الفهرس 
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Abstract
In recent days, diverse applications of nanoparticles (NPs) involves crop protection and production, cosmetics, drug delivery, photonic crystals, analysis, food, coatings, paints, catalysis and material science. The application of nanomaterials in algal biotechnology is still in its nascent phase and little is known about the experimental approaches and control of characteristics of the NPs to facilitate the development of NPs application in algal cultures.
In this study, metal nanoparticles, especially those containing heavy metal or trace metal ions, such as ZnO are found to be related to reactive oxygen species (ROS) generation inducing oxidative stress on micro algae (Botryococcus braunii and Scendesmus dimorphus) which improve algal biomass, lipid and oil production.
Therefore, ZnO NPs are applied in algal biodiesel production. Also, different concentrations of silver nanoparticles (AgNP) which are biologically synthesized by different algal extracts from different algal species (Spirulina platensis (Cyanophyta), Chlorella vulgaris, Ulva lactuca (Chlorophyta) and Sargassum denticulatum (Phaeophyta) have to be added to the algal biomass as atrial to improve oil extraction. characterizations for ZnO and Ag NPs synthesized by the four algal extracts were performed by UV-Visible Spectroscopy (UV-Vis), X-ray Diffraction (XRD) and particle morphology and size of silver nanoparticles were observed by TEM.
It was found spherical shaped nanoparticles sizes with average diameter of approximately 32.45 nm for ZnO NPs and 20,78.8, 31 and 50 nm from the four algal extracts (Ulva lactuca, Sargassum denticulatum, Chlorella vulgaris and Spirulina platensis) respectively. The phytochemical analysis for the algal biomass (Botryococcus braunii and Scendesmus dimorphus) was done. The results of the phytochemical analysis showed that chlorophyll concentration ranged between 0.188-1.578 mg/l and 0.21-2 mg/l, carotenoids ranged between 0.02-0.085 mg/l and 0.056-0.092 mg/l, total sugars ranged between 23.155-26.417 % and 24.028-27.452 %, soluble sugars ranged between 13.6-16.2 % and 14.8-18.4 %, total protein content ranged between 9.55-14.3% and 7.79-12.67 %, soluble proteins ranged between 3.96-7.4% and 3.3-6.06%, proline content ranged between 0.22-0.55 % and 0.32-0.68 %, total lipids ranged between 27.6-38.5% and 19.6-31.3 % for Botryococcus braunii and Scendesmus dimorphus respevtively.
Also, the phytochemical analysis for the four algal extracts was done. Results of oil concentration for Scenedesmus dimorphus ranged between 9.9-18.6% at 8 ppm Ag-NPs in group IV and 2 ppm Ag-NPs in group II from Sargassum denticulatum and Ulva lactuca respectively. Oil concentration for Botryococcus Braunii ranged between 15.1- 24.5% at 8 ppm Ag-NPs in group IV and 2 ppm Ag-NPs in group II from Sargassum denticulatum and Ulva lactuca respectively.
Furthermore, physico–chemical properties of the biodiesel obtained from Botryococcus braunii and Scendesmus dimorphus such as Flash point (D93), Kinematic viscosity at 40 ºC (D445), Cetane number (D631), Cloud point (D5773), Pour point (D97), Heating value (D4891), Density (D4052), Iodine number, Sulphated ash and Carbon residue were done.
In this study, it has been demonstrated that adding zinc oxide nanoparticles (ZnO NPs) with low doses in the culture media of Botryococcus braunii and Scendesmus dimorphus increased the growth rate, biomass, lipids and oil production. The algal extracts for Ulva lactuca, Sargassum denticulatum, Spirulina platensis and Chlorella vulgaris as a reducing agent can effectively produce spherical shaped silver nanoparticles by the green chemistry approach which improved the oil extraction and biodiesel production.