Marine Algae

The objective of the present study was to assess the effect on nutritional value and hardness due to inclusion in multinutritional blocks (MB) of marine vegetation, molasses, urea and calcium hydroxide (CaOH). Marine vegetation was gathered at the coast of Yucatán. This material was rinsed with fresh water and sun dehydrated. MBs were manufactured including 9.5 % of marine vegetation, plus soybean hulls meal, ground corn, molasses, calcium orthophosphate, salt, vegetable oil and a mixture of minerals and vitamins; calcium hydroxide was added as agglutinant. A factorial 3*2*3 experimental design with three replicates was used, where molasses 35.0, 37.5 and 40.0 %; urea 6 and 9 % and CaOH 5, 7 and 9 % were factors and levels. Hardness (kg maximum pressure) of BMs was measured using a 4411 Universal Testing Machine (Instron). Results were analyzed through the least square method, including effects of the already mentioned factors and their interactions. Results showed that marine veget...

Silver nanoparticles were successfully synthesized using crude neem leaf (Azadirachta indica) extract at room temperature. The formation and crystallinity of synthesized silver nanoparticles was confirmed by X-Ray diffraction (XRD) pattern. The average size of these silver nanoparticles is about 20-50 nm as observed by Transmission electron microscopy (TEM) images. Optical absorption measurements were performed to determine band-edge energy gap of these silver nanoparticles. Photoluminescence (PL) studies were performed to emphasize its emission properties. The synthesized silver nanoparticles could have major applications in the area of nanoscale optoelectronics devices and biomedical engineering. Our synthesis method has advantage over other conventional chemical routes because it is cost effective & environmental compatibility.

Enteromorpha compressa (L.) Nees was identified from sea habitat during the taxonomic investigation of marine filamentous green algae in 2016 at Bakkhali in South 24 Parganas district, West Bengal, India. The thallus is light green, branched, crispate and vegetative cells are variables in sizes and thick walled. The species was found abundant mostly during winter (December-February) to early summer (March) in the water column as attached benthic form. It preferred to grow in sunny places. This is the first report from West Bengal, India.

Red seaweeds were investigated, using SCUBA, from waters around the island of Cozumel off the east coast of the Yucatan Peninsula in Mexico. One hundred and eighteen species of Rhodophyta were collected and identified. Forty-five of these are reported for the first time from Cozumel, and of these 11 are new records for Mexico. There was a distinct change in the deep water flora between wet and dry seasons; the dry season had more species with northern ranges in comparison with the flora in general. The wet season had few north-ranging species. Fifty-four epiphytic or hemiparasitic species were identified, most frequently on Halimeda tuna, Dictyota cervicornis and Sargassum spp. This account brings the total mac-roalgal taxa reported from Cozumel to 385, the richest flora of any locality in the Caribbean region of Mexico.

In the study of benthic marine algae of the reefs formation from Todos os Santos Bay, one chlorophyte (Caulerpa brachypus Harv.) and four rhodophytes [Champia vieillardii Kütz., Ceramium flaccidum (Kütz.) Ardiss., Ceramium vagans P.C. Silva, Polysiphonia denudata (Dillwyn) Grev. ex Harv. in Hook.] are cited as new records to the Bahia State, three rhodophytes [Ceramium deslongchampii Chauv. ex Duby, Polysiphonia scopulorum Harv. and Neosiphonia tongatensis (Harv. ex Kütz.) Kim & Lee] are cited as new records to northeastern Brazil and one rhodophyte [Ceramium cimbricum H.E. Petersen in Rosenv. f. flaccidum (H.E. Petersen) Furnari & Serio in Cecere et al.] is refereed for the first time to the Brazilian coast. In this work, comments about taxonomic characteristics, habitat and geographical distribution of these taxa were presented.

Tuke Mak’lang Beach Resort has a seagrass bed with a muddy, rubbles and sandy substrate composing of two seagrass families, viz. Potamogetonaceae (2 genera, 2 species) and Hydrocharitaceae (3 genera, 3 species). Surface and bottom temperatures of the assessed site are 30.6°c and 29°c respectively. Salinity of the surface water was 35 ppt and bottom salinity was 35.5 ppt while the pH level is 7.2. Syringodium isoetifolium yields the greatest frequency (70.83%), relative frequency (37.0%), density (41.86%) , most dominant (78.46%)and percent cover (40.3%) respectively in sea grass assessment. On the other hand, as a result of seaweed assessment, Padina minor yields the greatest frequency (79.17%), relative frequency (26.02%) and relative density (53.85 %) in sea weeds assessment. Padina minor (42.2%) has the highest percent cover while G. verricosa (2.73%) has the lowest percent cover. In addition it is also the most dominat species of seaweeds.

Marine algae have attracted a great deal of interest as excellent sources of nutrients. Polysaccharides are the main components in marine algae, hence a great deal of attention has been directed at isolation and characterization of marine algae polysaccharides because of their numerous health benefits. In this review, extraction and purification approaches and chemico-physical properties of marine algae polysaccharides (MAPs) are summarized. The biological activities, which include immunomodulatory, antitumor, antiviral, antioxidant, and hypolipidemic, are also discussed. Additionally, structure-function relationships are analyzed and summarized. MAPs' biological activities are closely correlated with their monosaccharide composition, molecular weights, linkage types, and chain conformation. In order to promote further exploitation and utilization of polysaccharides from marine algae for functional food and pharmaceutical areas, high efficiency, and low-cost polysaccharide extra...

... 2346–2353. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (355). [7] S. Sharma, N. Ahmad, A. Prakash, VN Singh, KA Ghosh and BR Mehta, Mater Sci Appl 1 (2010), pp. 1–7. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (0). ...

Laminaria is a kelp that finds its place in the brown algae family. It has been an area of study for past many years, and its wonderful biological properties have always attracted medical professionals and researchers to explore more and more from this wonder kelp. The constituents of Laminaria include iodine, potassium, magnesium, calcium and iron. Iodine compounds, TEA-hydroiodide in particular, are great lipolytic agents as they stimulate lipase activity. Laminarins on the other hand are used as a tumor angiogenic blocker. This genus of the kelps is also rich in algin, a high molecular weight polysaccharide that forms viscous colloidal solutions or gels in water leading to the use of kelp derivatives as bulk laxatives. It has great applications in cosmeceutical science, as well as some antibacterial properties have also been assigned to Laminaria. A deeper insight into the physical, biological, and chemical properties of this wonder kelp would lead to further exploitation of Laminaria for medicinal and cosmeceutical purpose.

We evaluated the structure of planktonic communities and paleoenvironmental conditions throughout the Cenomanian–Turonian Oceanic Anoxic Event (OAE2) by studying bulk geochemical properties and the molecular isotopic composition of source-specific hydrocarbons from organic-rich sediments deposited in an intrashelf basin at the Levant Platform, central Jordan. High concentrations of desmethyl and 4-methylsteranes as well as dinosteranes indicate that marine algae including dinoflagellates were the main primary producing organisms. The presence of 2-methylhopanes and 13C-enriched hopanes, in addition to isotopically enriched aryl isoprenoids, evidenced the contribution of cyanobacteria and green sulfur bacteria, respectively. Additionally, variable but fairly low δ15N values during OAE2 suggest the occurrence of diazotrophy as a likely important process fueling primary production during OAE2 in this stratified/anoxic continental platform. Variations in the relative contribution of biomarkers revealed changes in planktonic communities associated with sea level change and water column stratification. OAE2 was characterized by strong stratification, anoxic bottom waters and a deep chemocline, as evidenced by high gammacerane and homohopane indices and the absence of photic zone euxinia (PZE) markers, respectively. However, the presence of isorenieratane and its derivatives in post-OAE black shales points to a shoaling of the chemocline and to PZE. This interval was also characterized by an exceptionally high abundance of chlorophyll-derived pristane and phytane (up to 2 mg g−1 TOC), likely as a result of highly enhanced primary production and organic matter preservation. Remarkably, this high productivity event co-occurs with an exceptionally high abundance of calcispheres reported elsewhere to be part of a global bio-event.

The Abrolhos Bank, located on the coast of Bahia, Brazil, harbors the largest coral reef system in the South Atlantic. This area has attracted the attention of biologists because of its peculiar mushroom-shaped structures, locally known as “chapeirões”, and endemic species of corals and other organisms. The macrophytobenthos compartment plays an important ecological role in the functioning of the bank,
and some reports on the presence of seaweeds and seagrasses have been published; however, the data are fragmentary, and a more detailed survey of the macrophytobenthos compartment is lacking. Here we consolidate the information available and add new data obtained from two expeditions focused on
seaweed and seagrass diversity from two sectors of the bank: the islands of the Abrolhos archipelago (AA) and the Sebastião Gomes Reef (SG). These sites were selected for their contrasting characteristics. Specifically, SG (15 km off the mouth of the Caravelas River) is subjected to a broader range of anthropogenic impacts and to input of terrigenous sediments, while the AA (54 km offshore) is surrounded by calcareous biogenic sediments, has clearer water and is less affected by human activities. Macrophytobenthic species richness on both reference areas is larger than previously thought. Considering previous records, there are 164 species of macrophytes in AA and 111 species in SG, of which 59 and 74 species arefirst records for each respective location. The higher species richness at the AA may result from a higher habitat complexity and lower turbidity, but a potential negative effect of enhanced human impacts at SG cannot be ruled out. Considering that macroalgae are relevant components of the benthic community, as producers and structurer organisms, the data presented herein provide a reliable baseline for future environmental studies, and thus may contribute to improve
management policies within the unique ecosystem of Abrolhos

The chemical composition, amino acid, and element contents, as well as some physicochemical properties of Ulva
pertusa and U. intestinalis, collected from the Pattani Bay in Southern Thailand in the rainy and summer seasons of 2007–
2008, were investigated in order to gain more nutritional information. It was found that the two green seaweed species
contained high level of protein (14.6–19.5% DW), lipid (2.1–8.7% DW), ash (25.9–28.6% DW), soluble fiber (25.3–39.6% DW),
insoluble fiber (21.8–33.5% DW) and total dietary fiber (51.3–62.2% DW). Comparing the element contents of the two species,
U. pertusa was rich in Mg, K and Ca, while U. intestinalis was rich in Mg, K, Cl, Na, and Ca. The essential amino acids of the
two species were rich in leucine, valine, and arginine contents. The most limiting essential amino acid of both species was
lysine. However, the nutritional composition of the two seaweeds varied depending on seasonal change. As for the physicochemical
properties of both seaweeds, their swelling capacity (SWC), water holding capacity (WHC), and oil holding capacity
(OHC) ranged from 4.0 to 6.4 ml/g DW, 7.8 to 15.0 g/g DW and 1.4 to 4.8 g oil/g DW, respectively. WHC and OHC of U.
intestinalis was higher than those of U. pertusa (P<0.05). This study suggested that both species could be potentially used
as raw materials or ingredients to improve the nutritive value and texture of functional food and healthy products for human
beings.

Se examinó la distribución estacional de las macroalgas marinas y las variables de los microhabitats (temperatura, salinidad, pH, oxígeno disuelto y tipo de sustrato) en dos áreas Naturales Protegidas de la costa Norte de la
Península de Yucat{n, de noviembre de 2005 a julio de 2006. Se muestrearon seis estaciones en el Palmar y cuatro en Dzilam. Se registraron un total de 64 especies, 54 para El Palmar y 45 para Dzilam. La similitud entre las dos ANP´s resultó baja (< 50 %). La mayor abundancia en El Palmar se presentó durante la época de seca-fría, mientras que en Dzilam fue en la de
lluvias. Las condiciones ambientales entre las localidades fueron semejantes y lo que varió fue el sustrato, por lo que se considera que el par{metro que condiciona la presencia de las especies en estas zonas es el tipo de sustrato disponible para su fijación.

ABSTRACT
We examined the seasonal distribution of the marine macroalgae and their microhabitats variables (temperature, salinity, pH, dissolved oxygen, and substrate type)
in two Natural Protected Areas (NPAs) off the northern coast of the Yucatan Peninsula.
From November 2005 to July 2006, we sampled macroalgae at six stations
in El Palmar and four stations in Dzilam. It was collected 64 species, 54 in El Palmar and 45 in Dzilam. Similarity was low (< 50%.). The higher abundance of species in El Palmar was presented during the dry-cold (nortes) season, while in Dzilam was during the rainy season. While most of the environmental conditions were similar among sites, the type of substrate was the variable that appeared to influence the presence of macroalgae species.

Seventy-three species of macroalgae from the Mexican Pacific, Atlantic and Caribbean coast were screened for ichtyotoxic activity. Ethanolic, acetonic and aqueous extracts were prepared and tested against the fish Carassius auratus. The extracts were classified on the basis of their effects as: toxic if the fish died in two hours or less; moderately toxic, if the organism behaved abnormally but death did notoccur, and non-toxic if the fish did not display any change. 79% species were ichtyotoxic to some degree. Extracts of 39 species were toxic, with at least one extract with lethal effects, 19 were moderately toxic and 15 species were non-toxic. Only the extracts ofDictyota bartayresiana, Dictyota cervicornis,Lobophora variegata, Bryothamnion triquetrum and Laurencia obtusa were toxic in all three solvents. The acetone and ethanol extracts were more active, and therefore are more suitable for extraction of toxic substances.

The composition and structure of polysaccharides from several groups of calcareous algae (including calcareous cyanobacteria), which differ in the calcification mode (extracellular, cell wall, or intracellular), are reviewed. Two families of marine algae, Corallinaceae (Rhodophyta) and Cocolithophoraceae (Prymnesiophyta = Haptophyta), are considered in detail; they exhibit the cell wall and intracellular calcification modes, respectively, and synthesize unusual polysaccharides that seem to directly participate in the calcification process.

Edible seaweed products have been used in many countries, specifically Japan, as a food item. Recently these products have become popular in the food industry because of a number of interesting medicinal properties that have been associated with certain edible marine algae. Very little control exists over the composition of these products, which could be contaminated with a number of agents including heavy metals and certain radioactive isotopes. Fifteen seaweed samples (six local samples from the coast of British Columbia, seven from Japan, one from Norway and one undisclosed) were obtained. All samples were analyzed for multiple elements, using ICP mass spectrometry and for radioactive constituents. It was found that six of eight imported seaweed products had concentrations of mercury orders of magnitude higher than the local products. Lead was found at somewhat higher concentrations in only one local product. Laminaria japonica had the highest level of iodine content followed by Laminaria setchellii from local sources. Only traces of cesium-137 were found in a product from Norway and radium-226 was found in a product from Japan. Arsenic levels were found to be elevated. In order to estimate the effect of these levels on health, one needs to address the bioavalability and the speciation of arsenic in these samples.

In this research, have been studied marine algae in the upper infralittoral zone of the Bosphorus coasts of İstanbul (including Bosphorus) . A total of 244 taxon have been determined. 11 of them belong to blue-green bacteria (Cyanophyta), 127 to red algae (Rhodophyta), 46 to brown algae (Heterokontophyta), 60 to green algae (Chlorophyta) and 2 to flowering plants (Tracheophyta).

To Cite This Article: Raghda R. S. Hussein, Ahmad A. Farghali, Ahmed H. A. Hassanein, Ibraheem B.M. Ibraheem Biosynthesis of silver nanoparticles by using of the marine alga Gracilaria parvispora and its antagonistic efficacy against some common skin infecting pathogens Aust. Biosynthesis of nanoparticles (NPs) is a growing field, the intersection of nanotechnology and biotechnology has attracted a lot of attention due to the growing need to develop environmentally safe and effective technologies in material synthesis. Synthesis of silver nanoparticles (AgNPs) using the marine alga Gracilaria parvispora extract is clearly shown here. Transmission electron microscopy (TEM) revealed that the prepared AgNPs are spherical shaped with size range of 12–30 nm. Fourier Transform Infrared Spectroscopy (FTIR) showed that AgNPs were capped and stabilized in solution with algal bioactive compounds. Moreover, the antimicrobial activity of the algal extract alone and with the produced AgNPs has been addressed with certain bacteria and fungi to reveal the benefit of produced AgNPs for making antibacterial and antifungal pharmaceutical topical in future.