Sargassum Muticum Research Articles

Sargassum muticum (Yendo) Fensholt (Fucales, Phaeophyta) in Morocco, an invasive marine species new to the Atlantic coast of Africa

The Japanese brown seaweed Sargassum muticum (Yendo) Fensholt (Fucales, Phaeophyta) is reported for the first time in Atlantic Morocco, along the shoreline of Doukkala (S of Casablanca). This record, the first in the African continent, represents a remarkable range expansion of this invasive marine species. Indeed, it is the southern-most occurrence of the species in the Atlantic. Preliminary phenological and ecological data of this non-native species were provided from the Doukkala coast. The major effects on benthic structure and composition of this invasive brown macroalga were also evaluated from published data. Oyster transfers from the French coast were the most likely primary

Functional diversity and climate change: effects on the invasibility of macroalgal assemblages

Climate-driven and biodiversity effects on the structure and functioning of ecosystems are increasingly studied as multiple stressors, which subsequently may influence species invasions. We used a mesocosm experiment to test how increases in temperature and CO2 partial pressure (pCO2) interact with functional diversity of resident macroalgal assemblages and affect the invasion success of the non-indigenous macroalga Sargassum muticum. Early settlement of S. muticum germlings was assessed in the laboratory under common environmental conditions across three monocultures and a polyculture of functional groups of native macroalgae, which had previously grown for 3 weeks under crossed treatments of temperature and pCO2. Functional diversity was a key driver shaping early settlement of the invader, with significant identity and richness effects: higher settlement occurred in low-diversity and low-stature assemblages, even after accounting for treatment biomass. Overall, early survivorship of settled germlings responded to an interaction of temperature and pCO2 treatments, with survivorship enhanced in one treatment (high pCO2 at ambient Temperature) after 3 days, and reduced in another (ambient pCO2 at high Temperature) after 10 days, although size was enhanced in this same treatment. After 6 months in the field, legacy effects of laboratory treatments remained, with S. muticum reaching higher cover in most assemblages previously subjected to ambient pCO2, but ephemeral green algae appearing disproportionately after elevated-pCO2 treatment. These results caution that invasion outcomes may change at multiple points in the life cycle under higher-CO2, higher-temperature conditions, in addition to supporting a role for intact, functionally diverse assemblages in limiting invader colonization.

Antioxidant, antiproliferative, and antiangiogenesis effects of polyphenol-rich seaweed (Sargassum muticum).

In the present study, we evaluated the effect of brown seaweeds Sargassum muticum methanolic extract (SMME), against MCF-7 and MDA-MB-231 breast cancer cell lines proliferation. This algae extract was also evaluated for reducing activity and total polyphenol content. The MTT assay results indicated that the extracts were cytotoxic against breast cancer cell lines in a dose-dependent manner, with IC50 of 22 μg/ml for MCF-7 and 55 μg/ml for MDA-MB-231 cell lines. The percentages of apoptotic MCF-7-treated cells increased from 13% to 67% by increasing the concentration of the SMME. The antiproliferative efficacy of this algal extract was positively correlated with the total polyphenol contents, suggesting a causal link related to extract content of phenolic acids. Cell cycle analysis showed a significant increase in the accumulation of SMME-treated cells at sub-G1 phase, indicating the induction of apoptosis by SMME. Further apoptosis induction was confirmed by Hoechst 33342 and AO/PI staining. Also SMME implanted in vivo into fertilized chicken eggs induced dose-related antiangiogenic activity in the chorioallantoic membrane (CAM). Our results imply a new insight on the novel function of Sargassum muticum polyphenol-rich seaweed in cancer research by induction of apoptosis, antioxidant, and antiangiogenesis effects.

Introduced Marine Macroalgae in the Port of Ensenada, Baja California, Mexico: Biological Contamination

The variety of marine coastal environments of Mexico has been scientifically recognized; allowing the high diversity of organisms. The floristic richness (macroalgae species) includes giant kelps of cold environments of the Pacific coast, which are economically and ecologically important. This also includes a wide variety of macroalgae species from temperate and tropical environments. This ecological diversity is currently threatened and affected by the impact of climate change and by the non-native species introduction related by increased tourist routes and commercial navigation to Baja California shores. Based on a monitoring program of introduced macroalgae species, in the last 15 years several non-native species have been collected in the facilities of the port of Ensenada, Baja California. The species Sargassum muticum, Sargassum filicinum, Grateloupia turuturu and Grateloupia lanceolata, grow on different substrates in the Port, and because they grow abundantly, tend to displace native species and are therefore considered biological contamination. This work includes a review of the introduced macroalgae to the Port of Ensenada, their current distribution in Mexico and discusses its probable origin and possible vectors of introduction.

Propagule pressure and functional diversity: interactive effects on a macroalgal invasion process

Invasive species are considered an increasing global threat to marine ecosystems. Understanding which factors can accelerate or reduce invasion success is one of the main goals of invasion ecology. The present study investigated the interactive effects of propagule pressure and native functional diversity on the invasion success of the invasive alga Sargassum muticum (Yendo) Fensholt over a 1 yr invasion process (i.e. settlement, recruitment and colonisation). The invasibility of macroalgal assemblages with different functional diversity was assessed under high and low propagule pressure. Synthetic assemblages resembling natural marine macroalgal assemblages were built and used as model systems. Recruitment discs were used to record early settlement in the assemblages. Recruitment and colonisation success were monitored in the field 2 and 10 mo after exposure to propagule rain in the laboratory. The availability of resources (space and photosynthetically active radiation (PAR)) was also monitored for each assemblage and used as predictive variables in the analyses. The effects of propagule pressure and functional diversity varied among the invasion stages. Space availability did not play a significant role in the recruit- ment success of the invader. However, PAR was a key resource in its invasion success. Overall, the invasion success of S. muticum was influenced differently by different traits of the recipient assemblages. Hence, invasion success may be better explained by the interaction of environmen- tal factors that co-vary with species diversity and identity at different invasion stages.

Alginic acid and derivatives, new polymers from the endangered Pancratium maritimum L.

Alginic acid and derivatives were reported for the first time from the bulb of Pancratium maritimum L. The brown algae Sargassum muticum was used as a source of sodium alginate. The alginic acid and calcium alginate production methods were performed. FT-IR spectra of sodium alginate extracted from P. maritimum reported an intense peak around 1614cm−1 and a second intense peak around 1431cm−1. Our analysis showed that the sodium alginate characteristic peaks of P. maritimum and S. muticum were similar. Chemical data in our study can provide some insight into the bioactive molecules in the species with important industrial and pharmaceutical uses and may lead to use P. maritimum as a new source of sodium alginate.

Response of macroalgal assemblages from rockpools to climate change: effects of persistent increase in temperature and CO2

Anthropogenically induced global climate change has important implications for marine ecosystems with unprecedented ecological and economic consequences. Climate change will include the simultaneous increase of temperature and CO2 concentration in oceans. However, experimental manipulations of these factors at the community scale are rare. In this study, we used an experimental approach in mesocosms to analyse the combined effects of elevated CO2 and temperature on macroalgal assemblages from intertidal rock pools. Our model systems were synthetic assemblages of varying diversity and understory component and canopy species identity. We used assemblages invaded by the non‐indigenous canopy forming alga Sargassum muticum and assemblages with the native canopy species Cystoseira tamariscifolia. We examined the effects of both climate change factors on several ecosystem functioning variables (i.e. photosynthetic efficiency, productivity, respiration and biomass) and how these effects could be shaped by the diversity and species identity of assemblages. CO2 alone or in combination with temperature affected the performance of macroalgae at both individual and assemblage level. In particular, high CO2 and high temperature (20°C) drastically reduced the biomass of macroalgal assemblages and affected their productivity and respiration rates. The identity of canopy species also played an important role in shaping assemblage responses, whereas species richness did not seem to affect such responses. Species belonging to the same functional effect group responded differently to the same environmental conditions. Data suggested that assemblages invaded with S. muticum might be more resistant in a future scenario of climate change. Thus, in a future scenario of increasing temperature and CO2 concentration, macroalgal assemblages invaded with canopy‐forming species sharing response traits similar to those of S. muticum could be favoured.

Green improved processes to extract bioactive phenolic compounds from brown macroalgae using Sargassum muticum as model

A comparative study between “alternative” extraction processes such as centrifugal partition extraction (CPE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) and classical solid/liquid used in the laboratory are currently focusing on the efficiency (selectivity and productivity) to obtain bioactive phenolic compounds from the phaeophyte Sargassum muticum model. The choice of the best process was based on several measurements: (i) the total phenolic content measured by the colorimetric Folin–Ciocalteu assay, (ii) radical scavenger and antioxidant activities assessed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, and the β-carotene bleaching method and finally (iii) the method productivity. Irrespective of the solvent used in the processes, alternative methods are always sharply more effective than classical ones. With the exception of SFE which does not allow extracting the totality of the active phenolic compounds, two of the other extraction methods were particularly promising. First, CPE afforded the most important yields in concentrated phenolic compounds (PC) (22.90±0.65%DW) also displaying the best activities (0.52±0.02 and 0.58±0.19mg/mL for IC50 and AAC700, respectively). Secondly, PLE using an EtOH:water mixture 75:25 (v/v) allowed a good PC extraction (10.18±0.25%DW) with huge efficiency. Despite a lesser activity of the extracts (0.77±0.01 and 1.59±0.15mg/mL for IC50 and AAC700, respectively) PLE is a green process and potentially complies European norms requirements for the prospective valorization of phenolic compounds from S. muticum in Brittany.

Mitochondrial cox3 and trnW-I sequence diversity of Sargassum muticum

The brown alga Sargassum muticum (Yendo) Fensholt, a component of the native algal flora of East Asia, is now one of the major macroalgal invaders of the coasts of North America and Europe. To investigate the genetic diversity of native populations, we analyzed mitochondrial cox3 and trnW-I from a total of 144 specimens of this species from Korea, Japan, as well as from North America, and Europe. A total of ten haplotypes were found in the concatenated cox3+trnW-I dataset: seven in western Korea, four in southern Korea, one each in eastern Korea and Jeju, one in Japan, and one each in Europe and North America. Haplotype 1 was common in Europe and North America, as well as in Korea. The number of private haplotypes, and haplotype and nucleotide diversities, were higher on the west coast of Korea than on the other coasts. No private haplotype was found in invaded areas. Thus, the west coast of Korea may be a native genetic diversity center.

Role of top-down and bottom-up forces on the invasibility of intertidal macroalgal assemblages

Despite the available information regarding the negative effects of non-indigenous species (NIS) on ecosystem structure and functioning, the mechanisms controlling NIS invasion remain poorly understood. Here, we investigated the relative roles of top-down and bottom-up control on the invasion of intertidal macroalgal assemblages by the macroalga Sargassum muticum (Yendo) Fensholt. Using a factorial experiment, nutrient availability and intensity of herbivory were manipulated along an intertidal rocky shore. We found that early recruitment of S. muticum was enhanced by low nutrient enrichment but no effect of grazers was observed. In contrast, at the end of the experiment (9-months after invasion) top-down control, together with the number of NIS and the percentage cover of ephemerals, was a significant predictor for the invasion success of S. muticum. In addition, both top-down and bottom-up forces played a significant role in structuring macroalgal assemblages, which indirectly could have influenced invasion success. Hence, by shaping community structure, main and interactive effects of bottom-up and top down forces may indirectly act on invasion. Our study highlights the importance of the recipient community structure on the invasion process and emphasizes the specific regulation of top-down and bottom-up forces in different stages of S. muticum invasion.

The invasive seaweed Sargassum filicinum (Fucales, Phaeophyceae) is on the move along the Mexican Pacific coastline

Abstract Sargassum filicinum Harvey is an important ecological engineer in the subtidal regions of northeastern Asian waters, as it forms marine forests that provide shelter for invertebrates and fishes. First discovered in Long Beach Harbor, CA, USA, in 2003, S. filicinum was thought to occur mainly in the California Channel Islands and near Ensenada, Mexico. However, during a survey from 2007 to 2009, we found S. filicinum off Isla Natividad, which is an extension of its range 550 km south of its last recorded location in the Mexican Pacific. Morphological and molecular data support the identification of the species. Considering its faster spread from Ensenada to Isla Natividad (4 years) than Sargassum muticum (14 years), S. filicinum may follow the path of S. muticum and arrive at the subtropical-tropical Pacific coast of Mexico. Although S. muticum has become well established within the local seaweed flora, S. filicinum may replace native Sargassum species and change the composition of local marine floras.

Comparative efficiency of macroalgal extracts and booster biocides as antifouling agents to control growth of three diatom species

The application of ‘booster biocides’ Diuron, Tolylfluanid and Copper thiocyanate inbantifouling paints, used to prevent development of biofouling, needs to be monitored before assessing their impacts on the environment. An alternative approach aims to propose eco-friendly and effective antifoulants isolated from marine organisms such as seaweeds. In this study, the effects of ‘booster biocides’ and the ethanol and dichloromethane extracts from a brown (Sargassum muticum) and a red alga (Ceramium botryocarpum) have been compared by algal growth inhibition tests of marine diatoms. The most efficient extracts were ethanol fraction of S. muticum and C. botryocarpum extracts with growth EC50=4.74 and 5.3μgmL−1 respectively, with reversible diatom growth effect. The booster biocides are more efficient EC50=0.52μgmL−1, but are highly toxic. Results validate the use of macroalgal extracts as non toxic antifouling compounds, and they represent valuable environmentally friendly alternatives in comparison with currently used biocides.

Effects of diet and density on growth, survival and gametogenesis of Hediste diversicolor (O.F. Müller, 1776) (Nereididae, Polychaeta)

The effects of diet and density on growth, survival and gametogenesis of the common ragworm Hediste diversicolor (Nereididae, Polychaeta) were investigated with the aim of contributing to define their optimal ranges in the context of a commercial farming system. Two different experimental trials were set up: in the first one, juveniles of H. diversicolor, obtained from laboratory cultures established with specimens taken from the Venice Lagoon, were fed according to three different food regimes (two based on commercial feeds and one consisting of an homogenate of the brown alga Sargassum muticum); in the second trial the juveniles were maintained at different rearing densities (300, 1000 and 3000ind. m−2). In both trials, the effects on growth, survival and gametogenesis were evaluated at various time-intervals during the eight-week period of the experiments. Results showed that H. diversicolor might be a promising species to be commercially exploited in an indoor farming system. In particular, high-protein diets permits elevated growth rates, earlier gametogenesis and sexual maturation. Both growth and survival rates were higher at the lowest densities, whereas the processes of gametogenesis and sexual maturation were not influenced by density.

Faunal differences between the invasive brown macroalga Sargassum muticum and competing native macroalgae

Interactions between macroalgae and their associated fauna are of great interest for marine invasions, because fauna may increase the biotic resistance of a system and macroalgal invasions may cause shifts in faunal composition. We tested for differences in faunal community structure between a macroalgal invader, Sargassummuticum, and several native macroalgae in intertidal pools on both the west and south coast of Portugal. On each coast, we compared the faunal diversity and composition associated with the invader with that of the competing native macroalga(e). On the west coast, the diversity of the fauna associated with S. muticum was equal to or lower than with the native competitor, Cystoseira humilis. Fauna composition differed between S. muticum and C. humilis at both locations, but within each species, no differences between locations were detected. In contrast, the fauna diversity on S. muticum of the south coast varied among locations. S. muticum fauna differed from the fauna of all native macroalgae at one location, but only from three out of seven native macroalgae at the other location. Discriminating fauna species did not show a consistent pattern towards higher or lower abundances in S. muticum compared to most native macroalgae, and species-specific contributions were small. Differences in fauna community also depended on the identity of the native macroalga. In conclusion, the fauna associated with S. muticum differs from many native brown macroalgae, but these differences were not consistent as they depend both on the native macroalgal species and on location. This invader does not seem to have a severe negative impact on local macroalgae-associated fauna.

Phenology, TPC and size-fractioning phenolics variability in temperate Sargassaceae (Phaeophyceae, Fucales) from Western Brittany: Native versus introduced species

The phenology of the introduced Sargassum muticum and two native species Bifurcaria bifurcata and Cystoseira baccata were monitored during eighteen months at two sites in Brittany. Density and length varied seasonally only in Sargassum. Larger individuals of Sargassum were observed in summer whereas in Cystoseira, they appeared almost in autumn. Peaks in maturity were delayed: in summer for Sargassum and in winter for Cystoseira and Bifurcaria. Phenolic contents increased before their respective reproductive period as a chemical defence. Moreover, size composition varied with site and season depending on species. In Sargassum, the quantity of small compounds decreased in summer together with an increase of 2000/5000 Da compounds. In Bifurcaria 2000/5000 Da compounds increased in summer (photoprotection) while in Cystoseira it increased in winter (protection for reproduction). Sargassum presented then a phenological plasticity not observed in native species. Moreover the three species possessed different chemical strategies to succeed in partitioning their vital space.

Evaluation of antifungal activity of seaweed extracts

Seaweeds are subject to numerous biological interactions and sometimes to extreme abiotic conditions, so they have developed among other defense mechanisms, the ability to produce biologically active substances. Thus, these organisms produce mainly terpenes and phenols. Among others, the antifungal activity, due to its importance in human and animal health and the production of agricultural products, has been the subject of several studies. In the present work, this activity was investigated in ten seaweeds extracts, by direct bioautography assays, compared to Colletotrichum lagenarium and disk diffusion assay, compared to Aspergillus flavus. The organisms studied were: Stypopodium zonale, Laurencia dendroidea, Ascophyllum nodosum, Sargassum muticum, Pelvetia canaliculata, Fucus spiralis, Sargassum filipendula, Sargassum stenophyllum, Laminaria hyperborea and Gracilaria edulis. S. zonale, L. dendroidea, P. canaliculata, S. muticum, A. nodosum and F. spiralis extracts significantly inhibited the C. lagenarium growth, but not inhibited significantly the A. flavus growth. The presence of terpenes in all of these extracts was confirmed by thin layer chromatography whereas the presence of phenolic compounds was confirmed only in extracts of P. canaliculata, A. nodosum and S. muticum. In chemical study by column chromatography, followed by gas chromatography/mass spectrometry analysis, the terpenes neophytadiene, cartilagineol, obtusol elatol; and the ester ethyl hexadecanoate were identified in the L. dendroidea extract. This is the first report on the activity of seaweed extracts against C. lagenarium, a fungus bearing agricultural importance.

Inhibitory Effect of Sargassum muticum (Yendo) Fensholt on Adipogenesis in 3T3-L1 Cells (44.29)

Abstract In this study, we investigated the ethanol extract of Sargassum muticum (Yendo) Fensholt (ESMF) inhibits adipocyte differentiation and expression of adipogenic marker genes, such as PPARγ (peroxisome proliferator activated receptor γ), C/EBPα (CCAAT-enhancer-binding protein α), GLUT4 (glucose transporter 4), adiponectin, aP2 (adipocyte fatty acid-binding protein 2) and ADD1/SREBP1c (adipocyte determination and differentiation factor 1/sterol regulatory element binding protein 1c) in 3T3-L1 cells. We demonstrated that ESMF induced a significant decrease in lipid accumulation and expression of adipogenic marker genes in a dose-dependent manner. In addition, ESMF reduced the transcripitional activity of PPARγ induced by troglitazone, a potent diabetes agent; it also suppressed expression of PPARγ and C/EBPα protein levels. Our findings provide that ESMF inhibits adipocyte differentiation through downregulation of various adipocytokines by blocking PPARγ and C/EBPα expression.

Apparent nutrient digestibility of seaweeds by rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus)

The apparent digestibility coefficients (ADCs) of four seaweeds, Porphyra dioica, Ulva spp., Gracilaria vermiculophylla and Sargassum muticum, were evaluated in rainbow trout and Nile tilapia. Porphyra, Ulva and Gracilaria were produced in land-based integrated multi-trophic aquaculture (IMTA). This production method resulted in increased protein content when compared to wild specimens and to the wild-harvested Sargassum. For both, trout and tilapia, the ADC of the experimental diets was generally lower than the reference diet, though in trout, protein digestibility of Gracilaria diet was similar to the reference diet (90%). In terms of the calculated seaweed ADC, the results vary significantly according to the seaweed and fish species. In trout, protein ADC of Gracilaria (88%) was significantly higher than all other seaweed (66–80%). Best lipid ADC was recorded for Gracilaria (97%), although not significantly different from Porphyra (94%). In tilapia, protein ADC was higher for Ulva (63.4%) and Sargassum (65.1%) than for the other seaweed. In lipid ADC, Gracilaria was significantly lower (82%) compared to all other test seaweed (91–95%). Overall trout seems to digest better Gracilaria, whereas tilapia does better with Ulva and Sargassum. The results demonstrate that IMTA-seaweed can be considered good ingredients for fish feed.

Hydrothermal fractionation of Sargassum muticum biomass

Sargassum muticum is an invasive brown alga which could be regarded as a renewable resource susceptible to fractionation and integral valorization. S. muticum biomass was processed according to a scheme consisting of conventional alkaline extraction of alginate, ultrafiltration to concentrate antioxidant compounds lost in the waste streams and autohydrolysis of the solid residue remaining after alginate extraction. The effect of temperature during non isothermal autohydrolysis was optimized to maximize yields and antioxidant activity of the solubilized fraction. The overall solubilization yield reached 88% of the initial material and the solubilization yield from the alginate-exhausted solid up to 82%. The waste fraction concentrated by membrane technology and that solubilized during autohydrolysis showed radical scavenging and reducing activities comparable to commercial antioxidants. The solid insoluble by-product from the autohydrolysis stage could be potentially useful for agricultural purposes.

Cr(VI) removal from synthetic and real wastewaters: The use of the invasive biomass Sargassum muticum in batch and column experiments

The macroalgae Sargassum muticum was selected for the treatment of solutions containing Cr(VI). Very acidic pH values were established as optimal for Cr(VI) reduction. Algae chemical modification reduced equilibrium time to 4h. First order kinetic model was used to describe the reduction kinetic of Cr(VI). A column experiment allowed to distinguish the processes occurring during Cr(VI) elimination: its reduction to Cr(III) and the subsequent adsorption of this species formed. Under the selected conditions the biomass was capable of reducing all the incoming Cr(VI) during 77h. Industrial wastewaters from chrome plating industry were also tested for chromium removal.