Marine Algae

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-binding capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroidtransforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, and uranium and also bind other heavy metals up to 25% of the biomass dry weight. Biosorption isotherm curves, derived from equilibrium batch sorption experiments, are used in the evaluation of metal uptake by different biosorbents. Further studies are focusing on the assessment of biosorbent performance in dynamic continuous-flow sorption systems. In the course of this work, new methodologies are being developed that are aimed a t mathematical modeling of biosorption systems and their effective optimization. Elucidation of mechanisms active in metal biosorption is essential for successful exploitation of the phenomenon and for regeneration of biosorbent materials in multiple reuse cycles. The complex nature of biosorbent materials makes this task particularly challenging. Discussion focuses on the composition of marine algae polysaccharide structures, which seem instrumental in metal uptake and binding. The state of the art in the field of biosorption is reviewed in this article, with many references to recent reviews and key individual contributions. A Bohumil Volesky is a Professor of Chemical Engineering a t McGill University (Montreal, Canada), active in areas of biochemical engineering and industrial water pollution control. He obtained his basic training a t the Czech Technical University in Prague, Czech Republic, receiving the Dipl. Ing. degree in 1962. Following more than 4 years of industrial research and experience, he earned his Ph.D. in biochemical engineering a t the University of Western Ontario (London, Ontario) in 1971. He is the founder and a president of BV Sorbex, Inc., a new technology venture commercializing the biosorption process for removal and recovery of heav metals from industrial solutions that he has been pioneering in his research. He has held appointments as a visiting professor a t the Swiss Federal Institute of Technology (Lausanne, Switzerland) and a t the University of Puerto Rico, and his major collaborative research activities include colleagues in China, Brazil, Korea, and the Czech Republic. His current research interests are reflected in a recently published book Biosorption of Heavy Metals that he edited and in a monograph volume Modeling and Optimization of Fermentation Processes. t 4

Recruitment is essential for the maintenance of populations, but far more is typically known about the more easily-observed adult stages than their smaller, often microscopic early life-history counterparts. This discrepancy can be particularly problematic for populations of foundation species that create biogenic habitat for a multitude of other taxa, but are themselves prime candidates for exploitation, fragmentation, and loss, and therefore become the focus of restoration eVorts partly or fully dependent on recruitment. The purpose of this study was to improve ecological understanding for early life-history stages of the habitat-forming marine alga Cystoseira barbata (Stackhouse) C. Agardh (Fucales: Sargassaceae), member of a genus that has experienced considerable fragmentation and population decline on European coasts. Using experimental manipulations of water temperature, light intensity, and sediment accumulation, we observed that sediment virtually precluded recruitment of C. barbata, and greatly impacted the survival of recently settled germlings (up to »83% mortality). Stronger intensities of light facilitated the growth of germlings, including the capacity for »50% of them to outgrow detrimental sediment and survive. Temperature (10 vs. 16°C) had no eVect on early recruitment, survival, or growth. This information helps to identify likely causes and locations of recruitment failure, and by extension, the conditions needed (either naturally or through human intervention) to facilitate recruitment and possible habitat restoration. Ultimately, this knowledge can increase our capacity to predict population persistence and the likely success of restoration eVorts. Communicated by S. D. Connell.

To examine the applicability of C/N and organic carbon stable isotope (δ 13 C) in studies of the Holocene sea level and freshwater discharge in the large river mouth of Yangtze, we observed the distribution of carbon, nitrogen and δ 13 C in a late-Quaternary core (ZK9) collected from the present subaqueous delta. We also collected published data of the two proxies for the suspended particulate matter (SPM) and surficial sediments from the lower Yangtze River to the adjacent East China Sea. The results show that the estuarine front is an important boundary for terrestrial and marine contribution of the organic component in the modern sedimentary environment. In the core ZK9, sediments deposited during c. 13-9 cal. ka BP are characterized by high values of TOC (0.54-1.16%), CaCO 3 (0.35% on average), and C/N (>12), which reflect an inner tidal estuarine environment dominated by C3 terrestrial organic carbon input. During c. 9-0.7 cal. ka BP, both TOC content (0.57% on average) and C/N ratio (<10) decrease remarkably while TN increases, indicating a lower estuarine or shallow marine environment. An abrupt sea level rise from c. 9 cal. ka BP resulted in a deeper water environment and reduced terrestrial input at the core location. The low δ 13 C values (−24.23‰ on average) before c. 6 cal. ka BP reflect a dominantly terrestrial source of organic matter associated with increased freshwater discharge into the estuary during that time. The sediments since c. 6 cal. ka BP are characterized by increasing δ 13 C up to −24.1 to −23.39‰, reflecting more contribution from marine algae as freshwater discharge fell. We suggest that in the Yangtze River mouth the C/N ratio indicates an abrupt sea level rise at c. 9 cal. ka BP, while δ 13 C is more useful in reflecting freshwater discharge.

The antioxidant activity of the marine algae G. changii from Malaysia was determined. The free radical scavenging activity of the 80% methanolic extract of G. changii was assessed with the aid of the stable DPPH (1,1-diphenyl-2-picrylhydrazyl) radical. The crude extract showed a low free radical scavenging capacities in comparison with commercial antioxidant BHT (butylated hydroxytoluene), and vitamin E. The IC 50 values of the extracts of algae on DPPH scavenging activity was 14.70 mg/ml. The TLC-DPPH study, exhibited only one DPPH radical scavenging bands out 7 major band of the extract and detected with R f value 0.63. In order to assess the role of polyphenolic components in the relevant activity, phenolic contents of the extract also determined and the value was 5.0 mg (gallic acid equivalent/1 g extract). This finding indicated that crude extract of G. changii was a starting material for the isolation of compound(s) with effective activities as radical's scavengers.

Recruitment is essential for the maintenance of populations, but far more is typically known about the more easily-observed adult stages than their smaller, often microscopic early life-history counterparts. This discrepancy can be particularly problematic for populations of foundation species that create biogenic habitat for a multitude of other taxa, but are themselves prime candidates for exploitation, fragmentation, and loss, and therefore become the focus of restoration eVorts partly or fully dependent on recruitment. The purpose of this study was to improve ecological understanding for early life-history stages of the habitat-forming marine alga Cystoseira barbata (Stackhouse) C. Agardh (Fucales: Sargassaceae), member of a genus that has experienced considerable fragmentation and population decline on European coasts. Using experimental manipulations of water temperature, light intensity, and sediment accumulation, we observed that sediment virtually precluded recruitment of C. barbata, and greatly impacted the survival of recently settled germlings (up to »83% mortality). Stronger intensities of light facilitated the growth of germlings, including the capacity for »50% of them to outgrow detrimental sediment and survive. Temperature (10 vs. 16°C) had no eVect on early recruitment, survival, or growth. This information helps to identify likely causes and locations of recruitment failure, and by extension, the conditions needed (either naturally or through human intervention) to facilitate recruitment and possible habitat restoration. Ultimately, this knowledge can increase our capacity to predict population persistence and the likely success of restoration eVorts.

Total phenolic content (TPC) and antioxidant activity (AOA) of 50% aqueous methanol extracts of the marine algae, Padina antillarum, Caulerpa racemosa and Kappaphycus alvarezzi were studied. TPC was measured using Folin-Ciocalteu method while 1, 1diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), ferrous ion chelating (FIC) assay and beta carotene bleaching (BCB) assay were used to study their AOA. P. antillarum was found to have the highest TPC, 24307208 mg gallic acid equivalents (GAE) per 100 g dried sample and ascorbic acid equivalent antioxidant capacity (AEAC), 1140785 mg AA/100 g. C. racemosa and K. alvarezzi displayed lower TPC and AEAC. C. racemosa had 144722 mg GAE/100 g dried sample of TPC and 14.372.0 mg AA/100 g of AEAC, while K. alvarezzi had 115735 mg/100 g dried sample of TPC and 37.8716.8 mg AA/100 g of AEAC.

Quorum sensing, bacterial cell-to-cell communication with small signal molecules such as acyl-homoserine lactones, regulates the virulence of many pathogenic bacteria. Therefore, interfering with quorum sensing is currently being explored as a novel biocontrol strategy to fight bacterial infections. In this study, the effects of 19 micro-algal strains on acyl-homoserine lactone-regulated phenotypes of three reporter strains were investigated. Two freshwater micro-algae inhibited violacein production of quorum sensing reporter strain Chromobacterium violaceum CV026. Further tests using Escherichia coli JB523 showed that micro-algal extracts inhibited or stimulated quorum sensing, depending on the algal strain. One freshwater and five marine algae showed quorum sensing inhibitory activity, whereas two algae stimulated quorum sensing-regulated gene expression. Micro-algal strains that showed inhibitory activity in the previous assays also inhibited acylhomoserine lactone-regulated bioluminescence in the aquaculture pathogen Vibrio harveyi. The growth of all reporter strains was found to be unaffected by the micro-algal samples. The most promising micro-algal strain was found to be Chlorella saccharophila CCAP211/48, as its extracts inhibited quorum sensing-regulated gene expression in all three reporter strains.

The adsorption of heavy metals onto biomaterial derived from the marine alga Ecklonia maxima was investigated via batch experiments. The adsorption equilibria of Cu, Pb and Cd could be represented by Langmuir isotherms and the capacity of fresh alga for Cu, Pb and Cd was approximately 85 -94, 227 -243 and 83.5 mg/g dry alga, respectively. The rate of adsorption onto the marine alga was high. The alga particle size played an important role in the adsorption behaviour. The coarse alga particles had a higher adsorption capacity and slower adsorption kinetics and could be regenerated without significant loss of capacity. In contrast, the fine alga particles had a lower adsorption capacity and faster adsorption kinetics and could not be regenerated without significant loss of capacity. Comparison with a commercial resin indicated that the activated biomass derived from E. maxima could be used as an efficient biosorbent for the treatment of waste waters containing heavy metals. D

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.

Though seaweed consumption is growing steadily across Europe, relatively few studies have reported on the quantities of heavy metals they contain and/or their potential effects on the population's health. This study focuses on the first topic and analyses the concentrations of six typical heavy metals (Cd, Pb, Hg, Cu, Zn, total As and inorganic As) in 52 samples from 11 algaebased products commercialised in Spain for direct human consumption (Gelidium spp.; Eisenia bicyclis; Himanthalia elongata; Hizikia fusiforme; Laminaria spp.; Ulva rigida; Chondrus crispus; Porphyra umbilicales and Undaria pinnatifida). Samples were ground, homogenised and quantified by atomic absorption spectrometry (Cu and Zn by flame AAS; Cd, Pb and total As by electrothermal AAS; total mercury by the cold vapour technique; and inorganic As by flame-hydride generation). Accuracy was assessed by participation in periodic QUASIMEME (Quality Assurance of Information in Marine Environmental Monitoring in Europe) and IAEA (International Atomic Energy Agency) intercalibration exercises. To detect any objective differences existing between the seaweeds' metal concentrations, univariate and multivariate studies (principal component analysis, cluster analysis and linear discriminant analysis) were performed. It is concluded that the Hizikia fusiforme samples contained the highest values of total and inorganic As and that most Cd concentrations exceeded the French Legislation. The two harvesting areas (Atlantic and Pacific oceans) were differentiated using both univariate studies (for Cu, total As, Hg and Zn) and a multivariate discriminant function (which includes Zn, Cu and Pb).

Nowadays marine algae are having a numerous commercial applications in various fields. Marine algae produce 60 trace elements in a concentration much higher than in terrestrial plants then the macroscopic marine algae also contain protein, iodine, bromine, vitamins and substances of stimulatory and antibiotic nature. This present study was summarized to the antimicrobial activity of the organic solvents of the Marine alage Padina tetrastromatica and phytochemical analysis of Padina tetrastromatica with various organic solvents such as Acetone, Ethanol, Ethyl acetate, Methanol and Tolune . The antibacterial activity against Bacillus subtilis, Proteus sp and Streptococcus sp in various solvents extracts of Padina tetrastromatica. The higher inhibitory activity was in Ethyl acetate extracts of Padina tetrastromatica and lesser inhibitory effect was in Acetone. The responsible functional groups in the solvent extract were identified by Fourier Transform Infrared (FTIR). Mostly marine algal products play a crucial role in various fields. May it's become even more diversified and economically competitive.

Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms). . . etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological novelty and diversity. Moreover, microalgae are considered as the actual producers of some highly bioactive compounds found in marine resources. Red algae are considered as the most important source of many biologically active metabolites in comparison to other algal classes. Seaweeds are used for great number of application by man. The principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in industry.

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 fungal biotechnology: an ecological perspective. Fungal Diversity 31: 19-35. This paper reviews the potential of marine fungi in biotechnology. The unique physico-chemical properties of the marine environment are likely to have conferred marine fungi with special physiological adaptations that could be exploited in biotechnology. The emphasis of this review is on marine fungi from a few unique ecological habitats and their potential in biotechnological applications. These habitats are endophytic or fungi associated with marine algae, seagrass and mangroves, fungi cohabiting with marine invertebrates, especially corals and sponges, fungi in marine detritus and in marine extreme environments. It is likely that microorganisms, including fungi may be the actual producers of many bioactive compounds reported in marine plants and animals. Fungi occurring in decomposing plant organic material or detritus in the sea have been shown to be source of several wood-degrading enzymes of importance in paper and pulp industries and bioremediation. One of the major applications of the thraustochytrids occurring in marine detritus and sediments is the production of docosahexaenoic acid (DHA), an omega-3 fatty acid used as nutraceutical. The deep-sea, an extreme environment of high hydrostatic pressure and low temperatures, hydrothermal vents with high hydrostatic pressure, high temperatures and metal concentrations and anoxic marine sediments are some of the unexplored sources of biotechnologically useful fungi. An understanding of the adaptations of extremotolerant fungi in such habitats is likely to provide us a greater insight into the adaptations of eukaryotes and an avenue from which to discover novel genes.

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&#39; 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). ...

Till date several methods of chemical synthesis of silver nanoparticles (AgNps) are known. Most of the protocol dealing with the chemical synthesis of AgNps involves high pressure, temperature, energy and technical skills. Thus, a method with much greener approach is the need of the hour. Accordingly, the authors have developed a method that is costeffective, energy-efficient and easy method for the synthesis of AgNps. The AgNps were synthesised by using white sugar and sodium hydroxide (NaOH) in the presence of sunlight. These nanoparticles were characterised by visual observation, ultraviolet-visible (UV-vis) spectrophotometry, Fourier transform infrared (FTIR), nanoparticle tracking and analysis (NTA) and transmission electron microscopy (TEM). The effect of NaOH on the rate of AgNps synthesis was also studied. Formation of AgNps was primarily detected by change in colour of reaction mixture from colourless to yellow after treatment with 1 mM silver salt (AgNO 3 ). UV-vis spectroscopy showed peak at 409 nm. NTA revealed the polydispersed nature of nanoparticles, 15-30 nm in diameter. FTIR showed the presence of gluconic acid as capping agent, which increases the stability of AgNps in the colloids. TEM demonstrated the presence of spherical AgNps in the range of 10-25 nm. The present method confirms the synthesis of AgNps by using white sugar and NaOH. This method is simple, eco-friendly and economically sustainable, making it amenable to large-scale industrial production of AgNps.

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.

The contents of total chlorophyll (T-Chl), carotenoids and phenolics compounds were quantified in the biomasses of Ulva lactuca grown either in normal or artificial sea water under indoor conditions. The antioxidant and antibacterial activities of U. lactuca crude organic extracts (Ulva-COEs) were determined. Thirty-four compounds in Ulva-COEs were characterised by thin layer chromatography and highperformance liquid chromatography. The major compounds were chlorophyll a (Chl a) (15.60-30.90%) and b (Chl b) (12.20-14.89%), 9-cis b-carotene (13.12-14.47%), a-carotene (11.44-11.47%) and all-trans bcarotene (6.16-29.70%, of total carotenoids).The Ulva-COEs exhibited remarkable antioxidant activity, with an IC 50 (concentration which causes a 50% of DPPH radical scavenging activity) values ranged from 16.5 and 18.7 lg mL )1 , which could be compared with the synthetic antioxidants: a-tocopherol (14.4 lg mL )1 ), butylated hydroxyanisol (13.1 lg mL )1 ) and butylated hydroxyltoluene (13.1 lg mL )1 ). Also, Ulva-COEs exhibited great potential antibacterial activities against six bacterial strains, with minimal inhibitory concentration values ranged from 0.40 to 0.35 mg mL )1 .

In order to survive in a highly competitive environment, freshwater or marine algae have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae are promising organisms to furnish novel biochemically active compounds. The current review describes the main substances biosynthesized by algae with potential economic impact in food science, pharmaceutical industry and public health. Emphasis is given to fatty acids, steroids, carotenoids, polysaccharides, lectins, mycosporine-like amino acids, halogenated compounds, polyketides and toxins.

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.

Present industrialization and global mobility era is an energy intensive period of the human history with an ever increasing energy demand. Unfortunately, fossil fuels are no more sustainable due to growing gap between the demand and supply. Biofuels are considered as promising alternative liquid fuels in recent global energy scenario. Food crops and ligno-cellulosic plant biomass have been widely studied as an alternative feedstock for biofuels production. After decades of research, the competition of fuel with food and recalcitrant nature of plant biomass, these feed stocks are losing their popularity. Marine macroalgae have come forward as another potential feedstock for biofuels production. Marine algae have several advantages over the traditional energy crops including absence of lignin, higher growth rates and no competition with human food. Moreover, along with several environmental benefits, they can be grown using saline and waste water and have higher abilities to sequester the atmospheric CO2 than traditional energy crops. Although there are several challenges associated with the algal biomass conversion to bioenergy yet these problems can be overcome using integrated biorefinery approach.

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.

Background: An interaction between lectins from marine algae and PLA 2 from rattlesnake was suggested some years ago. We, herein, studied the effects elicited by a small isolectin (BTL-2), isolated from Bryothamnion triquetrum, on the pharmacological and biological activities of a PLA 2 isolated from rattlesnake venom (Crotalus durissus cascavella), to better understand the enzymatic and pharmacological mechanisms of the PLA 2 and its complex.

Two new polyoxygenated steroids, namely, penicisteroids A and B (1 and 2), were obtained from the culture extract of Penicillium chrysogenum QEN-24S, an endophytic fungus isolated from an unidentified marine red algal species of the genus Laurencia. In addition, seven known steroids (3-9) were also isolated and identified. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configuration for compound 1 was determined by application of the modified Mosher's method. Penicisteroid A (1), which is a structurally unique steroid having tetrahydroxy and C-16-acetoxy groups, displayed potent antifungal and cytotoxic activity in the preliminary bioassays. Preliminary structure-activity relationships are discussed.

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.

A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro-and mesozooplankton and bacteria. The physical-chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive.