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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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Ginting, Elvy Like, Liviani Rangian, Letha L. Wantania e Stenly Wullur. "Isolation of Symbiotic Bacteria with Red Algae from Tongkaina Waters, North Sulawesi". JURNAL ILMIAH PLATAX 7, n. 2 (7 luglio 2019): 395. http://dx.doi.org/10.35800/jip.7.2.2019.23728.
Testo completoAbstract (sommario):
This study aims to isolate symbiotic bacteria with red algae from the waters of Tongkaina, North Sulawesi. The red algae taken were red algae that are similar to the genus Portieria and Gracilaria. Bacteria were cultured and isolated using Nutrient Agar (NA) + sea water. Before bacteria from red algae samples were cultured, each sample of red algae was crushed, homogenized and diluted. The results of this study, 5 bacterial isolates were successfully isolated from red algae similar to Portieria sp. and 5 bacterial isolates from red algae similar to Gracilaria sp. Each bacterial isolate has different morphological characteristics such as shape, colour, elevation, and edges. Of the 10 bacterial isolates, 3 bacterial cells are gram-positive cocci (round), and 7 of them are gram-negative bacilli (rod).Keywords: Red algae, bacteria, isolation, symbionts ABSTRAKTujuan dari penelitian ini adalah untuk mengisolasi bakteri simbion dengan alga merah dari perairan Tongkaina, Sulawesi Utara. Alga merah yang diambil adalah alga merah yang mirip dengan genus Portieria dan Gracilaria. Bakteri ditumbuhkan dan diisolasi menggunakan media Nutrien Agar (NA) + air laut. Sebelum bakteri dari sampel alga merah ditumbuhkan, masing-masing sampel alga merah digerus, dihomogeniasi dan diencerkan. Hasil penelitian ini, 5 isolat bakteri berhasil diisolasi dari alga merah mirip Portieria sp. dan 5 isolat bakteri dari alga merah mirip Gracilaria sp. Masing-masing isolat bakteri memiliki karakteristik morfologi yang berbeda seperti bentuk, warna, elevasi, dan tepian. Dari 10 isolat bakteri tersebut, 3 sel bakteri bersifat gram positif dengan bentuk bulat, dan 7 diantaranya bersifat gram negatif dengan bentuk batang.Kata kunci: Alga merah, bakteri, isolasi, simbion
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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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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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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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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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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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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.
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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.
Testo completo
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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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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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Rico Taareluan, Rico, Letha L. Wantania, Elvy L. Ginting, Remy E. P. Mangindaan, Deislie R. H. Kumampung, Reni Lusia Kreckhoff e Stnly Wullur. "AMPLIFIKASI GEN 16S-rRNA BAKTERI EPIFIT PADA ALGA MERAH Kappaphycus alvarezii". JURNAL PESISIR DAN LAUT TROPIS 8, n. 1 (15 gennaio 2020): 116. http://dx.doi.org/10.35800/jplt.8.1.2020.27696.
Testo completoAbstract (sommario):
Bacteria are microscopic organism found living in marine algae. So far, species of bacteria in marine algae are not well known. In this study, epiphytic bacteria in algal species of Kappaphycus alvarezii (red algae) were isolated to amplify their 16S-rRNA gene. Sample K.alvarezii was collected from the island of Nain. The isolated epiphytic bacteria from the red algae K.alvarezii were grown in Nutrient Broth (NB) media. DNA extraction was carried out using InnuPREP DNA Mini Kit. 16SrRNA genes was performed using primer pair of 8F and 1492R. Two different character of epiphytic bacteria were successfully isolated from K. alvarezii. 16S-rRNA genes from the two isolates was successfully amplified, indicated by the presence of DNA band in each sample gel electrophoreses at around 1500 bp.Keywords : Amplification, 16S-rRNA Genes, Kappapchycus alvarezii, Bacterial, Epiphytic Abstrak Bakteri adalah organisme mikroskopis yang ditemukan hidup di alga laut. Sejauh ini, spesies bakteri di alga laut belum dikenal. Dalam penelitian ini, bakteri epifit pada spesies alga Kappaphycus alvarezii (alga merah) diisolasi untuk memperkuat gen 16S-rRNA mereka. Sampel K.alvarezii dikumpulkan dari pulau Nain. Bakteri epifit terisolasi dari alga merah K.alvarezii ditanam dalam media Nutrient Broth (NB). Ekstraksi DNA dilakukan dengan menggunakan InnuPREP DNA Mini Kit. Gen 16S-rRNA dilakukan dengan menggunakan pasangan primer 8F dan 1492R. Dua karakter bakteri epifit yang berbeda berhasil diisolasi dari K. alvarezii. Gen 16S-rRNA dari dua isolat berhasil diamplifikasi, ditunjukkan oleh adanya pita DNA pada setiap sampel gel elektroforesis sekitar 1500 bp. Kata Kunci: Amplifikasi, gen 16S-rRNA, Kappapycus alvarezii, Bakteri, Epifit
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Hsieh, Yves, e Philip Harris. "Xylans of Red and Green Algae: What Is Known about Their Structures and How They Are Synthesised?" Polymers 11, n. 2 (18 febbraio 2019): 354. http://dx.doi.org/10.3390/polym11020354.
Testo completoAbstract (sommario):
Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced orders of charophyte green algae. Small proportions of 1,4-β-d-xylans have also been found in the cell walls of some chlorophyte green algae and red algae but have not been well characterised. 1,3-β-d-Xylans occur as triple helices in microfibrils in the cell walls of chlorophyte algae in the order Bryopsidales and of red algae in the order Bangiales. 1,3;1,4-β-d-Xylans occur in the cell wall matrix of red algae in the orders Palmariales and Nemaliales. In the angiosperm Arabidopsis thaliana, the gene IRX10 encodes a xylan 1,4-β-d-xylosyltranferase (xylan synthase), and, when heterologously expressed, this protein catalysed the production of the backbone of 1,4-β-d-xylans. An orthologous gene from the charophyte green alga Klebsormidium flaccidum, when heterologously expressed, produced a similar protein that was also able to catalyse the production of the backbone of 1,4-β-d-xylans. Indeed, it is considered that land plant xylans evolved from xylans in ancestral charophyte green algae. However, nothing is known about the biosynthesis of the different xylans found in chlorophyte green algae and red algae. There is, thus, an urgent need to identify the genes and enzymes involved.
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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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Zemke-White, L. W., e E. L. Beatson. "Algal community composition within territories of the damselfish Stegastes nigricans (Pomacentridae, Labroidei) in Fiji and the Cook Islands". South Pacific Journal of Natural and Applied Sciences 23, n. 1 (2005): 43. http://dx.doi.org/10.1071/sp05008.
Testo completoAbstract (sommario):
The species composition of algal assemblages inside territories of the damselfish Stegastes nigricans was examined from Nananu-i-ra Island, Fiji and Rarotonga, Cook Islands. A total of 32 algal species were identified, the majority of them Rhodophytes (24 species). Seven species were unique to Rarotonga, six were unique to Fiji, with the remaining 19 species recorded at both locations. The biodiversity of territories was similar at both locations. The red alga, Herposiphonia secunda, was the most abundant species found, comprising 40.33% � 3.51SE and 33.94% � 3.58SE from Rarotonga and Fiji respectively. Gelidiopsis intricata, Polysiphonia sp., Aglaothamnion cordatum, and various Cyanophytes were also abundant at both locations. As a group, filamentous algae accounted for 70.35% of the algae found within the territories at all sites. We suggest that if S. nigricans are actively weeding their territories, they are selecting filamentous algae, and particularly Herposiphonia sp. and Polysiphonia sp.
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Grotti, Marco, Francesco Soggia, Cristina Lagomarsino, Walter Goessler e Kevin A. Francesconi. "Arsenobetaine is a significant arsenical constituent of the red Antarctic alga Phyllophora antarctica". Environmental Chemistry 5, n. 3 (2008): 171. http://dx.doi.org/10.1071/en08025.
Testo completoAbstract (sommario):
Environmental context. Although arsenic occurs in marine animals at high concentrations, the pathways by which it is biotransformed and accumulated remain largely unknown. The observation that some species of algae can contain significant concentrations of arsenobetaine, a major marine arsenic species, is relevant to explanations of the source of this compound to marine animals and its transport through the marine food web. Abstract. Significant amounts of arsenobetaine (up to 0.80 μg As g–1 dry mass, representing 17% of the extractable arsenic) were found in the extracts of all four samples of the red alga Phyllophora antarctica collected from two sites in Antarctica (Terra Nova Bay and Cape Evans). The assignment was made with high performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC-ICPMS) based on exact cochromatography with a standard compound with two chromatographic systems (cation-exchange and ion-pairing reversed-phase), each run under two sets of mobile phase conditions. Particular care was taken during sample preparation to ensure that the arsenobetaine was of algal origin and did not result from epiphytes associated with the alga. Another red alga, Iridaea cordata, collected from Terra Nova Bay, did not contain detectable concentrations of arsenobetaine. For both algal species, the majority of the extractable arsenic was present as arsenosugars. Confirmation that marine algae can contain significant amounts of arsenobetaine allows a simpler explanation for the widespread occurrence of this arsenical in marine animals.
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Moniung, Prisilia, Marina Singkoh e Regina Butarbutar. "Potensi Alga Halymenia durvillei Sebagai Sumber Antioksidan Alami". JURNAL BIOS LOGOS 12, n. 1 (11 aprile 2022): 39. http://dx.doi.org/10.35799/jbl.v12i1.36721.
Testo completoAbstract (sommario):
Red algae have the ability to produce secondary metabolites which are bioactive compounds. The content of secondary metabolites from red algae can be determined by an approach method that can provide information on the presence of secondary metabolites. The purpose of this study was to identify bioactive compounds, as well as to analyze the natural antioxidant activity of H. durvillei algae. Extracts were made by maceration method using 96% ethanol. Antioxidant activity test using DPPH method. Algae extract H. durvillei contains compounds of alkaloids, tannins, saponins and phenols which have antioxidant activity that can counteract the formation of free radicals. The results of antioxidant tests conducted using UV-Vis spectrophotometry on the ethanolic extract of H. durvillei algae showed an IC50 value of 101.22 ppm. Keywords: Red Algae (H. durvillei); Bioactive Compounds; Natural Antioxidants ABSTRAKAlga merah memiliki kemampuan untuk memproduksi metabolit sekunder yang bersifat sebagai senyawa bioaktif. Kandungan senyawa metabolit sekunder dari alga merah dapat diketahui dengan suatu metode pendekatan yang dapat memberikan informasi adanya senyawa metabolit sekunder. Tujuan penelitian ini untuk mengidentifikasi senyawa bioaktif, serta menganalisis aktivitas antioksidan alami yang terdapat pada alga H. durvillei. Pembuatan ekstrak dilakukan dengan metode maserasi menggunakan etanol 96%. Uji aktivitas antioksidan menggunakan metode DPPH. Ekstrak Alga H. durvillei memiliki kandungan senyawa alkaloid, tanin, saponin dan fenol yang memiliki aktivitas antioksidan yang dapat menangkal terbentuknya radikal bebas.Hasil uji antioksidan yang dilakukan menggunakan spektrofotometri UV-Vis pada ekstrak etanol alga H. durvillei menunjukkan nilai IC50 sebesar 101.22 ppm. Kata Kunci: Alga Merah (H. durvillei); Senyawa Bioaktif; Antioksidan Alami
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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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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.
Testo completo
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Han, Narae, Jiwoong Wi, Sungoh Im, Ka-Min Lim, Hun-Dong Lee, Won-Joong Jeong, Geun-Joong Kim et al. "Downregulation of PyHRG1, encoding a novel secretory protein in the red alga Pyropia yezoensis, enhances heat tolerance". Algae 36, n. 3 (15 settembre 2021): 207–17. http://dx.doi.org/10.4490/algae.2021.36.8.26.
Testo completoAbstract (sommario):
An increase in seawater temperature owing to global warming is expected to substantially limit the growth of marine algae, including Pyropia yezoensis, a commercially valuable red alga. To improve our knowledge of the genes involved in the acquisition of heat tolerance in P. yezoensis, transcriptomes sequences were obtained from both the wild-type SG104 P. yezoensis and heat-tolerant mutant Gy500. We selected 1,251 differentially expressed genes that were up- or downregulated in response to the heat stress condition and in the heat-tolerant mutant Gy500, based on fragment per million reads expression values. Among them, PyHRG1 was downregulated under heat stress in SG104 and expressed at a low level in Gy500. PyHRG1 encodes a secretory protein of 26.5 kDa. PyHRG1 shows no significant sequence homology with any known genes deposited in public databases to date. However, PyHRG1 homologs were found in other red algae, including other Pyropia species. When PyHRG1 was introduced into the single-cell green alga Chlamydomonas reinhardtii, transformed cells overexpressing PyHRG1 showed severely retarded growth. These results demonstrate that PyHRG1 encodes a novel red algae-specific protein and plays a role in heat tolerance in algae. The transcriptome sequences obtained in this study, which include PyHRG1, will facilitate future studies to understand the molecular mechanisms involved in heat tolerance in red algae.
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Broadwater, Sharon, Joe Scott, Dawn Field, Bill Saunders e Jewel Thomas. "An ultrastructural study of cell division in the coralline red alga Bossiella orbigniana". Canadian Journal of Botany 71, n. 3 (1 marzo 1993): 434–46. http://dx.doi.org/10.1139/b93-048.
Testo completoAbstract (sommario):
This investigation of Bossiella orbigniana (Decaisne) Silva ssp. orbigniana represents the first ultrastructural account of cell division in the order Corallinales. The mitotic process in this alga is differentiated from that of other red algae by a combination of characters. During prometaphase–metaphase the division poles contain unusual membrane arrangements including quantities of smooth-surfaced membranes and elongate extensions of perinuclear rough ER. At anaphase extensive remnants of nucleolar material attach to the chromosomes, trailing them to the poles. After telophase, the distal nucleus continues to move toward the apex resulting in much greater nuclear segregation than accomplished by anaphase alone. Cytokinesis is temporally displaced from mitosis and displaced distally from the metaphase plate. A reevaluation of ultrastructural patterns of red algal cell division suggests that there are two basic types of mitosis, the polar gap type and the polar fenestrations type to which B. orbigniana belongs. These two types are differentiated by a number of characters with the most important being the configuration of the prometaphase–metaphase polar region and spindle origin. Key words: Bossiella, cell division, Corallinales, mitosis, phylogeny, red algae.
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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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Singkoh, Marina, Desy Mantiri, Cyska Lumenta e Hengky Manoppo. "Identifikasi Senyawa Bioaktif Alga Merah Halymenia durvillei (Identification Bioactive Compounds of Algae Halymenia durvillei)". JURNAL BIOS LOGOS 9, n. 1 (28 febbraio 2019): 21. http://dx.doi.org/10.35799/jbl.9.1.2019.23419.
Testo completoAbstract (sommario):
Identifikasi Senyawa Bioaktif Alga Merah Halymenia durvillei(Identification Bioactive Compounds of Algae Halymenia durvillei) Marina Flora Oktavine Singkohˡ)*, Desy Maria Helena Mantiri ²) Cyska Lumenta²), Henky Manoppo²)1) Program Studi Biologi FMIPA Universitas Sam Ratulangi, Manado 951152) Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi, Manado *Email korespondensi: marinasingkoh16@gmail.com Diterima 17 Februari 2019, diterima untuk dipublikasikan 28 Februari 2019 Abstrak Alga merah memiliki kemampuan untuk memproduksi metabolit sekunder yang bersifat sebagai senyawa bioaktif. Penelitian ini bertujuan untuk mengidentifikasi senyawa bioaktif pada alga merah Halymenia durvillaei. yang diambil dari pesisir Pantai Desa Rendingan, Kecamatan Tabukan Kepulauan Sangihe, Sulawesi Utara dengan metode skrining Fitokimia. Hasil penelitian menunjukan bahwa alga merah Halymenia durvillaei mengandung senyawa-senyawa bioaktif. Berdasarkan hasil penelitian skrining fitokimia dapat disimpulkan bahwa ekstrak etanol Halymenia durvillaei mengandung senyawa bioaktif alkaloid, fenol, saponin, tanin, dan steroid.Kata Kunci: Halymenia durvillaei, senyawa bioaktif, fitokimia Abstract Red algae have the ability to produce secondary metabolites that are bioactive compounds. This study aims to identify bioactive compounds in Halymenia durvillaei red algae taken from the coast of Rendingan Village Beach, Tabukan District, Sangihe Islands, North Sulawesi with the phytochemical screening method. The results showed that Halymenia durvillaei red algae contained bioactive alkaloid compounds. Based on the results of the phytochemical screening study it can be concluded that the Halymenia durvillaei ethanol extract contains bioactive alkaloid compounds, phenols, saponins, tannins, and steroids.Keywords: Halymenia durvillaei, bioactive compounds, phytochemicals
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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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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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S, Satya Lakshmi. "DETERMINATION OF BIOLOGICAL ACTIVITIES OF THREE MARINE ALGAE COLLECTED FROM VISAKHAPATNAM COAST". Asian Journal of Pharmaceutical and Clinical Research 10, n. 12 (1 dicembre 2017): 274. http://dx.doi.org/10.22159/ajpcr.2017.v10i12.20857.
Testo completoAbstract (sommario):
Objective: Determination of biological activities of marine algae collected from the Visakhapatnam coastal region.Methods: Antibacterial activity of algal extracts determined by the well diffusion method, antioxidant activity was determined by reducing power (RP) method and 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging method finally anti-inflammatory activity was determined by human red blood cell stabilization method and egg albumin method.Results: Methanolic extracts of three algae have potential inhibition activity against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. Green alga Enteromorpha compressa has better antioxidant activity compared to the Gracilaria arcuata and Ulva fasciata when tested in RP and DPPH method. U. fasciata found good anti-inflammatory activity among the selected three algae.Conclusion: The three tested algae exhibited significant antibacterial and antioxidant activity compared to anti-inflammatory activity. These bioactive compounds containing macroalgae may find their commercial potential in medicine, food, and cosmetic industry
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Keeling, Patrick J. "The endosymbiotic origin, diversification and fate of plastids". Philosophical Transactions of the Royal Society B: Biological Sciences 365, n. 1541 (12 marzo 2010): 729–48. http://dx.doi.org/10.1098/rstb.2009.0103.
Testo completoAbstract (sommario):
Plastids and mitochondria each arose from a single endosymbiotic event and share many similarities in how they were reduced and integrated with their host. However, the subsequent evolution of the two organelles could hardly be more different: mitochondria are a stable fixture of eukaryotic cells that are neither lost nor shuffled between lineages, whereas plastid evolution has been a complex mix of movement, loss and replacement. Molecular data from the past decade have substantially untangled this complex history, and we now know that plastids are derived from a single endosymbiotic event in the ancestor of glaucophytes, red algae and green algae (including plants). The plastids of both red algae and green algae were subsequently transferred to other lineages by secondary endosymbiosis. Green algal plastids were taken up by euglenids and chlorarachniophytes, as well as one small group of dinoflagellates. Red algae appear to have been taken up only once, giving rise to a diverse group called chromalveolates. Additional layers of complexity come from plastid loss, which has happened at least once and probably many times, and replacement. Plastid loss is difficult to prove, and cryptic, non-photosynthetic plastids are being found in many non-photosynthetic lineages. In other cases, photosynthetic lineages are now understood to have evolved from ancestors with a plastid of different origin, so an ancestral plastid has been replaced with a new one. Such replacement has taken place in several dinoflagellates (by tertiary endosymbiosis with other chromalveolates or serial secondary endosymbiosis with a green alga), and apparently also in two rhizarian lineages: chlorarachniophytes and Paulinella (which appear to have evolved from chromalveolate ancestors). The many twists and turns of plastid evolution each represent major evolutionary transitions, and each offers a glimpse into how genomes evolve and how cells integrate through gene transfers and protein trafficking.
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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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Sukiman, Mursal Ghazali, Hijjatul Husna,. "Diversitas dan Karakteristik Alga Merah (Rhodophyta) pada Akar Mangrove di Teluk Serewe Kabupaten Lombok Timur". Jurnal Biologi Tropis 18, n. 1 (28 giugno 2018): 80. http://dx.doi.org/10.29303/jbt.v18i1.732.
Testo completoAbstract (sommario):
Abstrak Alga merah (Rhodophyta) merupakan tumbuhan tingkat rendah yang umumnya tumbuh melekat pada substrat tertentu seperti pada karang, lumpur, pasir, batu dan benda keras lainnya. Salah satunya melekat pada mangrove yang merupakan kawasan bernutrisi tinggi. Salah satu daerah yang memiliki hutan mangrove cukup luas ialah Teluk Serewe Kecamatan Jerowaru Lombok Timur. Penelitian ini bertujuan untuk mengetahui keanekaragaman jenis dan karakteristik alga merah yang terdapat pada akar mangrove. Pengambilan sampel pada 4 stasiun menggunakan metode purposive sampling dan jelajah pada saat air surut. Jarak pengambilan sampel yaitu 800 m pada setiap stasiun. Berdasarkan hasil penelitian alga merah yang di peroleh sebanyak 11 spesies yaitu, 4 spesies dari genus Bostrychia, 3 spesies dari genus Caloglossa, 2 spesies dari genus Catenella, 1 spesies dari genus Gelidium, 1 spesies dari genus Stictosiphonia. Karakteristik alga merah yang menempel pada akar mangrove yaitu bentuk talus silindris dan menyerupai daun (blade), percabangan dikotom atau monopodial dengan sel polysiphonous..Kata Kunci: Alga merah, Hutan Mangrove, Lingkungan AbstractRed algae are Thallophyta that generally grow attached to certain substrates such as in coral, mud, sand, and other hard objects. One of them is attached to the mangrove which is a highly nutritious area. One of the forests that have mangrove forest is quite wide is Serewe Village, Jerowaru District East Lombok. This study aims to determine the diversity of species and red algae characteristics found in mangrove root. Sampling at four stations using purposive sampling method and roaming at low tide. The distance of sampling is 800m at each station. Based on the results of the study of red algae obtained as many as 11 species, namely 4 species of the genus Bostrychia, 3 species of genus Caloglassa, 2 species of genus Catenella, 1 species of genus Gelidium, 1 species of genus Stictosiphonia. Characteristics of red algae attached to mangrove root that forms cylindrical thallus and has branching leaf (blade) dichotomy or monopodial with polysiphonous cells.Keyword :Red Algae, Mangrove Forest and Environment.
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Lumbessy, Salnida Yuniarti, Dewi Nur’aeni Setyowati, Alis Mukhlis, Dewi Putri Lestari e Fariq Azhar. "Komposisi Nutrisi dan Kandungan Pigmen Fotosintesis Tiga Spesies Alga Merah (Rhodophyta sp.) Hasil Budidaya". Journal of Marine Research 9, n. 4 (22 novembre 2020): 431–38. http://dx.doi.org/10.14710/jmr.v9i4.28688.
Testo completoAbstract (sommario):
ABSTRAK: Berbagai alga merah memiliki potensi nilai nutrisi dan biopigmen yang dapat dimanfaatkan untuk menambah nilai manfaat serta nilai jual rumput laut. Penelitian ini bertujuan untuk mengetahui komposisi kimia dan kandungan pigmen fotosintesis pada tiga spesies alga merah, yaitu Eucheuma cottonii, Eucheuma spinosum dan Eucheuma striatum yang dibudidayakan di Perairan Sreweh, Lombok Timur, NTB. Ketiga sampel tersebut diambil dalam bentuk segar dari hasil budidaya selama 42 hari. Sampel dianalisa komposisi nutrisi dengan menggunakan uji proksimat sedangkan pigmen fotosintesis diuji dengan menggunakan spktrofotometer. Hasil analisa menunjukkan bahwa E. cottonii mempunyai kandungan lemak (5,77%), serat (15,22%), karbohidrat (47,36%) dan pigmen fikoeritrin (42,88 mg/g) yang tertinggi. Alga merah E. spinosum mempunyai kadar air yang tertinggi (29,72%) dan alga merah E. striatum mempunyai kandungan protein (4,51%), abu (32,49%), klorofil a (30,41 mg/g) dan klorofil b (54,95 mg/g) yang tertinggi. Ketiga spesies alga merahi ini mempunyai potensi sebagai sumber bahan pangan yang dapat meningkatkan nilai nutrisi dan kesehatan pada manusia maupun hewan sehingga dapat memberikan kontribusi sebagai sumber pangan fungsional.ABSTRACT: Various red algae have potential nutritional and biopigment values that can be utilized to add value and sale value of seaweed. This study aims to determine the chemical composition and content of photosynthetic pigments in three species of red algae, namely Eucheuma cottonii, Eucheuma spinosum and Eucheuma striatum cultivated in Sreweh Waters, East Lombok, NTB. The three samples were taken in fresh form the cultivation for 42 days. The nutritional composition of the sample was analyzed using the proximate test while the photosynthetic pigments were tested using a spectrophotometer. The analysis showed that E. cottonii had the highest content of fat (5.77%), fiber (15.22%), carbohydrates (47.36%) and phicoerythrin pigment (42.88 mg / g). Red algae E. spinosum has the highest air content (29, 72%) and red algae E. striatum has protein content (4.51%), ash (32.49%), chlorophyll a (30.41 mg / g) and chlorophyll b (54.95 mg / g) the highest. These three species of red algae have potential as a source of fodd ingredients that can increase nutritional value and health in humans and animals, so that they can contribute as a source of functional food.
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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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YANG, EUN CHAN, e SUNG MIN BOO. "A red alga-specific phycoerythrin gene for biodiversity surveys of callithamnioid red algae". Molecular Ecology Notes 6, n. 2 (giugno 2006): 533–35. http://dx.doi.org/10.1111/j.1471-8286.2005.01216.x.
Testo completo
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Vasileva, Iv, e J. Ivanova. "BIOCHEMICAL PROFILE OF GREEN AND RED ALGAE – A KEY FOR UNDERSTANDING THEIR POTENTIAL APPLICATION AS FOOD ADDITIVES". Trakia Journal of Sciences 17, n. 1 (2019): 1–7. http://dx.doi.org/10.15547/tjs.2019.01.001.
Testo completoAbstract (sommario):
PURPOSE: With the improvements of the microalgal cultivation industry, it became possible to add algal biomass and its metabolites in foods in order to create a balanced and health-food. METHODS: By determining the growth and the biochemical composition (lipids, carbohydrates and proteins), two algal strains were evaluated as a potential source of food additives – the newly isolated strain of the green algae Scenedesmus sp. and the red algae Porphyridium cruentum). RESULTS: It turned out that in Scenedesmus sp. BGP the most abundant component were the proteins (up tp 45 %), which makes this alga an excellent unconventional protein producer. As opposed to it, the biochemical composition of Porphyridium cruentum was dominated by carbohydrates (up to 57%), but there was also a high content of some essential polyunsaturated fatty acids: arachidonic (AA, 20:4; 13-29%) and eicosapentaenoic acid (EPA, 20:5, 24-25%). CONCLUSIONS: Microalgae are a really remarkable source of biomass and a wide range of substances, but this area is poorly explored. Both of the microalgal strains proved to be important sources of functional ingredients that could be successfully used as food additives together or separately.
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Cavalier-Smith, T. "Genomic reduction and evolution of novel genetic membranes and protein-targeting machinery in eukaryote-eukaryote chimaeras (meta-algae)". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, n. 1429 (29 gennaio 2003): 109–34. http://dx.doi.org/10.1098/rstb.2002.1194.
Testo completoAbstract (sommario):
Chloroplasts originated just once, from cyanobacteria enslaved by a biciliate protozoan to form the plant kingdom (green plants, red and glaucophyte algae), but subsequently, were laterally transferred to other lineages to form eukaryote–eukaryote chimaeras or meta–algae. This process of secondary symbiogenesis (permanent merger of two phylogenetically distinct eukaryote cells) has left remarkable traces of its evolutionary role in the more complex topology of the membranes surrounding all non–plant (meta–algal) chloroplasts. It took place twice, soon after green and red algae diverged over 550 Myr ago to form two independent major branches of the eukaryotic tree (chromalveolates and cabozoa), comprising both meta–algae and numerous secondarily non–photosynthetic lineages. In both cases, enslavement probably began by evolving a novel targeting of endomembrane vesicles to the perialgal vacuole to implant host porter proteins for extracting photosynthate. Chromalveolates arose by such enslavement of a unicellular red alga and evolution of chlorophyll c to form the kingdom Chromista and protozoan infrakingdom Alveolata, which diverged from the ancestral chromalveolate chimaera. Cabozoa arose when the common ancestor of euglenoids and cercozoan chlorarachnean algae enslaved a tetraphyte green alga with chlorophyll a and b . I suggest that in cabozoa the endomembrane vesicles originally budded from the Golgi, whereas in chromalveolates they budded from the endoplasmic reticulum (ER) independently of Golgi–targeted vesicles, presenting a potentially novel target for drugs against alveolate Sporozoa such as malaria parasites and Toxoplasma . These hypothetical ER–derived vesicles mediated fusion of the perialgal vacuole and rough ER (RER) in the ancestral chromist, placing the former red alga within the RER lumen. Subsequently, this chimaera diverged to form cryptomonads, which retained the red algal nucleus as a nucleomorph (NM) with approximately 464 protein–coding genes (30 encoding plastid proteins) and a red or blue phycobiliprotein antenna pigment, and the chromobiotes (heterokonts and haptophytes), which lost phycobilins and evolved the brown carotenoid fucoxanthin that colours brown seaweeds, diatoms and haptophytes. Chromobiotes transferred the 30 genes to the nucleus and lost the NM genome and nuclear–pore complexes, but retained its membrane as the periplastid reticulum (PPR), putatively the phospholipid factory of the periplastid space (former algal cytoplasm), as did the ancestral alveolate independently. The chlorarachnean NM has three minute chromosomes bearing approximately 300 genes riddled with pygmy introns. I propose that the periplastid membrane (PPM, the former algal plasma membrane) of chromalveolates, and possibly chlorarachneans, grows by fusion of vesicles emanating from the NM envelope or PPR. Dinoflagellates and euglenoids independently lost the PPM and PPR (after diverging from Sporozoa and chlorarachneans, respectively) and evolved triple chloroplast envelopes comprising the original plant double envelope and an extra outermost membrane, the EM, derived from the perialgal vacuole. In all metaalgae most chloroplast proteins are coded by nuclear genes and enter the chloroplast by using bipartite targeting sequences – an upstream signal sequence for entering the ER and a downstream chloroplast transit sequence. I present a new theory for the four–fold diversification of the chloroplast OM protein translocon following its insertion into the PPM to facilitate protein translocation across it (of both periplastid and plastid proteins). I discuss evidence from genome sequencing and other sources on the contrasting modes of protein targeting, cellular integration, and evolution of these two major lineages of eukaryote ‘cells within cells’. They also provide powerful evidence for natural selection's effectiveness in eliminating most functionless DNA and therefore of a universally useful non–genic function for nuclear non–coding DNA, i.e. most DNA in the biosphere, and dramatic examples of genomic reduction. I briefly argue that chloroplast replacement in dinoflagellates, which happened at least twice, may have been evolutionarily easier than secondary symbiogenesis because parts of the chromalveolate protein–targeting machinery could have helped enslave the foreign plastids.
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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.
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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.
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Balaji Prasath, Barathan, Ying Wang, Yuping Su, Wanning Zheng, Hong Lin e Hong Yang. "Coagulant Plus Bacillus nitratireducens Fermentation Broth Technique Provides a Rapid Algicidal Effect of Toxic Red Tide Dinoflagellate". Journal of Marine Science and Engineering 9, n. 4 (8 aprile 2021): 395. http://dx.doi.org/10.3390/jmse9040395.
Testo completoAbstract (sommario):
When the toxic red tide alga Gymnodinium catenatum H.W. Graham accumulates in sediment through sexual reproduction, it provides the provenance of a periodic outbreak of red tide, a potential threat to the marine environment. In our study, the flocculation effects of four coagulants were compared. Bacteria fermentation (Ba3) broth and coagulant were combined with Ba3 to reduce the vegetative cells of G. catenatum, inhibit the cystic germination in the sediment, and control the red tide outbreak. To promote a more efficient and environmentally friendly algae suppression method, we studied these four coagulants combined with algae suppression bacteria for their effect on G. catenatum. The results show that polyaluminum chloride (PAC) is more efficient than other coagulants when used alone because it had a more substantial inhibitory effect. Ba3 broth also had a beneficial removal effect on the vegetative cells of G. catenatum. The inhibition efficiency of 2-day fermentation liquid was higher than that of 1-day and 3-day fermentation liquids. When combined, the PAC and Ba3 broth produced a pronounced algae inhibition effect that effectively hindered the germination of algae cysts. We conclude that this combination provides a scientific reference for the prevention and control of marine red tide. Our results suggest that designing environmentally friendly methods for the management of harmful algae is quite feasible.
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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.
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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.
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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.
Testo completo
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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.
Testo completo
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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.
Testo completo
49
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.
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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.