الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The demand for ethanol has been on the increase due to its various uses such as, chemical feedstock and more importantly as an alternative source of liquid fuel for automobiles. One of the ways of producing ethanol is through fermentation of crops which are rich in sugar or starch such as sugarcane, sugar beet, and corn (food substrates). Accurate cultivation of algae is a good solution to solve all the environmental problems such as global warming and the increase of the ozone hole and climate change because of these algae consume a large amount of carbon dioxide during photosynthesis to produce oxygen and a large amount of carbohydrate which is used for the production of bio-ethanol by fermentation process. In view of the above the present study followed different approaches which aimed at meeting the following objectives. Isolation of different micro and macro algae that can be used as a biomass for bioethanol production. Finding best conditions for degrading complex component of algal biomass. Isolation of different microorganisms that can degrade algal complex components to simple sugars that can be used in bioethanol production by fermentation process. Bioethanol production by different microorganisms grown on algal sugar. This work includes: Studying of effect of different media (Kuhl and BG11) on Chlorella vulgaris growth measured by O.D and dry weight assay. Chlorella vulgaris was isolated, purified and identified by algal base to be used in our study. Two inorganic defined media (Kuhl and BG11) varying in their composition was used, measuring the optical density (O.D) and dry weight clearly indicated that the best growth of Chlorella vulgaris was obtained in Kuhl medium. Different algal samples were collected and identified Enteromorpha compressa was collected in 13 December 2011 .Ulva fasciata , Gelidium crinale and Colpomenia sinuosa were collected in 7 April 2012 from the shallow water beside the shore of Mediterranean sea at Abo Qir coast . Effect of different treatments (different acids and base concentrations combined with autoclaving for different rounds) on ratio of reduced sugar obtained from hydrolysis of different algae were studied. Dilute acid and base hydrolysis of macro-algae and microalga were performed at different concentrations of 1, 3, 5, and 7% at autoclave for one, two and three rounds. The maximum yield of sugar obtained from Chlorella vulgaris was 405 ±5.75mg sugar/gm dry alga when alga treatment by 5% hydrochloric acid for three rounds. While in sulfuric acid treatment best condition was 298.6 ±4.02mg sugar/gm dry alga by 7% sulfuric acid for one autoclave round, obtained from Enteromorpha compressa . 5% sulfuric acid with three autoclave rounds was the best conditions for Colpomenia sinuosa treatment as it releases 197 ±21.37mg sugar from each gm of dry alga. 3% sulfuric acid with one autoclave round was the best treatment conditions that release 700 ±26.10mg sugar for each gm of dry alga of Ulva fasciata. Gelidium crinale was treated with the same different methods applied on the all previous algae and the best conditions of treatment was 7% ammonium oxalate with three autoclave rounds that gave 676 ±3.8mg sugar for each gm dry alga. Isolation of different microorganisms grown on algal sugar was done in this study and two bacterial isolates gave the maximum activity were purified and screened for different enzymes production and identified biochemically and genetically. The two isolated strains identified as Bacillus subtilis and Bacillus cereus. These strains gave amylase and cellulase production activities and studied for bioethanol production. Hydrolysis of algae with bacterial growth and partially purified amylase enzyme has been studied. For Ulva fashiata treatment with Bacillus subtilis SH04 gave the maximum yield of sugar 640.96 ±9.65mg sugar for each gm dry alga while in Enteromorpha compressa biological hydrolysis by growth of Bacillus cereus SH06 gave the maximum yield of sugar 258.244 ±2.45mg sugar for each gm dry alga. HPLC analysis of free sugars obtained from chemical hydrolysis process was performed for each alga. Fructose, lactose, galactose, inulin, mannitol, glucose, and glucoronic acid were determined by HPLC from algae hydrolysate. The results showed that the presence of mannitol, lactose, inuline, glucose, galactose and glucoronic acid in Ulva fasciata. In addition mannitol, lactose, glucose, galactose and glucoronic acid were presented in the hydrolysate of Enteromorpha compressa. These results indicate that algae pretreatment by dilute acid improved the degradation of cellulose during the acid hydrolysis. Glucose, glucoronic acid, galactose, mannitol, fructose and lactose were founded on analysis results of Colpomenia sinuosa. In Chlorella vulgaris mannitol, fructose, glucornic acid, lactose; inulin, glucose and galactose were founded. Gelidium crinale gave mannitol, lactose, inulin, galactose and lucoronic acid by HPLC analysis Bioethanol production from reduced sugars of algae was studied at different sugar concentrations. For bioethanol production by Saccharomyces cerevisiae SH02 .Three trials were performed using common baker’s yeast, varying sugar concentrations applied at the best conditions reported before by different researches. The best ethanol production was at 5% sugar concentration (acid hydrolysis) 78.3% and with increasing sugar ratio ethanol production decreases at 30 0C and pH were 5.5. Bioethanol production was also performed using Pseudomonas sp SH03 with studying the best sugar concentration for bioethanol production the maximum ethanol yield was 43% from fermentation of 5% sugar (acid hydrolysis). The best conditions obtained from this study were applied on bioethanol production from algal biomass by the identified strains isolated in this study (Bacillus subtilis, Bacillus cereus). Maximum ethanol yield production from Bacillus subtilis SH04 was 27.4% from 5% sugar from acid hydrolysis and 10.5% ethanol yield from 15% sugar concentration from enzymatic hydrolysis. While in fermentation of 5% sugar from acid hydrolysis by Bacillus cereus SH06 ethanol yield was 51.6% but in fermentation of 15% sugar from enzymatic hydrolysis ethanol yield was 18.6%. In conclusion, these results approve that the microalgae and macro algae can grow almost anywhere, requiring sun light and simple nutrients, although the growth rates can be accelerated by using specific medium with specific simple nutrients. The macro and microalgae biomass having very good potential for bioethanol production because algae are very rich in carbohydrates.