الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
The present study provides a detailed description of phytochemical and biotechnological aspects of the endophytic bacteria from Calotropis procera, through the following objectives: Isolation, purification and characterization of endophytic bacteria inhabiting Calotropis procera. Investigating the potentiality of the isolated endophytic bacteria in production of lipase, amylase, cellulase, gelatinase, caseinase, and catalase. Evaluation of chemical constituent’s profile and biological activity of the endophytic host of Calotropis procera. In the present study, three bacterial isolates of endophytes were isolated and purified from Calotropis leaves collected from their different natural habitats in the northern part of the Eastern Desert of Egypt (Wadi Hagul). Biochemical characterization of these isolates showed that, they can produce several enzymes as (caseinase, cellulase, lipase, protease, amylase, catalase and gelatinase). For morphologically characters, it was noticed that all bacterial isolates (Cal, Cal2 and Cal3) were Gram-negative, short rod bacilli and the color was off-white for Cal1, pale yellow for Cal2 and white for Cal3. For CMC test, the three isolates Cal1, Cal2 and Cal3 had no clear zone on modified CMC agar medium. Congo red stain used to give a red color to cellulose in the media. For gelatin hydrolysis, the three isolates Cal1, Cal2 and Cal3 had no clear zone indicating gelatin hydrolysis on the modified gelatin agar medium without gelatin hydrolysis. The three isolates Cal1, Cal2 and Cal3 had no clear zone on modified Casein agar medium. In catalase test, the effervescence reaction resulted from dropping of Hydrogen Peroxide on a DROP of liquid culture placed on a slide. Effervescence happened in the case of Cal1 and Cal2, but no bubbles with Cal3 isolate. The different extracts of C. procera form aerial parts showed a significant antimicrobial inhibitory effect on the growth of the tested Gram-positive and Gram-negative bacteria. In this study, methanol extract of C. procera expressed wide antimicrobial spectrum (100%) against both Gram-positive bacteria and Gram-negative bacteria. Highest antibacterial activity was shown by methanol extract against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. On the other hand, Escherichia coli was the most sensitive bacteria in case of methanol extract, whereas Staphylococcus aureus and Klebsiella pneumoniae were the most susceptible in case of methanol and petroleum ether extracts, while the most resistant bacteria were Listeria monocytogenes and Streptococcus epidermis. The powder and crude extract of C. procera aerial parts subjected to phytochemical screening and the results recorded. In case of methanol solvent, the extract showed the presence of all tested chemical constituents except coumarins. While, traces or absence of phytoconstituents were observed in petroleum ether and water solvents. Moreover, the results showed that, the aerial parts contained mainly alkaloids and phenolics compound. While tannins, flavonoids and saponins recorded moderate values. The crude extract from the aerial parts of C. procera expressed adequate radical scavenging activity of the DPPH in a concentration-dependent manner.