Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Botany and Microbiology

Streptomyces sp. proved as an attractive alternative renewable feedstock for biodiesel. Fifty bacterial species were isolated from different sources. Screening of fatty acids producing bacteria using 2, 3, 5 Triphenyl Tetrazolium Chloride (TTC) and colorimetric methods was performed. About 21 bacterial strains were positive to the TTC test and their total lipids were estimated. All morphological, physiological and biochemical results of isolate number 39 indicated that it belongs to the genus Streptomyces. The comparative analysis of 16S rDNA gene sequence and phylogenetic relationship showed that isolate number 39 lies with strain Streptomyces tunisiensis. Isolate number 39 submitted to the GenBank NCBI with the accession number, MN209228. Streptomyces tunisiensis lipids were extracted and injected into gas chromatography (GC) to show the level of unsaturated fatty acids which is considered a promising way for biodiesel production. The unsaturated palmitoleic acid methyl ester was the most abundant fatty acid followed by Palmitic acid methyl ester. Different optimization parameters were studied to enhance the lipids content. The maximum lipids production by Streptomyces tunisiensis MN209228 was detected using basal liquid medium with initial pH 7.0 and incubation for 5 days at 30{u00B0}C under shaking conditions. The highest lipid accumulation was recorded with basal medium supplemented with glucose as the best carbon source and Na nitrate as the best nitrogen source. Physical properties of obtained biodiesel from Streptomyces tunisiensis MN209228 were determined and found to be as follows: density 0.88 g/cm³, viscosity 4.44 mm₂/s, iodine value 103.45 g I₂/100 g, and cetane number 54.74 min

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