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Prof. Sabah Abo-El-maaty Ahmed alsayed :: Theses : |
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| Title | Microbiological and Biochemical Studies on the production of anticandida Secondary metabolites from microbial source |
| Type | MSc |
| Supervisors | Sabah Abo Elmaaty Ahmed; Mervat Gameel Hassan; Ahmed Abd Elghani Hamed |
| Year | 2024 |
| Abstract | Secondary metabolites are compounds neither essential for growth nor key intermediates of the organism’s basic metabolism however playing other roles within the life of microorganisms. They’re typically found as a mix of closely connected molecules with a peculiar and rare chemical structure. Secondary metabolites extracted from living microorganisms such as antibiotics, pigments, toxins, effectors of ecological competition and symbiosis, pheromones, enzyme inhibitors, pesticides, antitumor agents and growth promoters of animals and plants, and can play great role in medicine. The current study has been performed on three candida isolates, which were collected from Kasr Al Ainy University Hospital's Microbiology and Immunology Department. The isolate identified using MALDI-TOF system to confirm the conventional biochemical identification of the most sensitive isolate. So, by morphological, cultural, biochemical characteristics and MALDI-TOF system isolates (SAM11) was confirmed as Penicillium citrinum. Marine microorganisms are a source of new genes, and it is probably going to prompt the revelation of new medications and targets. Secondary metabolites produced by marine microbes have yielded pharmaceutical items. So, thirteen isolates were isolated from three marine samples, thirteen fungal strains (designated as SAM11 to SAM313). Pre-screening biological anticandida activity for the ethyl acetate crude extracts of these isolates against three different candida samples (urine1- urine2- vaginal) was done by using a plate assay method. The isolated fungal acetate extracts were tested for their anticandida activity. Several isolates exhibited anticandida activity against three candida isolate but one isolate (SAM11) from the 13 fungal isolates showed potent anticandida, and were the most effective. While the most of crude isolate have a variable activity against candida isolate. The fungal isolate (SAM11) has high anticandida activity against Candida albicans subjected to molecular identification. The identification was achieved by Morphological, physiological, biochemical and chemo-taxonomical characteristics of streptomycetes isolate H2 and Molecular identification. The sequence data obtained from the strain (SAM11) has been submitted to GeneBank. It has been confirmed that the strain is a member of the genus Penicillium spp. We obtain Penicillium citrinum strain. The strain Penicillium citrinum strain was cultivated on rice medium. After harvesting and scaling up, the obtained crude extract was purified utilizing a variety of chromatography techniques to deliver many fractions with less secondary metabolites and according to the anticandida activity of these metabolites against three candida isolates. Then, we selected a fraction that purified using a series of chromatographic techniques to obtain a pure compound with high activity against three bacterial isolates. The structures of one pure compound with high activity were verified using spectroscopic method (GC-MS). Based on the above spectral data, bioactive compounds was identified In our study, an interesting finding is the inhibition of the Candida albicans by one fraction of Penicillium citrinum crude extract fractionation. The results showed significant inhibition with promising anticandida parameters . The results revealed that the extract exhibited anticandida activity against the tested strains. |
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| University | Benha |
| Country | Egypt |
| Full Paper | - |
| Title | Studies on the production of bioactive Secondary metabolites from streptomycetes against potato pathogenic bacteria |
| Type | MSc |
| Supervisors | Sabah Abo El Maaty Ahmed; Mohammed El-sayed El awady; Mervat Gameel Hassan and Kamel Mohamed Atta |
| Year | 2023 |
| Abstract | In this study, the R. solanacearum Phylotype IIa, sequevar 1 (race 3, biovar 2) strains K3 and K10 were employed. Both of these strains are exceedingly virulent. They were identified in Egypt from symptomatic potato tubers with a distinct characteristic brown rot symptom (brownish browning of vascular bundles with slimy white bacterial ooze), and they had previously been detected by the Bacterial Diseases Research Department in Giza, Egypt. As a result of a pilot survey carried out in this study, which investigated potato plants/tubers with a typical symptom of soft rot and blackleg diseases (wet, slimy, black rot lesion spreading on stems and rotting tuber in different locations in Egypt), twovirulent strains of P. atrosepticum and P. carotovorum, were used in this study. In this study, two strains of R. solanacearum that had previously been identified by the Bacterial Diseases Research Department in Giza, Egypt, were isolated from potato tubers exhibiting a classic brown rot symptom (brownish browning of vascular bundles with slimy whitish bacterial ooze). This symptom was described as "brownish browning of vascular bundles with slimy whitish bacterial ooze." In the course of this study, virulent strains of the bacteria P. atrosepticum and P. carotovorum, were used. All of the plant pathogenic bacterial strains that were used in this research were confirmed by carrying out a PCR experiment using specific primers. The virulence of all R. solanacearum utilised in the research was tested on a seedling of tomato in order to validate its findings. P. carotovorum and P. atrosepticum displayed the typical indications of soft rot and tissue maceration in addition to their other symptoms. |
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| University | Benha |
| Country | Egypt |
| Full Paper | - |
| Title | Bacterial L-Methioninase Enzyme and it's Prospective Application as Anticarcenomic Agent |
| Type | MSc |
| Supervisors | Sabah Abo El Maaty Ahmed, Hamed Mohamed El Shora, Mervat Gameel Hassan |
| Year | 2025 |
| Abstract | L-methioninase was isolated and purified from Staphylococcus sciuri using ammonium sulphate, DEAE-cellulose, Sephadex G-200 and Q-Sepharose with specific activity of 168.7 U mg-1 protein and purification fold of 177.5. The SDS-PAGE exhibited a single band at 48 kDa and this confirms purity of the L-methioninase. Analysis of amino acids of the purified enzyme exhibited variation in the content of the amino acids. The most dominant amino acids were cysteine, aspartic acid, and methionine. The values of Vmax and Km of the purified enzyme were 33.3 U mg-1 protein and 1.7 mM. The optimal pH and the optimal temperature of the enzyme were 8.0 and 40 ºC. The phytohormones activated the L-methioninase with different rates. The four reagents of the active groups namely N-bromosuccinimide (NBS), butanedione (BD), N-ethylmaleimide (NEM) and N-trinitromethane (TNM) inhibited L-methioninase in a concentration-dependent manner confirming the necessity of tryptophanyl, arginyl, sulfhydryl and tyrosyl groups for L-methionine catalysis. L-methioninase exhibited appreciable anticancer effect against HeLa and MCF-7 cell lines. |
| Keywords | |
| University | Benha |
| Country | Egypt |
| Full Paper | download paper |
