الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
 |  | from | 193 |  |  |
| | | from | 193 | | |
Abstract
Microalgae biodiesel is a green and renewable energy resource. In this study, ten microalgae isolates were isolated from different samples collected from Egypt. The purified isolates were identified microscopically as: Lyngbya confervoides, Phormidium bohneri, Oscillatoria pseudogeminata, Amorphonostoc sp., Nostoc paludosum, Anabaena sphaerica related to cyanobacteria (blue green algae) and Chlorella vulgaris, Chlorella ellipsoidea, Scenedesmusacutus acutus, Chlamydomonas globosa related to green algae. Lipid production of the ten organisms was examined using the selected solvent system (Hexane-ethanol 1:1). Oscillatoria pseudogeminata and Chlamydomonas globosa were selected for optimization due to their high lipid / dry weight percentage (14% and 13%) respectively. The optimal microalgal growth and lipid productivity were found to be on BG-11 medium with the following incubation conditions: temperature 30oC, incubation period one week , pH 8.5, light intensity 1000 lux, inoculum size 20 ml, 150 ml with static incubation for growth media volume and aeration, zero KGy for gamma radiation, 45 for N/P ratio and finally 0.05 g/l, 1 g/l for nitrogen concentration and 0.00174 g/l, 0.045 for phosphorus concentration for Chlamydomonas globosa and Oscillatoria pseudogeminata respectively. Optimal conditions resulted in 39% and 53% increase in the lipid/Dwt% of BG-11 medium for Chlamydomonas globosa and Oscillatoria pseudogeminata respectively, on the other hand modification of BG-11 using N/P: 45 resulted in 71% and 92% increase in the lipid/Dwt % for Chlamydomonas globosa and Oscillatoria pseudogeminata respectively. Lipid yield by Chlamydomonas globosa and Oscillatoria pseudogeminata using agricultural wastewater was found to be 59% and 55% of that is produced using modified BG-11 respectively. The fatty acid profile obtained by Gas-Chromatography (GC) illustrated that palmitic, stearic, oleic, linoleic and linolenic acids were the most common fatty acids. Although Chlamydomonas globosa and Oscillatoria pseudogeminata are not considered as native isolates for biodiesel production, They can be considered as a promising lipid producing microalgae. Modified BG-11 and agricultural wastewater are considered as a promising source of growth media for production of good biodiesel quality.
Key words: Cyanobacteria, Microalgae, biodiesel, Lipid productivity, Modified BG-11, Agricultural wastewater, Chlamydomonas globosa, Oscillatoria pseudogeminata.
Introduction