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Non-indigenous species (NIS) have the potential to colonize and become established in a wide range of coastal habitats. Species with broad environmental tolerances can quickly adapt to local conditions and expand their niches along environmental gradients, and even colonize habitats with extreme abiotic conditions. Here we report and document the distribution of eight marine NIS (four seaweed and four invertebrate species) found in tidepools along a 3000 km latitudinal gradient along the Pacific coast of Chile (18.4°S to 41.9°S). The seaweed NIS Codium fragile, Capreolia implexa, Schottera nicaeensis and Mastocarpus latissimus were mostly distributed towards high latitudes (i.e., more southerly locations), where temperatures in tidepools were low. The invertebrate NIS Anemonia alicemartinae, Ciona robusta, Bugula neritina and Bugulina flabellata were more common towards low latitudes, where high temperatures were registered in the tidepools. Across the intertidal gradient, seaweed NIS were mostly found in pools in the mid and low intertidal zone, while invertebrate NIS occurred mostly in pools from the mid and upper intertidal zones. The realized niche spaces of NIS (based on the Outlying Mean Index, OMI) in the study area were mainly influenced by environmental conditions of temperature and salinity (along the latitudinal and intertidal gradients), while other tidepool characteristics (depth, surface area, exposition, and complexity) only had minor effects. Five of the eight NIS exhibited a realized niche space coinciding with the average tidepool environmental conditions, while marginal niches were occupied by species with affinities for specific temperatures and salinities along the latitudinal and intertidal gradients. Our results indicate that physiological tolerances to environmental factors play a fundamental role in the distribution of seaweed and invertebrate NIS in tidepools along the Chilean coast. This study confirms that tidepools offer suitable conditions for some seaweed and invertebrate NIS, potentially facilitating their invasion into new natural habitats.

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Brazil has a megadiversity that includes marine species that are distributed along 800 km of shoreline. This biodiversity status holds promising biotechnological potential. Marine organisms are important sources of novel chemical species, with applications in the pharmaceutical, cosmetic, chemical, and nutraceutical fields. However, ecological pressures derived from anthropogenic actions, including the bioaccumulation of potentially toxic elements and microplastics, impact promising species. This review describes the current status of the biotechnological and environmental aspects of seaweeds and corals from the Brazilian coast, including publications from the last 5 years (from January 2018 to December 2022). The search was conducted in the main public databases (PubChem, PubMed, Science Direct, and Google Scholar) and in the Espacenet database (European Patent Office-EPO) and the Brazilian National Property Institute (INPI). Bioprospecting studies were reported for seventy-one seaweed species and fifteen corals, but few targeted the isolation of compounds. The antioxidant potential was the most investigated biological activity. Despite being potential sources of macro- and microelements, there is a literature gap regarding the presence of potentially toxic elements and other emergent contaminants, such as microplastics, in seaweeds and corals from the Brazilian coast.

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The process by which cancer cells evade or inhibit apoptosis is considered one of the characteristics of cancer. The ability of cancer cells to escape apoptosis contributes to tumor proliferation and promotes metastasis. The discovery of new antitumor agents is essential for cancer treatment due to the lack of selectivity of drugs and cellular resistance to anticancer agents. Several studies showed that macroalgae produce various metabolites with different biological activities among marine organisms. This review discusses multiple metabolites extracted from macroalgae and their pro-apoptotic effects through regulating apoptosis signaling pathway target molecules and the structure-activity relationship. Twenty-four promising bioactive compounds have been reported, where eight of these compounds exhibited values of maximum inhibitory concentration (IC50) of less than 7 µg/mL. Fucoxanthin was the only carotenoid reported that induced apoptosis in HeLa cells with an IC50 below 1 µg/mL. Se-PPC (a complex of proteins and selenylated polysaccharides) is the magistral compound because it is the only one with an IC50 of 2.5 µg/mL which regulates the primary proteins and critical genes of both apoptosis pathways. Therefore, this review will help provide the basis for further studies and the development of new anticancer drugs, both as single agents and adjuvants, decreasing the aggressiveness of first-line drugs and offering patients better survival and quality of life.

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Although seaweeds exhibit many benefits as a food source, few studies have characterized their sensory attributes. An expert nine-member panel developed a vocabulary with 25 descriptors to describe the appearance, aroma, flavor, texture, and aftertaste of raw and cooked seaweeds consumed in Chile: Durvillaea antarctica, Pyropia spp., and Ulva lactuca. Subsequently, the vocabulary was used in a ranking descriptive analysis (RDA) to evaluate the sensory properties and relate them with physicochemical and physical data. Sensory attributes of the three seaweeds were very different from each other but similar between treatments (raw and cooked). Pyropia spp., both cooked and hydrated, had the highest glutamate content (310 and 324 mg (100 g) -1 d.w., respectively), and was perceived by the sensory panel as having the most umami taste. Cooked D. antarctica was perceived as sweeter, had more caramel notes than the hydrated seaweed and was sensed as cartilaginous and hard in accordance with its mechanical properties. Generalized Procrustes analysis revealed that D. antarctica exhibited most of the desirable descriptors, such as caramel, umami and marine aromas while U. lactuca was described as bitter and moldy. This primary vocabulary can assist food scientists and chefs in the development of seaweed products and dishes for the consumer market.

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In some coastal areas, large quantities of beach-cast macroalgae can accumulate and are usually considered waste and disposed of. However, due to their biofunctional and nutritional properties, they have great potential as a new source of raw materials. Increasing population growth has made the search for alternative raw materials with valuable nutritional properties urgent; here, beach-cast macroalgae could provide great potential. Our research goal was to characterize the nutritional profile of 12 beach-cast seaweed species from the Brazilian coast to assess their potential valorization. A considerable number of nutritional compounds was observed, such as ash (6.5-59.3%), total dietary fibers (22.1-65.8%), proteins (5.1-21.5%), and carbohydrates (31.4-81.0%), with an expressive abundance of minerals, free amino acids, and fatty acids. Spatoglossum schroederi and Alsidium seaforthii showed protein contents of 21.5 ± 0.2%, 19.7 ± 0.1%, and high amounts of total dietary fiber of 59.2 ± 0.4%, 61.7 ± 4.9%, respectively. The overall profile suggests that beach-cast seaweeds are suitable for nutritional and other bioeconomical purposes, to which different species with different characteristics contribute. Contamination of these seaweeds with unwanted toxic compounds like micropollutants was not studied. However, this must be considered before they are used for human consumption.

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Undaria pinnatifida is a brown algae native to Asia that has settled in various regions worldwide, periodically contributing with large quantities of C and nutrients during its annual cycle. In this work, we analyzed a coastal site in Patagonia (Argentina) that has been colonized for three decades by U. pinnatifida, focusing on associated microbial communities in three different compartments. An important influence of algae was observed in seawater, especially in the bottom of the algal forest during the austral summer (January) at the moment of greater biomass release. This was evidenced by changes in DOC concentration and its quality indicators (higher Freshness and lower Humification index) and higher DIC. Although maximum values of NH4 and PO4 were observed in January, bottom water samples had lower concentrations than surface water, suggesting nutrient consumption by bacteria during algal DOM release. Concomitantly, bacterial abundance peaked, reaching 4.68 ± 1.33 × 105 cells mL -1 (January), showing also higher capability of degrading alginate, a major component of brown algae cell walls. Microbial community structure was influenced by sampling date, season, sampling zone (surface or bottom), and environmental factors (temperature, salinity, pH, dissolved oxygen, nutrients). Samples of epiphytic biofilms showed a distinct community structure compared to seawater, lower diversity, and remarkably high alginolytic capability, suggesting adaptation to degrade algal biomass. A high microdiversity of populations of the genus Leucothrix (Gammaproteobacteria, Thiotrichales) that accounted for a large fraction of epiphytic communities was observed, and changed over time. Epiphytic assemblages shared more taxa with bottom than with surface seawater assemblages, indicating a certain level of exchange between communities in the forest surroundings. This work provides insight into the impact of U. pinnatifida decay on seawater quality, and the role of microbial communities on adapting to massive biomass inputs through rapid DOM turnover.

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One of the most important factors regulating the distribution and abundance of seaweeds is desiccation, triggered mainly by tidal changes and climatic variation. Porphyra and Pyropia species have evolved multiple strategies to tolerate desiccation stress; however, how these tolerance strategies differ in these species inhabiting different latitudes is still unknown. In this context, we analyzed, in situ, the physiological responses of these species (collected from 18° S to 41° S along the Chilean coast) to desiccation stress using biochemical and molecular analyses. The hyper-arid terrestrial climate of northern Chile, with high evaporation and lack of constant rain determines a very steep increase in desiccation stress in the upper intertidal during low tide for these species. Accordingly, the results showed that, in comparison with the southernmost populations, the Porphyra/Pyropia species from the north zone of Chile (18°-30° S) exhibited higher contents of lipoperoxide and carbonyls (1.6-1.9 fold) together with higher enzymatic activities, including ascorbate peroxidase, catalase, peroxiredoxin, and thioredoxin (2-3-fold). In addition, a substantial expression of cat, prx, and trx transcripts during desiccation was demonstrated, mainly in the northernmost populations. These results provide evidence of (i) significant activation of antioxidant enzymes and transcripts (principally cat and prx); (ii) participation of phenolic antioxidant compounds as a highly plastic physiological strategy to cope with desiccation; and (iii) the activation of the tolerance responses was affected by species latitudinal distribution. Thus, for the first time, this study integrated the biochemical and genetic responses of diverse Porphyra/Pyropia species to better understand their physiological dynamics of tolerance over a wide latitudinal range.

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Brown seaweed phlorotannins have shown the potential to promote several health benefits. Durvillaea incurvata and Lessonia spicata-species that are widely distributed in central and southern Chile-were investigated to obtain phlorotannin extracts with antioxidant and antihyperglycemic potential. The use of an environmentally friendly and food-grade glycerol-based pressurized hot liquid extraction (PHLE) process (15% v/v glycerol water) was assessed for the first time to obtain phlorotannins. Multiple effects were analyzed, including the effect of the species, harvesting area (Las Cruces and Niebla), and anatomical part (holdfast, stipe, and frond) on the extracts' polyphenol content (TPC), antioxidant capacity (AC), and carbohydrate-hydrolyzing enzyme-α-glucosidase and α-amylase-inhibitory activity. Contaminants, such as mannitol, heavy metals (As, Cd, Pb, Hg, and Sn), and 5-hydroxymethylfurfural (HMF), were also determined. The anatomical part used demonstrated a significant impact on the extracts' TPC and AC, with holdfasts showing the highest values (TPC: 95 ± 24 mg phloroglucinol equivalents/g dry extract; DPPH: 400 ± 140 µmol Trolox equivalents/g dry extract; ORAC: 560 ± 130 µmol TE/g dry extract). Accordingly, holdfast extracts presented the most potent α-glucosidase inhibition, with D. incurvata from Niebla showing an activity equivalent to fifteen times that of acarbose. Only one frond and stipe extract showed significant α-glucosidase inhibitory capacity. No α-amylase inhibition was found in any extract. Although no HMF was detected, potentially hazardous cadmium levels (over the French limit) and substantial mannitol concentrations-reaching up to 50% of the extract dry weight-were found in most seaweed samples and extracts. Therefore, further purification steps are suggested if food or pharmaceutical applications are intended for the seaweed PHLE extracts obtained in this study.

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The biomedical potential of the edible red seaweed Agarophyton chilense (formerly Gracilaria chilensis) has not been explored. Red seaweeds are enriched in polyunsaturated fatty acids and eicosanoids, which are known natural ligands of the PPARγ nuclear receptor. PPARγ is the molecular target of thiazolidinediones (TZDs), drugs used as insulin sensitizers to treat type 2 diabetes mellitus. Medical use of TZDs is limited due to undesired side effects, a problem that has triggered the search for selective PPARγ modulators (SPPARMs) without the TZD side effects. We produced Agarophyton chilense oleoresin (Gracilex®), which induces PPARγ activation without inducing adipocyte differentiation, similar to SPPARMs. In a diet-induced obesity model of male mice, we showed that treatment with Gracilex® improves insulin sensitivity by normalizing altered glucose and insulin parameters. Gracilex® is enriched in palmitic acid, arachidonic acid, oleic acid, and lipophilic antioxidants such as tocopherols and ß-carotene. Accordingly, Gracilex® possesses antioxidant activity in vitro and increased antioxidant capacity in vivo in Caenorhabditis elegans. These findings support the idea that Gracilex® represents a good source of natural PPARγ ligands and antioxidants with the potential to mitigate metabolic disorders. Thus, its nutraceutical value in humans warrants further investigation.

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The 2019-2020 Brazil oil spill disaster affected several ecosystems and species-rich areas. The shallow-water reefs of Paiva beach are among the best-preserved coastal environments in the State of Pernambuco (NE Brazil), but were severely affected by oil arrival at the end of 2019. The reefs are densely covered by macroalgae as important biogenic substrates for benthic fauna. Based on that, herein, we provide a baseline assessment of the immediate impacts of the oil spill on the structure of epifaunal communities associated with the algae Jania capillacea and Penicillus capitatus. The benthic communities in both algae simplified (reduction of species richness and abundance) soon after oil arrival, while opportunistic taxa increased. After two months, the macrofaunal communities restructured to almost pre-disaster levels. However, polychaeta diversity remained low. Despite the apparently fast recovery of reef macrobenthos, a more detailed, long-term monitoring is necessary to evaluate the chronic effects.

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In the current review, compositional data on fucoidans extracted from more than hundred different species were surveyed through the available literature. The analysis of crude extracts, purified extracts or carefully isolated fractions is included in tabular form, discriminating the seaweed source by its taxonomical order (and sometimes the family). This survey was able to encounter some similarities between the different species, as well as some differences. Fractions which were obtained through anion-exchange chromatography or cationic detergent precipitation showed the best separation patterns: the fractions with low charge correspond mostly to highly heterogeneous fucoidans, containing (besides fucose) other monosaccharides like xylose, galactose, mannose, rhamnose, and glucuronic acid, and contain low-sulfate/high uronic acid proportions, whereas those with higher total charge usually contain mainly fucose, accompanied with variable proportions of galactose, are highly sulfated and show almost no uronic acids. The latter fractions are usually the most biologically active. Fractions containing intermediate proportions of both polysaccharides appear at middle ionic strengths. This pattern is common for all the orders of brown seaweeds, and most differences appear from the seaweed source (habitat, season), and from the diverse extraction, purification, and analytitcal methods. The Dictyotales appear to be the most atypical order, as usually large proportions of mannose and uronic acids appear, and thus they obscure the differences between the fractions with different charge. Within the family Alariaceae (order Laminariales), the presence of sulfated galactofucans with high galactose content (almost equal to that of fucose) is especially noteworthy.

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Galactans are important components of many plant cell walls. Besides, they are the major polysaccharides in extracellular matrixes from different seaweeds, and other marine organisms, which have an acidic character due to the presence of sulfate groups in their structures. In particular, most of the red seaweeds biosynthesize sulfated galactans with very special linear backbones, constituted by alternating (1→3)-ß-d-galactopyranose units (A-unit) and (1→4)-α-galactopyranose residues (B-unit). In the industrially significant seaweeds as source of hydrocolloids, B-units belong either to the d-series and they produce carrageenans (as in the order Gigartinales), or to the l-series, and they are sources of agarose and/or structurally related polymers (i.e., Gelidiales, Gracilariales). In both cases, the latter units appear as cyclized 3,6-anhydro-α-galactose in certain amounts, which can be increased by alkaline cyclization of α-galactose 6-sulfate units. Besides, it has been clearly shown that some red algae produce different amounts of both galactan structures, known as d/l-hybrids. It is not yet clear if they comprise both diasteromeric types of units in the same molecule, or if they are mixtures of carrageenans and agarans that are very difficult to separate. It has been reported that the biosynthesis of these galactans, showing that the nucleotide transport for d-galactopyranose units is UDP-d-Gal, while for l-galactose, it is GDP-l-Gal, so, there is a different pathway in the biosynthesis of agarans. However, at least in those seaweeds that produce carrageenans as major galactans, but also agarans, both synthetic pathways should coexist. Another interesting characteristic of these galactans is the important variation in the sulfation patterns, which modulate their physical behavior in aqueous solutions. Although the most common carrageenans are of the κ/ι- and λ-types (with A-units sulfated at the 4- and 2-positions, respectively) and usually in agarans, when sulfated, is at the 6-position, many other sulfate arrangements have been reported, greatly influencing the functional properties of the corresponding galactans. Other substituents can modify their structures, as methyl ethers, pyruvic acid ketals, acetates, and single stubs of xylose or other monosaccharides. It has been shown that structural heterogeneity at some extent is essential for the proper functional performance of red algal galactans.

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Geographic variation of phenotypic traits affects the capacity of species to withstand and adapt to environmental stress. Here, we examined how geographic origin influences UV stress tolerance of the red seaweeds Chondracanthus chamissoi and Gelidium lingulatum distributed along the South-East Pacific coast between 20° S and 42° S. Seaweeds from six (C. chamissoi) and five (G. lingulatum) populations were grown under common-garden conditions and then exposed to consecutive UV stress events and essential biological traits (e.g., growth, photosynthetic responses, antioxidant capacity, and UV-absorbing compounds) were analyzed. In C. chamissoi, a strong UV sensitivity occurred in populations from mid-latitudes (27° S and 29° S) where the lowest recovery of maximum quantum yield (Fv /Fm ; between 32.3% and 66.8% of control) and growth rate were observed. Likewise, the lowest amount of mycosporine-like amino acids (MAAs) and a significant decrease in phycobilins were registered in these populations. In G. lingulatum, recovery of Fv /Fm ranged from 82.0% to 97.7% of control, and antioxidant activity, carotenoid, and MAA contents were positively influenced by UV exposure. The multivariate analysis indicated a significant influence of PAR, cloud cover, and UV index on physiological traits, depending on species. The ecotypic differentiation index (EDI) indicated a higher phenotypic variation in C. chamissoi (EDI = 0.10) than G. lingulatum (EDI = 0.03). This study shows that the spatial distribution of UV stress tolerance in the studied seaweeds does not follow linear latitudinal or central-edge gradients. Instead, among-site variability of solar intensities driven by specific climatic conditions seems to act as driver of phenotypic variation.

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Floating seaweeds are important dispersal vectors in marine ecosystems. However, the relationship between benthic populations and stranded seaweeds has received little attention. After detachment, a fraction of floating specimens returns to the shore, resulting in strandings that fluctuate in space and time. It has been hypothesized that the availability of stranded seaweeds is related to their benthic abundance on adjacent coasts. Using the large fucoid Durvillaea antarctica, we tested whether stranded biomasses are higher at sites with dense adjacent benthic populations. Benthic abundance of D. antarctica along the continental coast of Chile was estimated using three approximations: (i) availability of potentially suitable habitat (PSH), (ii) categorical visual abundance estimates in the field, and (iii) abundance measurements in the intertidal zone. Higher PSH for D. antarctica was observed between 31° S-32° S and 40° S-42° S than between 33° S and 39° S. Lowest benthic biomasses were estimated for the northern latitudes (31° S-32° S). Regression models showed that the association between stranded biomass and PSH was highest when only the extent of rocky shore 10 km to the south of each beach was included, suggesting relatively short-distance dispersal and asymmetrical transport of floating kelps, which is further supported by low proportions of rafts with Lepas spp. (indicator of rafting). The results indicate that stranded biomasses are mostly subsidized by nearby benthic populations, which can partly explain the low genetic connectivity among populations in the study region. Future studies should also incorporate other local factors (e.g., winds, currents, wave-exposure) that influence stranding dynamics.

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Two thirds of the world is covered by oceans, whose upper layer is inhabited by algae. This means that there is a large extension to obtain these photoautotrophic organisms. Algae have undergone a boom in recent years, with consequent discoveries and advances in this field. Algae are not only of high ecological value but also of great economic importance. Possible applications of algae are very diverse and include anti-biofilm activity, production of biofuels, bioremediation, as fertilizer, as fish feed, as food or food ingredients, in pharmacology (since they show antioxidant or contraceptive activities), in cosmeceutical formulation, and in such other applications as filters or for obtaining minerals. In this context, algae as food can be of help to maintain or even improve human health, and there is a growing interest in new products called functional foods, which can promote such a healthy state. Therefore, in this search, one of the main areas of research is the extraction and characterization of new natural ingredients with biological activity (e.g., prebiotic and antioxidant) that can contribute to consumers' well-being. The present review shows the results of a bibliographic survey on the chemical composition of macroalgae, together with a critical discussion about their potential as natural sources of new functional ingredients.

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Spore settlement and development are bottlenecks for resilience of habitat-forming macroalgal species. These processes are directly related to temperature, a global stressor protagonist of ocean warming. The toxic effects of local pollutants such as copper may be worsened under a global warming scenario. Therefore, in this paper, we investigated the effects of increased temperature combined with elevated concentrations of copper on the viability, photosynthetic pigments, and ultrastructure of Gelidium floridanum tetraspores. Tetraspores were cultivated on slides with sterilized seawater or seawater enriched with CuCl2 , and incubated under 24°C or 30°C for 24 h. Tetraspores cultivated with copper 3.0 µM under 30°C had lower viability. Both temperature and copper had a significant effect on phycocyanin and phycoerythrin concentrations. Samples cultivated with copper under 30°C presented a heavily altered cellular structure, with vesicles throughout the cytoplasm, chloroplasts with altered structure and cells with degenerated cytoplasm and cell walls. Our findings show that temperature and copper significantly affect the viability, photosynthetic pigments, and ultrastructure of G. floridanum tetraspores, presenting an additive interaction for the physiology of this seaweed's early stages.

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Phlorotannins are primary and/or secondary metabolites found exclusively in brown seaweeds, but their geographic distribution and abundance dynamic are not very well understood. In this study we evaluated the phlorotannin concentrations among and within-species of brown seaweeds in a broad latitudinal context (range of 21°) along the Brazilian coast (Southwestern Atlantic), using the Folin-Ciocalteau colorimetric method. In almost all species (16 out of 17) very low phlorotannin concentrations were found (<2.0%, dry weight for the species), confirming reports of the typical amounts of these chemicals in tropical brown seaweeds, but with significantly distinct values among seven different and probably highly structured populations. In all 17 seaweed species (but a total of 25 populations) analyzed there were significant differences on the amount of phlorotannins in different individuals (t-test, p < 0.01), with coefficients of variation (CV) ranging from 5.2% to 65.3%. The CV, but not the total amount of phlorotannins, was significantly correlated with latitude, and higher values of both these variables were found in brown seaweeds collected at higher latitudes. These results suggest that brown seaweeds from higher latitudes can produce phlorotannins in a wider range of amounts and probably as response to environmental variables or stimuli, compared to low latitude algae.

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The brown seaweed Scytosiphon lomentaria produces moderate amounts of fucoidans. By cetrimide fractionation, typical heavily sulfated galactofucans are obtained, with no major signs of chemical heterogeneity, together with fractions with higher proportions of xylose, mannose and uronic acids. Anyway, fucose is the most important monosaccharide in most of the subfractions of the subsequent extracts. The fucan moieties appear to be mostly as 3-linked α-l-fucopyranosyl units, with several patterns of sulfate and branching. Galactose is mostly 6-linked, whereas mannose appears to be 2-linked, and xylose appears mostly as terminal stubs. Small amounts of 2-O-acetylated fucose units appear. A high and selective antiviral activity against HSV-1 and HSV-2 was determined for the galactofucan fractions whereas the uronofucoidans were inactive.

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Abstract Seaweeds are accessible and important marine organisms found in coastal zones, which have shown their nutritive potential as food or additive. These organisms are relatively abundant in the coastline of Ecuador, but their biochemical composition has not been adequately studied. Therefore, the aim of this research was to evaluate the proximate composition of seven seaweeds (four red, two brown, and one green) collected from Salinas Bay, Ecuador, as a contribution to the knowledge of the nutritional potential of these organisms that belong to this region. Moisture, ash, fat, fiber and protein contents were determined by standard protocols, while carbohydrates were obtained by difference. Energetic content (or caloric profile) was calculated according to the contributions of macromolecules (fats, proteins and carbohydrates). The parameters in highest proportion found in all species were carbohydrates (32.2-45.5 %) and minerals (or ash, 25.8-36.7 %), which play a significant role in human nutrition and the food industry. Furthermore, protein, fiber, and fat contents were relatively low, with values around 4.7-8.0 %, 0.9-5.0 %, and 0.3-3.0 %, respectively, indicating these organisms are a good option as healthy food. According to statistical analysis (ANOVA), each nutritive parameter was significantly different among the species (P < 0.05). Results indicate edible seaweeds from Ecuador have potential as nutritious food that could offer between 1 500-2 000 kcal kg-1, which is higher than many common vegetables.(AU)

Resumen Las macroalgas marinas son organismos accesibles e importantes de las zonas costeras, los cuales han mostrado su potencial como alimentos o aditivos nutritivos. En la línea costera de Ecuador estos organismos son relativamente abundantes, pero su composición bioquímica no ha sido estudiada adecuadamente. En consecuencia, el objetivo de esta investigación fue evaluar la composición proximal de siete especies de macroalgas (cuatro rojas, dos pardas y una verde) que fueron recolectadas en la Bahía de Salinas, Ecuador, como una contribución al conocimiento del potencial nutricional de estos organismos pertenecientes a esta región. Los contenidos de humedad, cenizas, grasa, fibra y proteínas fueron determinadas mediante protocolos estándares, mientras que el contenido de carbohidrato fue obtenido por diferencia. El contenido energético (o perfil calórico) de las macroalgas fue calculado de acuerdo con las contribuciones de las macromoléculas (grasas, proteínas y carbohidratos). Los parámetros encontrados en mayor proporción en todas las especies fueron: carbohidratos (32.2-45.5 %) y minerales (o cenizas, 25.8-36.7 %), los cuales tienen importancia en la nutrición humana y la industria alimentaria. Además, los contenidos de proteína, fibra y grasa fueron relativamente bajos, encontrando valores alrededor de 4.7-8.0, 0.9-5.0, y 0.3-3.0 %, respectivamente, indicando que estos organismos son una buena y saludable opción como alimento. De acuerdo con el análisis estadístico (ANOVA), cada parámetro nutritivo fue significativamente diferente entre especies (P < 0.05). Los resultados indican que las algas comestibles de Ecuador tienen potencial como alimento nutritivo que pueden ofrecer entre 1 500-2 000 kcal kg-1, un aporte energético un poco mayor que muchos vegetales comunes.(AU)

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Different hydrolysis conditions to produce κ-carrageenan oligosaccharide alditols were studied and the depolymerization process monitored by capillary electrophoresis (CE). Semisynthesis, ion-exchange and exclusion chromatography were used to obtain and isolate sulfated di-, tetra- and hexasaccharide alditols, the last being fully characterized for the first time. Those derivatives were used as standards to validate a new quantitative CE analytical method which was used to compare two different partial hydrolysis methodologies: an acid hydrolysis followed by reduction and a one-pot reductive hydrolysis using 4-methylmorpholine borane. The resulting depolymerization profiles were quite different from each other. Optimal hydrolysis conditions to produce high yields of specific sulfated oligosaccharides as well as particular mixtures of oligosaccharide alditols were determined. Moreover, using the novel CE method, we were able to distinguish up to eight different oligosaccharides in the hydrolysate mixtures.