Search results for "algae"
showing 10 items of 403 documents
Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian c…
2013
Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper …
Sunscreen Products as Emerging Pollutants to Coastal Waters
2013
A growing awareness of the risks associated with skin exposure to ultraviolet (UV) radiation over the past decades has led to increased use of sunscreen cosmetic products leading the introduction of new chemical compounds in the marine environment. Although coastal tourism and recreation are the largest and most rapidly growing activities in the world, the evaluation of sunscreen as source of chemicals to the coastal marine system has not been addressed. Concentrations of chemical UV filters included in the formulation of sunscreens, such as benzophehone 3 (BZ-3), 4-methylbenzylidene camphor (4-MBC), TiO2 and ZnO, are detected in nearshore waters with variable concentrations along the day a…
Aquaculture and its by-products as a source of nutrients and bioactive compounds
2020
Underutilized marine resources (e.g., algae, fish, and shellfish processing by-products), as sustainable alternatives to livestock protein and interesting sources of bioactive compounds, have attracted the attention of the researchers. Aquatic products processing industries are growing globally and producing huge amounts of by-products that often discarded as waste. However, recent studies pointed out that marine waste contains several valuable components including high-quality proteins, lipids, minerals, vitamins, enzymes, and bioactive compounds that can be used against cancer and some cardiovascular disorders. Besides, previously conducted studies on algae have shown the presence of some…
Robust Mesoporous CoMo/γ-Al2O3 Catalysts from Cyclodextrin-Based Supramolecular Assemblies for Hydrothermal Processing of Microalgae: Effect of the P…
2018
Hydrothermal liquefaction (HTL) is a promising technology for the production of biocrude oil from microalgae. Although this catalyst-free technology is efficient under high-temperature and high-pressure conditions, the biocrude yield and quality can be further improved by using heterogeneous catalysts. The design of robust catalysts that preserve their performance under hydrothermal conditions will be therefore very important in the development of biorefinery technologies. In this work, we describe two different synthetic routes (i.e., impregnation and cyclodextrin-assisted one-pot colloidal approach), for the preparation in aqueous phase of six high surface area CoMo/γ-Al2O3 catalysts. Cat…
The effect of Ruppia cirrhosa features on macroalgae and suspended matter in a Mediterranean shallow system
2006
Relationships among chemical–physical features, total gross suspended organic matter, coverage of the seagrass Ruppia cirrhosa and its associated algal community in eight ponds of a saltworks system of western Sicily (Mediterranean Sea) were investigated in spring and summer 2004. All biological features varied both at different levels of seagrass coverage and between seasons. A low algal diversity (46 taxa, 14.75 ± 1.41 on average) was highlighted; algal coverage and species richness showed to be negatively correlated. Ruppia cirrhosa coverage was negatively correlated with algal coverage, but positively correlated with species richness. Moreover, a significant correlation among R. cirrhos…
The first colonization of the Genus Amphistegina and other exotic benthic foraminifera of the Pelagian Islands and south-eastern Sicily (central Medi…
2014
Abstract A detailed study of the marine sediments collected on the inner shelf of some of the selected areas of the central Mediterranean Sea has been carried out in order to verify the presence of exotic benthic foraminiferal species. Since 2000, the coastal marine environments of the Pelagian Islands and of Sicily (central Mediterranean) have been increasingly colonized by exotic species (i.e. fishes and algae) originating both from the Atlantic Ocean and the Red Sea. The studied areas (Pelagian Islands and SE Sicily) are located in the middle of the Mediterranean Sea. Therefore, they represent an ideal place to understand how exotic species, coming from different Oceans, may have coloniz…
Effects of temperature, salinity and food level on the life history traits of the marine rotifer Synchaera cecilia valentina, n. subsp.
1997
A strain of the marine rotifer Synchaeta cecilia valentina, n. subsp., isolated from the Hondo of Elche Spanish Mediterranean coastal lagoon at 22%o salinity, was cultured in the laboratory in 20 ml test tubes and fed with the alga Tetraselmis suecica. The effect of two temperatures (20 and 24°C), four salinities (20,25,30 and 37%o) and two food levels (15 000 and 25 000 cells ml-1) on the life history traits of this rotifer were studied in life tables performed with replicated individual cultures. Temper- ature and salinity had a significant negative effect (P < 0.001) on the average lifespan (LS) and on the number of offspring per female (RQ). The effect of food level on LS is unclear, wh…
Effect of temperature on ammonium removal in Scenedesmus sp
2015
The effect of temperature on microalgal ammonium uptake was investigated by carrying out four batch experiments in which a mixed culture of microalgae, composed mainly of Scenedesmus sp., was cultivated under different temperatures within the usual temperature working range in Mediterranean climate (15-34 ºC). Ammonium removal rates increased with temperature up to 26 ºC and stabilized thereafter. Ratkowsky and Cardinal Temperatures models successfully reproduced the experimental data. Optimum (31.3 ºC), minimum (8.8 ºC) and maximum (46.1 ºC) temperatures for ammonium removal by Scenedesmus sp. under the studied conditions were obtained as model parameters. These temperature-related paramet…
Coastal Evolution in a Mediterranean Microtidal Zone: Mid to Late Holocene Natural Dynamics and Human Management of the Castellò Lagoon, NE Spain
2016
We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ~3150 cal BC to the 17th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited …
Antibacterial activity and HPLC analysis of extracts from Mediterranean brown algae
2020
The antibacterial activity of methanolic extracts of eight Mediterranean brown algae belonging to the genera Cystoseira sensu lato, Dictyopteris and Padina was investigated. Extracts from Sargassaceae showed antibacterial activity. Specifically, Carpodesmia crinita and Carpodesmia brachycarpa extracts inhibited the growth of the Gram-positive strain Kocuria rhizophila whereas Cystoseira compressa and Carpodesmia amentacea extracts showed antibacterial activity against the Gram-positive strains, Kocuria rhizophila and Staphylococcus aureus. None of them inhibited the growth of the Gram-negative bacterium Escherichia coli. The extracts of Cystoseira sp. pl. and Treptacantha ballesterosii did …