Bacillus spp دراسة الكفاءة للمضادة للميكروبات والتأثير التأزري والنشاط المضادلاكسدة لجسيمات الذهب النانوية المخلقةحيويا بواسطة بكتريا.
| dc.contributor.author | نرجس وحيد ابراهيم | |
| dc.contributor.editor | أ.د. رحمن لعيبي جلاب | |
| dc.date.accessioned | 2025-07-28T20:16:48Z | |
| dc.date.available | 2025-07-28T20:16:48Z | |
| dc.date.issued | 2025-04-22 | |
| dc.description.abstract | The current study included 7 soil samples collected from Al-Fuhud and Al-Hammar marshes south of Thi- Qar Governorate. After isolating Bacillus bacteria through growing them on Selective Bacillus agar medium, bacterial species were selected based on the production of gold nanoparticles after growing them on Brian Heart broth medium. Three species showed their ability to produce gold nanoparticles, where two bacterial species were selected as the most efficient in producing gold nanoparticles. Also, 5 pathogenic bacterial isolates were collected from private laboratories in Thi Qar Governorate. The initial identification of two bacterial species, B. cereus and B. subtilis, producing nanoparticles, was done through morphological and microscopic characteristics. The results of the bacterial species showed that they were Gram-positive rod-shaped bacteria, forming endospores. The identification was also done through biochemical tests, where the bacterial species, B. cereus and B. subtilis, revealed a positive result for each of the tests (Catalase, Citrate Utilization, Methyl red, Voges-Proskauer, and Motility), while they showed a negative result for each of the tests (Oxidase, Gelatin liquefaction and Indole). B. cereus RN2 showed complete hemolysis, negative for Mannitol Utilization and positive for calculus test, while B. subtilis showed partial hemolysis, positive for mannitol degradation and negative for calculus test. The bacterial species under study were B. cereus and B. subtilis and the pathogenic bacterial isolates E. cloacae, E. coli, P. aeurginosa, P. mirabilis, S. haemolyticus, were identified by VITEK 2 device. The gold nanoparticle-producing bacteria B. cereus RNT2 was identified by molecular methods, where the 16S rRNA gene was detected. DNA was extracted from the bacterial species using the extraction kit, using PCR technology. The bacterial species under study possessed this gene, and the size of the gene was 1500 Pb. After determining the gene sequence and comparing it with the National Center for Biotechnology Information gene bank, the data showed that it is a new strain, and B. cereus RNT2 was registered in NCBI. The sensitivity of the pathogenic bacterial isolates under study towards five antibiotics was tested by disk diffusion method. The results showed that the bacterial isolates E. clocae, P. aeruginosa and S. haemolyticus were sensitive to some of the antibiotics used: Azthromycine, Ciprofloxacin and Trimethoprim. While the isolates of E. coli and P. mirabilis showed resistance to all antibiotics under study. The present study dealt with the synthesis of gold nanoparticles from the floating fraction of B. cereus and B. subtilis bacteria. The color change from yellow to dark red is an indication of the production of gold nanoparticles. The ideal conditions for the production of gold nanoparticles were improved by the incubation period, temperature, pH, carbon and nitrogen sources in the single variable method. Gold nanoparticles were produced after growing the bacterial species on Brian Heart broth medium. The results of the present study showed that the best production of gold nanoparticles was at an incubation period of 96-72 hours, a temperature of 370C and a pH of 7. Some carbon sources were used as an alternative to the main source present in the medium at a concentration of 1%. Starch and Arbinose were the best carbon sources, outperforming all other carbon sources. Beef extract was the best nitrogen source, outperforming all other nitrogen sources. All conditions were studied in one experiment and an increase in the intensity of effectiveness against pathogenic isolates was observed after adjusting all conditions. The | |
| dc.identifier.uri | https://dspace.utq.edu.iq/handle/123456789/1029 | |
| dc.title | Bacillus spp دراسة الكفاءة للمضادة للميكروبات والتأثير التأزري والنشاط المضادلاكسدة لجسيمات الذهب النانوية المخلقةحيويا بواسطة بكتريا. | |
| dc.title.alternative | The study of antimicrobial efficiency, synergistic effect and the antioxidant activity of gold nanoparticles are biosynthesis by Bacillus spp. | |
| dc.type | text::thesis::master thesis | |
| oairecerif.author.affiliation | كلية التربية للعلوم الصرفة - قسم علوم الحياة | |
| oairecerif.editor.affiliation | جامعة ذي قار - كلية التربية للعلوم الصرفة - قسم علوم الحياة |