الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Seventy-five actinomycete strains were isolated from different marine localities. The isolates were cultivated on rice media for small scale fermentation. After incubation for 15 days at 28oC, the rice cultures for all isolates were extracted using ethyl acetate to obtain the crude extracts. The obtained small-scale extracts were tested toward several pathogenic microbes including Gram positive bacteria: Staphylococcus aureus, Gram negative bacteria as: Echerichia coli and a fungus as: Aspergillus niger. The isolate that exhibited the potent antimicrobial activity was selected, identified by morphological examination and genetically by extraction of the genomic DNA, sequencing and analysis. Additionally, the up-scale production for the antimicrobial agent by the most potent isolate was carried out by inoculation of the isolate on rice medium to obtain up scale crude extracts. chromatographic purification, and structural elucidation led to the isolation of one compound namely cis-9-Octadecenoic. The antimicrobial activity of the obtained compound showed that it has a pronounced antibacterial activity toward Echerichia coli, Klebsiella pneumonia and Salmonella typhi. While it showed a moderate antifungal activity against Aspergillus niger and Candida albicans. The biofilm inhibitory activity was detected toward the biofilm forming bacteria including (Staphylococcus aureus, Bacillus subtilis, Pneumonia aeruginosa and Echerichia coli). On the other hand, the obtained compound showed a strong anticancer activity against Hep G2 while it displayed a moderate anticancer activity against breast cancer. Furthermore, the evaluation of inhibition activity against Topisomerase Ⅱ was also measured. Finally, the ADME (Absorbtion, Distribution, Metabolism and Excretion) related physiochemical properties and prediction of toxicity of the obtained compound was evaluated using online portal swiss ADME and protox Ⅱ respectively.
Key words: Actinomycetes, Antimicrobial activity, Toxicity and Biofilm.