Brown Alga Sargassum Muticum Research Articles

Interaction of heavy metals with Ca-pretreated Sargassum muticum algal biomass: Characterization as a cation exchange process

The exchange mechanism taking place during elimination processes of different metal cations with natural biomass was analysed using the brown alga Sargassum muticum loaded with calcium. Sorption experiments varying initial metal concentration and kinetic studies have been performed. Cadmium and lead experiments have shown a 1:1 ratio between the amount of metal exchanged by the material and the calcium released back to the solution. This ratio was maintained for all metal concentrations. Based on the results it was concluded that cadmium elimination using the brown alga is mainly associated with an exchange process with calcium cations retained in the material structure. The analysis of kinetic data indicates that film diffusion is the rate limiting step in cadmium elimination process. On the other hand, the experiments carried out with mercury have shown varying ratios depending on the metal concentration, and more mercury was removed from solution than calcium was released back. Comparing mercury results with those of cadmium, it can be assumed that mercury elimination is not only associated with an exchange mechanism but also reduction is taking place. SEM and EDS analysis confirmed for the first time mercury reduction after batch sorption experiments.

Surface modifications of Sargassum muticum algal biomass for mercury removal: A physicochemical study in batch and continuous flow conditions

Mercury elimination onto brown alga Sargassum muticum has been studied in order to enhance process performance and to go further in the analyses of the combined sorption–reduction mechanism that is taking place. Several chemical treatments of the natural biomass have improved material stability and diminished weight losses, as it was confirmed through TOC analyses. Fast kinetics and high mercury removal capacities (0.9mmolg−1) were found with native and treated material. Competition with dyes has shown that mercury uptake is not affected for these organic compounds in solution; in addition, high metal and dye elimination percentages were obtained simultaneously in mercury/Methylene Blue mixtures. Column experiments have confirmed that mercury interaction with biomass is a complex mechanism where nearly 70% of the metal is reduced and 30% is adsorbed onto material surface.

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.

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.

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.

Anti-microfouling activity of lipidic metabolites from the invasive brown alga Sargassum muticum (Yendo) Fensholt.

The purification of the chloroform extract from the brown invasive macroalga Sargassum muticum, through a series of chromatographic separations, yielded 12 fractions that were tested against strains of bacteria, microalgae, and fungi involved in marine biofilm formation. The chemical composition of four (a, c, g, and k) out of the six fractions that exhibited anti-microfouling activity was investigated. Fraction a contained saturated and unsaturated linear hydrocarbons (C12-C27). Arachidonic acid was identified as the major metabolite in fraction c whereas fraction g contained mainly palmitic, linolenic, and palmitoleic acids. Fraction k was submitted to further purification yielding the fraction kAcaF1e that was composed of galactoglycerolipids, active against the growth of two of the four bacterial strains (Shewanella putrefaciens and Polaribacter irgensii) and all tested fungi. These promising results, in particular the isolation and the activity of galactoglycerolipids, attest the potential of the huge biomass of S. muticum as a source of new environmentally friendly antifouling compounds.

The extent of grazing release from epiphytism forSargassum muticum(Phaeophyceae) within the invaded range

The overall biotic pressure on a newly introduced species may be less than that experienced within its native range, facilitating invasion. The brown algaSargassum muticum(Yendo) Fensholt is a conspicuous and successful invasive species originally from Japan and China. We comparedS. muticumand native macroalgae with respect to the biotic pressures of mesoherbivore grazing and ectocarpoid fouling. In Strangford Lough, Northern Ireland,S. muticumthalli were as heavily overgrown with seasonal blooms of epiphytic algae as native macroalgal species were. The herbivorous amphipodDexamine spinosawas much more abundant onS. muticumthan on any native macroalga. When cultured with this amphipod,S. muticumlost more tissue than three native macroalgae,Saccharina latissima(Linnaeus) Laneet al.,Halidrys siliquosa(Linnaeus) Lyngbye andFucus serratusLinnaeus.Sargassum muticumcultured with both ectocarpoid fouling and amphipods showed a severe impact, consistent with our previous findings of large declines in the density ofS. muticumobserved in the field during the peak of fouling. Despite being a recent introduction into the macroalgal community in Strangford Lough,S. muticumappears to be under biotic pressure at least equal to that on native species, suggesting that release from grazing and epiphytism does not contribute to the invasiveness of this species in Strangford Lough.

Investigation of the antifouling constituents from the brown alga Sargassum muticum (Yendo) Fensholt

One of the most promising alternatives to toxic heavy metal-based paints is offered by the development of antifouling coatings in which the active ingredients are compounds naturally occurring in marine organisms and operating as natural antisettlement agents. Sessile marine macroalgae are remarkably free from settlement by fouling organisms. They produce a wide variety of chemically active metabolites in their surroundings, potentially as an aid to protect themselves against other settling organisms. In this study, a dichloromethane extract from the brown seaweed Sargassum muticum was tested in situ and, after 2 months of immersion, showed less fouling organisms on paints in which the extract was included, compared to paints containing only copper after 2 months of immersion. No barnacles or mussels have been observed on the test rack. Identification by NMR and GC/MS of the effective compound revealed the abundance of palmitic acid, a commonly found fatty acid. Pure palmitic acid showed antibacterial activity at 44 µg mL−1, and also inhibited the growth of the diatom Cylindrotheca closterium at low concentration (EC50 = 45.5 µg mL−1), and the germination of Ulva lactuca spores at 3 µg mL−1. No cytotoxicity was highlighted, which is promising in the aim of the development of an environmentally friendly antifouling paint.

Study on sterols from brown algae (Sargassum muticum)

Various Δ5-3β-sterenols, whose carbon numbers range from C19-C23 to C26-C30 and some compounds have many stereomers maximal up to six, have been detected out from the extract of brown algae (Sargassum muticum), which means that steranes with lower carbon numbers are likely different in the origin, and some corresponding sterol stereoisomers may have already existed in their precursor organisms. This provides some experimental evidence for supplementing and amending the traditional interpretation of the sterol stereoisomer transformation during the deposition and diagenesis of organic matter.

GENOMIC DNA ISOLATION FROM GREEN AND BROWN ALGAE (CAULERPALES AND FUCALES) FOR MICROSATELLITE LIBRARY CONSTRUCTION1

A method for isolating high‐quality DNA is presented for the green algae Caulerpa sp. (C. racemosa, C. prolifera, and C. taxifolia) and the brown alga Sargassum muticum. These are introduced, and invasive species in Europe, except for the native C. prolifera. Previous methods of extraction, using cetyl trimethyl ammonium bromide or various commercial kits, were used to isolate genomic DNA but either no DNA or DNA of very low quality was obtained. Genomic libraries were attempted with Caulerpa sp. on three occasions and either the restriction enzyme, the Taq polymerase, or the T4 ligase was inhibited, probably by the large amount of polysaccharides in these algae. The method presented here consists of the rapid isolation of stable nuclei, followed by DNA extraction. Yields of 6–10 μg genomic DNA from 1 g fresh blades were obtained. After genomic DNA was isolated from fresh material, the quality was checked by agarose gel. Quantification of DNA concentration was performed using UV spectrophotometric measurement of the A260/A280 ratio. The DNA was suitable for PCR, cloning, and hybridization. The DNA isolated using this method allowed successful construction of microsatellite libraries for Caulerpa species and S. muticum. The technique is inexpensive and appropriate for the isolation of multiple samples of DNA from a small amount of fresh material.

Epiphytic macroalgae on the introduced brown seaweed Sargassum muticum (Yendo) Fensholt (Phaeophyceae) in Norway

The invasive brown alga Sargassum muticum was first observed growing attached in Norway in 1988. Since then, the species has spread rapidly and is now an established member of the algal community in sheltered areas along the entire Skagerrak coast. In 1999, one population in the outer Oslofjord was investigated for epiphytic macroalgae, and evidence was found of a rich macroalgal community on S. muticum. A total of 82 different algal taxa were identified: 34 rhodophytes, 23 phaeophytes and 25 chlorophytes. The epiphytes found on S. muticum included more than 25% of the total number of algal species found in the Oslofjord area. A summary of all species recorded is given, with floristic notes on particular taxa.

Non-native Species and Rates of Spread: Lessons from the Brackish Baltic Sea

The Baltic Sea, a semi-enclosed brackish water region, has been inoculated by non-indigenous species for centuries. Today, much of its biological diversity is of foreign origin (i.e. xenodiversity), intentionally or unintentionally moved by humans over ecological and geographical barriers. As many as 98 introduced species have been recorded in the Baltic Sea and Kattegat. The role and abundance of much of the unique native brackish water fauna of the Baltic Sea are threatened by these non-indigenous species. The rate of primary introductions into the Baltic has increased since the 1950s; the secondary rate of spread of non-indigenous species within the basin varies from 30–480 km/year. We review here the invasion histories of the brown alga Sargassum muticum (introduced in the early 1990s), the mud snail Potamopyrgus antipodarum (1887), the barnacle Balanus improvisus (1844), the polychaetes Marenzelleria viridis (1985) and Polydora redeki (1963), the cladoceran Cercopagis pengoi (1992) and the mysid shrimp Hemimysis anomala (1962).

Mobile epifauna inhabiting the invasive Sargassum muticum and two local seaweeds in northern Spain

The mobile epifauna colonizing the invasive brown alga Sargassum muticum (Yendo) Fensholt was compared with assemblages inhabiting two locally established seaweeds ( Fucus vesiculosus L. and Cystoseira nodicaulis (Whit.) Roberts) in a sheltered locality of northern Spain. The epifauna colonizing S. muticum was studied in both the shallow subtidal and intertidal pools at mid shore. The main aims of this study were to: (i) determine the host-plant specificity of the mobile epifauna; (ii) estimate the impact of the invasion on these animal assemblages. The mobile epifauna was not highly host-plant specific; very few taxa were found in just one algal species. Herbivorous species (mesograzers) were very abundant, accounting for 58–98 % of the characterized epifauna. Sargassum muticum was successfully colonized by the assemblages inhabiting local seaweeds, and this was probably due to: (i) the presence of epifaunal species that use plant epiphytes as habitat and food rather than the macroalga itself; (ii) morphological and chemical similarities between the invasive and the local seaweeds; (iii) generalist habits of mesograzers consuming the host plant itself. The impact of S. muticum invasion on the epifauna depends on the degree of host-plant specificity of animals as well as on the effect of the invader on macroalgal assemblages. The results of this study support the existence of a labile association between seaweeds and the invertebrates inhabiting them.

Historical changes and inventory of macroalgae from Königshafen Bay in the northern Wadden Sea

Knowledge on the distribution, abundance and species richness of intertidal macroalgae occurring on sandy and muddy flats of the German Wadden Sea is still incomplete. We summarize published and unpublished information available on the presence of macroalgae on the tidal flats of Konigshafen Bay (island of Sylt, North Sea), one of the more extensively studied areas of the Wadden Sea. A total of 46 green algal species, 36 brown algal species and 26 red algal species has been recorded within the last 120 years on soft and hard substrata of Konigshafen Bay (disregarding species found unattached or drifting). Several of these species were only temporarily resident on the tidal flats. Today, at least 35 green, 15 brown and 12 red algal species occur within or close to Konigshafen Bay. Significant long-term changes in species abundances have occurred in all three major groups of algae: Since the late 1970s, dense green algal mats dominated byEnteromorpha flexuosa, E. radiata andE. prolifera have occurred regularly on the intertidal flats, whereas a general decrease of brown and red algae has been documented. Two red algal species,Gracilaria verrucosa and its epiphyteCallithamnion corymbosum, were conspicuous members of the macroflora until the middle of this century. Although still present in the 1980s, they have now disappeared completely. On the other hand, the brown algaSargassum muticum has begun to colonize mussel beds. The causal background of long-term changes in the macroalgal flora of Konigshafen Bay is discussed. Owing to substantial nomenclatural changes during the last 120 years, a revised species list with authors’ names and synonyms is included.

Receptacle regeneration in Sargassum muticum (Phaeophyta)

Receptacle regeneration in the adventive marine brown alga Sargassum muticum (Yendo) Fensholt (Fucales, Phaeophyta) is examined using light and electron microscopical (SEM, TEM) techniques and laboratory culture studies. After transverse bisection, receptacle regeneration occurred under a wide range of temperatures and at different daylengths but was inhibited under winter conditions (10°C, 8:16 h). Regeneration is a particularly rapid process with mature, zygote-bearing receptacles formed at the cut surface within 21 d at 20°C, 16: 8 h and 88 μmol photons m−2 s−1. Cytological and morphogenetic changes observed after wounding include: the breaking of intercellular plasmodesmatal connections; retraction of cytoplasm and deposition of new fibrillar material beneath the exposed degenerating cell walls, preventing cytoplasmic loss; the formation of a protective wound epidermis over the entire cortical wound surface by finite mitoses in the outermost cell layer; concurrent mitoses to a depth of at least four cells beneath the medullary wound which continue to form a protruding meristematic mound; the development of apical initial cells within the regenerative mound, several of which give rise to new receptacles. Observations on receptacles cut at different points along their length reveal that basal wounds regenerate more slowly than apical wounds, the intact receptacle apex exerting a dominance effect that inhibits regeneration.

Life-Cycle and Its Control of Sargassum muticum (Phaeophyta) in Batch Cultures.

An experimental study was made of the life cycle of a large-sized brown alga Sargassum muticum and its control using simple batch cultures in order to establish a routine system of supplying embryos as materials for laboratory experiments. Growth of early germlings was faster at higher temperatures under a long-day condition (15h L). On the other hand, main branch elongation was promoted under a short-day condition (9h L). Under the long-day condition, growth of leaves was active while main branch elongation was very poor. Under the short-day condition, main branches extented to form vesicles. Receptacle formation was observed by transferring the thalli grown and differentiated under the short-day condition at 10-15°C to the long-day condition at 20°C. Fertilized eggs repeated cell divisions to form early embryos on receptacles. The embryos were then liberated to the bottom of culture vessels and grew into normal thalli. By controlling temperatures and photoperiods, it became possible to regulate the growth and differentiation of the species, which brought a small thallus only 5.6cm high into fertility.

Studies on the Recently Introduced Brown Alga Sargassum muticum (Yendo) Fensholt. V. Receptacle Initiation and Growth, and Gamete Release in Laboratory Culture

Article Studies on the Recently Introduced Brown Alga Sargassum muticum (Yendo) Fensholt. V. Receptacle Initiation and Growth, and Gamete Release in Laboratory Culture was published on January 1, 1990 in the journal Botanica Marina (volume 33, issue 3).

Studies on the Recently Introduced Brown Alga Sargassum muticum (Yendo) Fensholt

The growth rates of germlings of the large, introduced, brown alga Sargassum muticum (Yendo) Fensholt, collected from Bembridge, Isle of Wight, south coast of England, are described under different conditions of temperature, irradiance and salinity

Presence and development of populations of the introduced brown alga Sargassum muticum in the southwest Netherlands

Presence and development of populations of the introduced brown alga Sargassum muticum in the southwest Netherlands

Sargassum muticum begin to invade the mediterranean

In the Mediterranean, the Japanese brown alga Sargassum muticum (Yendo) Fensholt is no longer confined to the relatively closed Thau lagoon (France), but is spreading along the Languedoc open-sea coasts: 11 new localities, from Grau du Roi (Gard) to Port-la-Nouvelle (Aude), are mentioned.