الفهرس 
Table of ContentsOnly 14 pages are availabe for public view
 |  | from | 196 |  |  |
| | | from | 196 | | |
Abstract
The aim of this research was to examine the chemical composition of S. glaucus from various environments in Egypt, as well as the antioxidant, and antimicrobial activities; and to isolate endophytic bacteria from parts of S. glaucus collected from 2 diverse habitats from Egypt and identify their capability for their biochemical activities. Total 10 endophytic bacteria were obtained from the isolation; the highest diversity of bacterial endophytes was observed in roots and leaves of desert samples. The isolates were recognized based on 16S rRNA sequence genes. These isolates all indicate the ability to produce enzymes such as amylase, cellulase, lipase, catalase, and protease in their biochemical descriptions; analyses also gave a significant indication of their potential to produce plant growth hormones that can increase growth and protection; as their ability to dissolve Phosphate, and through the tests showed the strength of these isolates on the production of indole and gibberellins, while no strain were able to produce hydrogen sulfide (H2S). The general assessment of the analytical results for different parts of S. glaucus showed that the capitula and leaves in both inland and coastal samples were rich in bioactive constituents than the other parts as following (capitula > leaf > root > stem). The IC50 values ranged from 25.94 to 41.20 mg/ml in coastal sample, where the IC50 values ranged from 28.02 to 42.83 mg/ml in desert sample, compared to ascorbic acid (IC50 = 13.30 mg/ml). The antimicrobial potential of MeOH extracts of S. glaucus parts collected from different habitats exhibited different inhibitory spectrum behavior with varying degrees of inhibition against six Gram-positive bacteria and four Gram-negative bacteria. The results of the antibacterial test were compared with 3 standard antibiotics.