplast, or the evolution of the kinetic properties of Rubisco. This review examines the potential diversity of both Rubisco and chloroplast-based CCMs across algal divisions, including both green and nongreen algae, and seeks to highlight recent advances in our understanding of the area and future areas for research. Overall, the available data show that Rubisco enzymes from algae have evolved a higher affinity for CO2 when the algae have adopted a strategy for CO2 fixation that does not utilise a CCM. This appears to be true of both Green and Red Form I Rubisco enzymes found in green and nongreen algae, respectively. However, the Red Form I Rubisco enzymes present in nongreen algae appear to have reduced oxygenase potential at air level of O2. This has resulted in a photosynthetic physiology with a reduced potential to be inhibited by O2 and a reduced need to deal with photorespiration. In the limited number of microalgae that have been examined, there is a strong correlation between the existence of a high-affinity CCM physiology and the presence of pyrenoids in all algae, highlighting the potential importance of these chloroplast Rubisco-containing bodies. However, in macroalgae, there is greater diversity in the apparent relationships between pyrenoids and chloroplast features and the CCM physiology that the species shows. There are many examples of microalgae and macroalgae with variations in the presence and absence of pyrenoids as well as single and multiple chloroplasts per cell. This occurs in both green and nongreen algae and should provide ample material for extending studies in this area. Future research into the function of the pyrenoid and other chloroplast features, such as thylakoids, in the operation of a chloroplast-based CCM needs to be addressed in a diverse range of algal species. This should be approached together with assessment of the coevolution of Rubisco, particularly the evolution of Red Form I Rubisco enzymes, which appear to achieve superior kinetic characteristics when compared with the Rubisco of C3 higher plants, which are derived from green algal ancestors.Key words: Rubisco, CO2-concentrating mechanism, carbonic anhydrase, aquatic photosynthesis, algae, pyrenoids, inorganic carbon.
31
Yanshin, Nikolay, Aleksandra Kushnareva, Valeriia Lemesheva, Claudia Birkemeyer e Elena Tarakhovskaya. "Chemical Composition and Potential Practical Application of 15 Red Algal Species from the White Sea Coast (the Arctic Ocean)". Molecules 26, n. 9 (24 aprile 2021): 2489. http://dx.doi.org/10.3390/molecules26092489.
Testo completoAbstract (sommario):
Though numerous valuable compounds from red algae already experience high demand in medicine, nutrition, and different branches of industry, these organisms are still recognized as an underexploited resource. This study provides a comprehensive characterization of the chemical composition of 15 Arctic red algal species from the perspective of their practical relevance in medicine and the food industry. We show that several virtually unstudied species may be regarded as promising sources of different valuable metabolites and minerals. Thus, several filamentous ceramialean algae (Ceramium virgatum, Polysiphonia stricta, Savoiea arctica) had total protein content of 20–32% of dry weight, which is comparable to or higher than that of already commercially exploited species (Palmaria palmata, Porphyra sp.). Moreover, ceramialean algae contained high amounts of pigments, macronutrients, and ascorbic acid. Euthora cristata (Gigartinales) accumulated free essential amino acids, taurine, pantothenic acid, and floridoside. Thalli of P. palmata and C. virgatum contained the highest amounts of the nonproteinogenic amino acid β-alanine (9.1 and 3.2 μM g−1 DW, respectively). Several red algae tend to accumulate heavy metals; although this may limit their application in the food industry, it makes them promising candidates for phytoremediation or the use as bioindicators.
32
Rahiminejad, Amir Hossein, Mehdi Yazdi e Amit Kumar Ghosh. "Paleoecology of Lower Miocene coralline red algae-rich grainstone facies in the Qom Formation (Vartun section, central Iran)". Boletín de la Sociedad Geológica Mexicana 74, n. 2 (30 luglio 2022): A020122. http://dx.doi.org/10.18268/bsgm2022v74n2a020122.
Testo completoAbstract (sommario):
In this paleoecological study we focused on coralline red algae-rich shoal grainstone facies in the Lower Miocene (Aquitanian) carbonates of the Qom Formation in the Vartun section in central Iran. The identified coralline red algae are mainly non-geniculate, although very rare geniculate forms of corallines were also recognized in thin section analysis. The identified algae are represented by Melobesioideae (Lithothamnion cf. valens, Lithothamnion cf. rovereoti, Lithothamnion cf. peleense, and Lithothamnion spp.), Mastophoroideae (Neogoniolithon sp., Spongites spp., and Spongites cf. fruticulosus), Sporolithon spp. (Sporolithon spp. and Sporolithon cf. airoldii), and geniculate coralline (Corallina). The algal taxa mainly display fruticose and lumpy growth forms. The dominance of the former is consistent with high water energy in the identified shoal environment. The presence of Lower Miocene algae indicates that deposition of carbonates took place in warm tropical to subtropical waters in a euphotic marine environment during the Aquitanian. Likewise, high water energy and sediment agitation resulted in taphonomic features such as fragmentation, abrasion, and disarticulation.
33
Shan, Shihan, Xiaoping Wang, Zhuoyun Xu e Mengmeng Tong. "Rapid Algae Identification and Concentration Prediction Based on Discrete Excitation Fluorescence Spectra". Chemosensors 9, n. 10 (18 ottobre 2021): 293. http://dx.doi.org/10.3390/chemosensors9100293.
Testo completoAbstract (sommario):
In this paper, an algal identification and concentration determination method based on discrete excitation fluorescence spectra is proposed for online algae identification and concentration prediction. The discrete excitation fluorescence spectra of eight species of harmful algae from four algal categories were assessed. After determining typical excitation wavelengths according to the distribution of photosynthetic pigments and eliminating strongly correlated wavelengths by applying the hierarchical clustering, seven characteristic excitation wavelengths (405, 435, 470, 490, 535, 555, and 590 nm) were selected. By adding the ratios between feature points (435 and 470 nm, 470 and 490 nm, as well as 535 and 555 nm), standard feature spectra were established for classification. The classification accuracy in pure samples exceeded 95%, and that of dominant algae species in a mixed sample was 77.4%. Prediction of algae concentration was achieved by establishing linear regression models between fluorescence intensity at seven characteristic excitation wavelengths and concentrations. All models performed better at low concentrations, not exceeding the threshold concentration of red tide algae outbreak, which provides a proximate cell density of dominant algal species.
34
Sarkar, Suman, Amit K. Ghosh e Madhav Kumar. "Recognition of algal rich facies from the Umlatdoh Limestone of Shella Formation, Jaintia Group, Meghalaya". Journal of Palaeosciences 60, n. (1-2) (31 dicembre 2011): 315–21. http://dx.doi.org/10.54991/jop.2011.178.
Testo completoAbstract (sommario):
The carbonate rocks of the Shella Formation (Middle Eocene) belonging to the Jaintia Group in the Jaintia Hills of Meghalaya are represented by two sandstone units in alternation with three limestone units, viz. Lakadong Limestone, Umlatdoh Limestone and Prang Limestone respectively in chronological order. Umlatdoh Limestone, the middle limestone unit of Shella Formation is conformably underlain by the Lakadong Sandstone and overlain by Narpuh Sandstone. Samples from the Umlatdoh Limestone were collected from the outcrop on the Jowai-Badarpur Road, about 1 km southwest of Lumshnong. Calcareous algae have been recovered from four samples and two distinct facies have been recognized. One of the facies is dominated by non-geniculate coralline red algae and benthic foraminifera. The non-geniculate corallines are represented by Lithothamnion and Mesophyllum (Family Hapalidiaceae), Lithoporella (Family Corallinaceae) and Sporolithon (Family Sporolithaceae). The other facies is rich in calcareous green algae along with benthic foraminifera. The green algal genera belong to families Dasycladaceae, Udoteaceae and Halimedaceae. Previously, a green algal assemblage was recorded from the Umlatdoh Limestone Member of Shella Formation exposed in the low lying hills between Sutnga and Litang valleys of Jaintia Hills. However, this is the first report on the occurrence of non-geniculate coralline red algae from the Umlatdoh Limestone Member of the Shella Formation. Based on the algal-foraminiferal assemblages, interpretation has been made on the palaeoenvironment and palaeobathymetry.
35
Shen, Yuefeng, e Fritz Neuweiler. "Taphocoenoses and diversification patterns of calcimicrobes and calcareous algae, Ordovician, Tarim Basin, China". Canadian Journal of Earth Sciences 53, n. 7 (luglio 2016): 702–11. http://dx.doi.org/10.1139/cjes-2015-0173.
Testo completoAbstract (sommario):
Despite the crucial role of epibenthic primary producers (cyanobacteria, green and red algae), no diversity curves for calcimicrobes and calcareous algae are available to assess the pyramiding paleoecology characterizing the Ordovician biodiversification episode. A total of 24 taxa of calcimicrobes and calcareous algae are identified from a Dapingian to lower Katian succession of carbonate sedimentary rocks exposed at the Leyayilitag ridge, Bachu Uplift, Tarim Basin, northwest China. Calcimicrobes (14 taxa), Dasycladales (seven taxa), Bryopsidales (one taxon), and Cyclocrinales (two taxa) contribute to five distinct taphocoenoses characterizing a suite of carbonate mounds. In stratigraphic order, these are calathid sponge mounds, algal calcimicrobial mounds, algal mounds, algal reefs, and calcimicrobial mounds. Within the lower Katian Belodina confluens Zone, the diversity increases substantially from around 5 to more than 20 taxa per 2 Ma. This increase in diversity is based on new calcimicrobes (Bija, Ortonella, Garwoodia, Hedstroemia, Rothpletzella, Phacelophyton, Rauserina) and the diversification of Dasycladales and Cyclocrinales. By comparison, the global diversity of calcimicrobes and calcareous algae (derived from literature data) started to increase earlier, namely within the late Darriwilian Pygodus serra Zone (offset of about 4 Ma). This offset might be due to the peculiar lithology of the Sandbian Tumuxiuke Formation (condensed section of red nodular limestones bounded by disconformities). However, a similar temporal offset is recorded for calathid sponge mounds; therefore, the Tarim tectonic microplate (Tarim Block) might display an endemic–anachronistic character. The diversity curves of Ordovician benthic primary producers (calcimicrobes, calcareous algae) are similar to those recorded by some fossil groups, in particular eleutherozoan echinoderms.
36
Suryandari, Retno. "Checklist of Macroalgae at Krakal and Drini Beach, Gunungkidul". Proceeding International Conference on Science and Engineering 1 (31 ottobre 2017): 31–38. http://dx.doi.org/10.14421/icse.v1.266.
Testo completoAbstract (sommario):
Macroalgae are multicellular plants that do not produce seeds or flowers. All macroalgae are multicellular and do not have a specialized body structure and do not have reproductive mechanism like terrestrial plants. Macroalgae is divided into 3 groups namely Chlorophyta (green algae), Rhodophyta (red algae), and Phaeophyceae (brown algae). Green algae and red algae belong to the Plantae kingdom with green algae (Chlorophyta) and included in the Subkingdom Viridiplantae and red algae (Rhodophyta) into the Biliphyta subkingdom. Brown algae (Phaeophyta) belong to the Chromista kingdom. Based on the research, macroalgae found in Drini and Krakal Gunungkidul are green algae, red algae and brown algae. Green algae found and identified are Anadyomene plicata C. Agardh, Chaetomorpha antennina (Bory) Kṻtzing, Chaetomorpha linum (O.F. Mṻller) Kṻtzing, Boergesenia forbesii (Hardvey) Feldmann, Cladophoropsis herpestica (Montagne) M. Howe, Boodlea composita (Harvey) F. Brand, Caulerpa peltata J.V. Lamoroux, Enteromorpha intestinalis (Linnaeus) Nees, Ulva lactuca Linnaeus. Red algae species found and successfully identified are Acrocystis nana Zanardini, Acanthophora spicifera (M. Vahl) Børgesen, Laurencia papilosa (C. Agardh) Greville, Actinotrichia fragilis (Forsskål) Børgesen, Galaxaura rugosa (J. Ellis & Solander) J.V. Lamoroux, Amphiora anceps (Lamark) Decaisne, Gelidiela acerosa (Forsskål) Feldmann & Hamel, Gracilaria canaliculata Sonder, Gelidiopsis intricata (C.Agardh) Vickers. Brown algae species found and identified are Lobophora variegata (J.V.Lamouroux) Womersley ex E.C.Oliveira, Padina minor Yamada, Sargassum crassifolium J. Agardh, Turbinaria ornata (Turner) J. Agardh. The species that classified as a new record in Indonesia are Cladophoropsis herpestica (Montagne) M. Howe and Gracilaria spinulosa (Okamura) Chang & B.M.Xia.
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Refilda, Edison Munaf, Rahmiana Zein, Abdi Dharma, Indrawati, Lee Wah Lim e Toyohide Takeuchi. "OPTIMATION STUDY OF CARRAGEENAN EXTRACTION FROM RED ALGAE (Eucheuma cottonii)". Jurnal Riset Kimia 2, n. 2 (12 febbraio 2015): 120. http://dx.doi.org/10.25077/jrk.v2i2.151.
Testo completoAbstract (sommario):
ABSTRACT Carrageenan is a general name for polysacharides, it is made up of sodium, potassium, magnesium, and calcium sulphat esters of galactose and 3.6-anhydrogalactose units. Research about parameters influencing extraction process of carrageenan from red algae (Eucheuma cottonii) has been studied. The parameters were particle size of red algae, pH of NaOH solution, heating time and heating temperature. About 64.30% of carrageenan was extracted from red algae (Eucheuma cottonii) under optimum condition, 425 µm particle size of red algae, solution pH 8.5, heating time 18 h, and heating temperature 95°C. The FTIR spectra of extracted carrageenan showed the same spectra as the pure carrageenan. Keywords : carrageenan, red algae (Eucheuma cottonii), and extraction
38
Dorrell, Richard G., e Alison G. Smith. "Do Red and Green Make Brown?: Perspectives on Plastid Acquisitions within Chromalveolates". Eukaryotic Cell 10, n. 7 (27 maggio 2011): 856–68. http://dx.doi.org/10.1128/ec.00326-10.
Testo completoAbstract (sommario):
ABSTRACT The chromalveolate “supergroup” is of key interest in contemporary phycology, as it contains the overwhelming majority of extant algal species, including several phyla of key importance to oceanic net primary productivity such as diatoms, kelps, and dinoflagellates. There is also intense current interest in the exploitation of these algae for industrial purposes, such as biodiesel production. However, the evolution of the constituent species, and in particular the origin and radiation of the chloroplast genomes, remains poorly understood. In this review, we discuss current theories of the origins of the extant red alga-derived chloroplast lineages in the chromalveolates and the potential ramifications of the recent discovery of large numbers of green algal genes in chromalveolate genomes. We consider that the best explanation for this is that chromalveolates historically possessed a cryptic green algal endosymbiont that was subsequently replaced by a red algal chloroplast. We consider how changing selective pressures acting on ancient chromalveolate lineages may have selectively favored the serial endosymbioses of green and red algae and whether a complex endosymbiotic history facilitated the rise of chromalveolates to their current position of ecological prominence.
39
Eloranta, Pertti. "Freshwater red algae in Finland". Plant and Fungal Systematics 64, n. 1 (1 luglio 2019): 41–51. http://dx.doi.org/10.2478/pfs-2019-0006.
Testo completoAbstract (sommario):
AbstractThere were only less than sixty records of freshwater red algae in Finland until the 1980s, when the author began sampling the running waters of southern and central Finland; 516 new records were made in 1984–2011. More intensive research began in 2012, with a few field teams working at first in Central Finland Province and then covering the whole country. The project continued until 2018. During these studies approximately 3400 new locations were investigated and 3641 new records of 29 taxa were made. Since 2013, 12 ecological variables have also been measured or estimated. The share of positive records from the studied locations varied from 49% to 86% (avg. 72%), being highest in Lapland (85.5%). The most frequent taxa were Batrachospermum gelatinosum (36.5%), Audouinella hermannii (14.5%), Sheathia arcuata (9.3%), Sirodotia suecica (8.4%), Audouinella chalybea (4.7%), Lemanea fluviatilis (3.8%) and Lemanea fucina (2.8%). Batrachospermum elegans, Kumanoa virgatodecaisneana and Lemanea mamillosa occurred in southwestern Finland in waters with higher conductivity, whereas Batrachospermum turfosum and Virescentia vogesiaca were typical taxa of acidic and soft water. Batrachospermum sporulans and Lemanea condensata occurred only in northern Finland. Some records did not fit the recent morphological keys and should be analysed using molecular methods.
40
Quarmby, Lynne M. "When green algae turn red". Environmental Microbiology 19, n. 2 (27 gennaio 2017): 415–16. http://dx.doi.org/10.1111/1462-2920.13620.
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Gabrielson, Paul W., David Garbary e Max H. Hommersand. "Systematics of red algae (Rhodophyta)". Critical Reviews in Plant Sciences 3, n. 4 (gennaio 1986): 325–66. http://dx.doi.org/10.1080/07352688609382215.
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Holst, P. B., S. E. Nielsen, U. Anthoni, K. S. Bisht, C. Christophersen, S. Gupta, V. S. Parmar, P. H. Nielsen, D. B. Sahoo e A. Singh. "Isethionate in certain red algae". Journal of Applied Phycology 6, n. 5-6 (dicembre 1994): 443–46. http://dx.doi.org/10.1007/bf02182396.
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Kraft, Gerald T. "Biology of the Red Algae". Phycologia 31, n. 3-4 (maggio 1992): 368–71. http://dx.doi.org/10.2216/i0031-8884-31-3-4-368.1.
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ISHIDA, YUZABURO. "Phagocytosis of red tide algae." Kagaku To Seibutsu 24, n. 7 (1986): 475–77. http://dx.doi.org/10.1271/kagakutoseibutsu1962.24.475.
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Murray, Steven N. "Biology of the Red Algae". Journal of Experimental Marine Biology and Ecology 169, n. 2 (luglio 1993): 274–77. http://dx.doi.org/10.1016/0022-0981(93)90198-w.
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46
Vinitnantharat, S., W. Chartthe e A. Pinisakul. "Toxicity of reactive red 141 and basic red 14 to algae and waterfleas". Water Science and Technology 58, n. 6 (1 ottobre 2008): 1193–98. http://dx.doi.org/10.2166/wst.2008.476.
Testo completoAbstract (sommario):
Textile wastewater normally has a visible color although it has low concentration. This may affect the aquatic ecosystem. Two dyestuffs, Reactive Red 141 (RR141) and Basic Red14 (BR14) were used as compound models. RR 141 is an anionic dye which has a big molecule whereas BR 14 is a cationic dye and has a small molecule. The target organisms for toxicity test were green algae (Chlorella sp.) and waterfleas (Moina macrocopa). The effect of humic acid on the toxicity of dyestuffs to test organisms was also investigated. From the observation of cell counts, Chlorophyll a and dry weight of algae in the dye solutions for 4 days, it was found that all parameters increased as times increased. This revealed that algae could utilize dyestuffs as a carbon source. However, BR14 gave higher absorbance than RR141 at the wavelength of 430 nm which competed to the Chlorophyll a for algal photosynthesis. This resulted in the 96-h EC50 of BR14 and RR141 to Chlorella sp. were 10.88 and 95.55 mg/L, respectively. As for dye toxicity to waterfleas, the 48-h LC50 of BR14 and RR141 to waterfleas were 4.91 and 18.26 mg/L, respectively. The high toxicity of BR14 to waterfleas related to the small molecule of dye could pass into the cell and was absorbed by organelles of waterfleas. Toxicity of BR14 in humic acid solution to Chlorella sp. showed less toxic than RR141 in humic acid solution. This dues to the negative charge of humic acid could bound with a positive charge of BR14, resulted in low amount of BR14 remaining in the bulk solution. The toxicity of BR14 and RR141 in humic acid solution to waterfleas was increased as humic acid increased. Hence, the proper treatment of textile wastewater to yield low concentration of dyes in the effluent before discharging to the natural water is needed.
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Salomaki, Eric D., e Christopher E. Lane. "Are all red algal parasites cut from the same cloth?" Acta Societatis Botanicorum Poloniae 83, n. 4 (2014): 369–75. http://dx.doi.org/10.5586/asbp.2014.047.
Testo completoAbstract (sommario):
Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta), and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae.
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Ramkumar, Ashwini, e Sridar Jayavel. "Isolation of Fatty Acid Constituents from Ulva Fasciata and its Anticancer Activity on HeLa Cells". Shanlax International Journal of Arts, Science and Humanities 10, n. 2 (1 ottobre 2022): 28–37. http://dx.doi.org/10.34293/sijash.v10i2.4999.
Testo completoAbstract (sommario):
Macroalgae are found as a great source of biologically active compounds important in pharmaceutical industry. In this study, 8 algal samples namely Ulvafasciata (Green algae), Padinagymnosphora, Sargassamwightii, and Turbinariaornate (brown algae), Gracilariacorticata, Halimedamacrolopa, Halymeniadilatata, and Gracilariacrassa (red algae) were collected and identified its fatty acid compositions. U. fasciatawhich showed high fatty acid constituents was further analysed for its anticancer activity against Hela cells by MTT assay and AO/EtBr staining. The results confirmed that U. fasciata could inhibit the Hela cells by cytotoxic activity and by inducing apoptosis and thus could be used as apontential source in treating cancers.
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Liu, Chenlin, e Xiuliang Wang. "Superoxide dismutase and ascorbate peroxidase genes in Antarctic endemic brown alga Ascoseira mirabilis (Ascoseirales, Phaeophyceae): data mining of a de novo transcriptome". Botanica Marina 63, n. 6 (16 dicembre 2020): 541–49. http://dx.doi.org/10.1515/bot-2020-0025.
Testo completoAbstract (sommario):
AbstractThe Antarctic endemic brown alga Ascoseira mirabilis is physically and physiologically well adapted to the extreme polar environment. To better understand the molecular strategies associated with stress adaptation, the transcriptome of A. mirabilis was sequenced, and its antioxidant enzyme genes were identified and compared with other algae. A total of 126,576 unigenes with a mean length of 734 bp and N50 of 1174 bp was assembled from the transcriptome data. Phylogenetic analysis revealed that dramatic evolutionary changes had occurred in the brown algal superoxide dismutases (SODs) and class I peroxidases that were not consistent with the phylogeny of the species. Fe/Mn SODs are more prevalent in brown algae than in red and green algae. Two additional Fe-SODs in A. mirabilis were phylogenetically closely related to those of green algae, but not to those in other brown algae. We also identified three A. mirabilis ascorbate peroxidase (APx) genes that had a different origin from other brown algal APxs. The SOD and APx genes specifically identified in A. mirabilis will be crucial for understanding the evolution of the algal antioxidant enzymes that contribute to ecological success under extreme environmental conditions in the Antarctic region.
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Kraft, Gerald T. "Algae of Australia: Marine benthic algae of north-western Australia 2. Red algae". Phycologia 58, n. 2 (6 febbraio 2019): 225–27. http://dx.doi.org/10.1080/00318884.2018.1551025.
Testo completo