Macroalgae are a valuable source of highly bioactive primary and secondary metabolites that may have useful bioapplications. To investigate the nutritional and nonnutritional contents of underexploited edible seaweeds, proximate composition, including protein, fat, ash, vitamins A, C, and E, and niacin, as well as important phytochemicals, including polyphenols, tannins, flavonoids, alkaloids, sterols, saponins, and coumarins, were screened from algal species using spectrophotometric methods. Ash content ranged from 3.1525.23 for green seaweeds, 529.78 for brown algae, and 731.15 for red algae. Crude protein content ranged between 5 and 9.8 in Chlorophyta, 5 and 7.4 in Rhodophyta, and between 4.6 and 6.2 in Phaeophyceae. Crude carbohydrate contents ranged from 20 to 42 for the collected seaweeds, where green algae had the highest content (22.542), followed by brown algae (2129.5) and red algae (2029). Lipid content was found to be low in all the studied taxa at approximately 16, except for Caulerpa prolifera (Chlorophyta), which had a noticeable higher lipid content at 12.41. These results indicated that Phaeophyceae were enriched with a high phytochemical content, followed by that of Chlorophyta and Rhodophyta. The studied algal species contained a high amount of carbohydrate and protein, indicating that they could be considered as a healthy food source.

A green, eco-friendly approach to biosynthesizing silver nanoparticles has been reported for marine macroalga (Cystoseira myrica) extract as a reducing agent. Different pH and temperature impact the green synthesis of silver nanoparticles suggesting that the synthesis depends greatly on pH and temperature. The structure and characters of synthesized nanoparticles were confirmed using HR-TEM, DLS, XRD, and FTIR. Cytotoxicity was indicated using provided cell lines of breast carcinoma cells (MCF-7) and human hepatocellular carcinoma cells (HepG2). Shape of silver nanoparticles at pH 9 and 75°C for 30min was found to be suitable for the biosynthesis process and the AgNPs exhibited a characteristic absorption peak at 434nm. High Resolution Electron Microscope Transmission reported polydisperse and spherical shapes ranging from 8 to 15nm. High attractive and repulsive forces between each nanoparticle were recorded with an average zeta-potential value of approximately 29.3mV. The X-ray diffraction study revealed the crystalline structure of silver nanoparticles. FTIR has shown the bioreduction of silver ions to silver nanoparticles through biomolecules found in algal extract. Silver nanoparticles have been found to have anticancer activity. The cytotoxicity assay was studied against MCF-7 and HepG2 at various concentrations (100, 50, 25, 12.5, 6.25, 3.125, 1.56, 0.78, 0.39, 0.2, and 0.1μg/mL). By increasing the concentration of AgNPs from 0.1 to 100μg/mL, the maximum percentage of viability against MCF-7 and HepG2 cell line decreased from 94.55±7.55 to 19.879±0.503 and from 78.56±11.36 to 25.81±2.66 after time exposure, respectively.

Ismailia Canal is one of the main artificial branches of River Nile in Egypt, it is the most important one as a source of water supply for several governorates in the east of Nile Delta. In this study, phytoplankton composition and some physico- chemical parameters have been studied in twelve points along the main route of Ismailia canal between Cairo and Ismailia governorates to follow up changes in the water quality of the canal. Samples have been collected monthly in the period from February 2015 to January 2016. A total of 143 phytoplankton taxa related to 55 genera were identified related to six algal divisions namely; Chlorophyta (69 taxa), Bacillariophyta (51 taxa), Cyanophyta (18 taxa), Euglenophyta and Dinophyta (each represented by 2 taxa) and finally Xanthophyta represented by one taxon. Quantitatively, Bacillariophyta was the most dominant division with algal density represented more than 86% of average total phytoplankton count. The highest phytoplankton density was recorded in winter, while the minimum was recorded in summer. Water of Ismailia Canal was found to be slightly alkaline. Concentrations of nitrogen, phosphorus and silicate were found to be markedly affected by the water level of the canal along the year as well as the pollution runoff from ambient pollution sources. Phytoplankton composition of the canal also seems to be affected by pollutants especially at the far eastern part of the canal that located in Ismailia city. On the long run increasing of industrial and agricultural run-off may affect the water quality of the canal, so continuous studies must be carried out to follow up the changes in water of the canal.

Biosorption has emerged as a cost-effective and efficient alternative technology for removal of heavy metals which produce adverse health effects on humans and living organisms. In the present study the biosorption and desorption of cadmium, lead and zinc by Chlamydomonas variabilis, Anabaena constricta andNitzschia linearis were evaluated. Algal species were isolated and cultivated on a large scale to get an intensive biomass sufficient for metal binding experiments. The experimental adsorption data were fitted to the Langmuir and Freundlich adsorption model. Characterization of the metal-loaded biosorbent by FTIR spectrum, TEM and EDX analysis confirmed that the metal ions can bind to anionic groups due to electrostatic attraction and sorption capacity is strongly influenced from the type and number of functional groups of the biosorbent. The maximum efficiencies of Cd, Pb and Zn removal using C. variabilis were 97.9%, 96.1% and 96.1% for oven dried biomass and 96.3%, 94.2% and 94.1% for activated biomass. For dried and activated biomass prepared of A. constricta the maximum percentage of removal of heavy metals were95.1%, 93.7%, and 93.1% and94.3%, 96.1% and 94.1%. The maximum removals by N. linearis were 95.5%, 96.6%, 94.8% for oven dried biomass and 93%, 94.5% and 93.8% for activated one respectively. There are no clear variations in biosorption of cadmium, lead and zinc by sun dried, oven dried and activated biomass of C. variabilis, A. constricta and N. linearis. It is better to use sun dried algae as low cost biosorbent for metals removal.

Four different solvents were used to study their efficiency on pigments extraction from three different algal species of Chlorella vulgaris, Spirulina platensis and Nannochloropsis oculata. Dimethylsulfoxide, acetone, ethanol and methanol were used in the extraction process. The experiment was performed in both of fresh and oven dried algal samples. Chlorophylls a, b, total chlorophyll and total carotene concentrations were determined spectrophotometrically and by HPLC technique. The spectrophotometric method revealed that, dimethylsulfoxide surpasses all other used solvents in all species and all pigments in fresh samples except for chlorophyll a of N. oculata, whereas acetone was more effective than the others in fresh and dry sample. For the dried sample of C. vulgaris, methanol gave the maximum extractability with chlorophyll a while chlorophyll b and total chlorophyll were found be maximum in dimethylsulfoxide solvent. In Spirulina, methanol represented the maximum chlorophyll a and total chlorophyll for the dried samples. Total carotene was found to be higher in ethanol solvent with both C. vulgaris and N. oculata but dimethylsulfoxide surpasses the other solvents with S. platensis. HPLC results emphasized that, acetone surpasses all other used solvent in fresh samples and methanol was ideal solvent in dry samples of C. vulgaris. Dimethylsulfoxide represented the maximum chlorophyll a and total carotene with Spirulina in both samples. Methanol was the best solvent for extraction of all pigments with N. oculata except with β-carotene of dry sample, ethanol was the best solvent.