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.

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.

Secondary metabolites are substances that have different functions in microorganisms' lives but are not necessary for growth and not important intermediates of the organism's basic metabolism. Secondary metabolites that are taken from living microorganisms especially Streptomyces in our study and have a wide range of applications in medicine especially antibacterial. The current study has been performed on 44 Streptomyces isolates from different marine habitats in Egypt, including Hurgada marine sea, Ras Sedr sediment, Ain Sokhna sediment against thirty-six bacterial isolates were collected from Kafr El-Sheikh General Hospital (KFS) (13 isolates) and Benha University Hospital (BU) (7 isolates) Mabaret El-Asafra hospital (MA) (6 isolates) from middle ear. The purpose of this study was to examine the anti-microbial activity of secondary metabolites derivative from Streptomyces and presented that the extract from Streptomyces sp. strain MKA HG5 which isolated from Hurgada marine sea and identified genetically with accession number OQ924401.1 is the most potent isolate against bacteria that was identified as Brevundimonas sp. strain MKA with accession number OR452707. The Streptomyces extract taken and separated and purified of its bioactive compound by TLC chromatographic. Then the purified bioactive compound identified by GC-Ms. During the course of our work, we isolated a compound with the molecular formula C14H24O3Si2, provide valuable insights into its potential pharmaceutical and medicinal applications. The compound has MW of 296.51 g/mol, with 19 heavy atoms, including 6 aromatic heavy atoms. The fraction of sp3-hybridized carbon atoms (Csp3) is 0.50, indicative of a balanced hybridization state within the molecule. These properties collectively contribute to the compound's structural characteristics, which can influence its behavior in biological systems. C14H24O3Si2 exhibits an optimal bioavailability radar, characterized by balanced lipophilicity, moderate water solubility, high gastrointestinal absorption, blood-brain barrier permeability, and non-substrate status for P-glycoprotein. These features collectively contribute to the compound's potential as a drug candidate with efficient oral bioavailability, laying a solid foundation for further exploration in pharmaceutical development.

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.

Exopolysaccharides produced from marine organisms are one of the natural products that have been used in many fields of biological materials, food, cosmetics and pharmacy. In particular, many of the pharmaceutical properties of marine polysaccharides such as antioxidant, anti-inflammatory, antitumor, anti-obesity, anti-diabetic, anticoagulant, antiviral, immunomodulatory, cardioprotective, anti-hepatoprotective and anti-hepatitis have been revealed. Treatment of inflammation mainly focuses on steroidal and non-steroidal anti-inflammatory drugs. However, side effects, such as high blood pressure, osteoporosis, weakened immunity, hemorrhagic gastritis, upper gastrointestinal ulcers, and hepatotoxicity, make their long-term use controversial and represent an important limitation of the use of these drugs. In light of the continuous search by scientists to find safer anti-inflammatory materials, especially from natural sources, the trend in this study was to produce an exopolysaccharide from some marine bacteria isolated from Red Sea (Ras Sedr and Hurghada) in Egypt due to the difficult and complex conditions in which living organisms live in this sea as it has distinct qualities that are reflected in its biological activities The polysaccharides extracted from marine sources are characterized by their high biological capacity as antioxidants, anti-inflammatory and stimulant for the immune system, which is due to their distinctive chemical structure and stereotype. So, samples were collected from different locations of the Red Sea (Ras Sedr and Hurghada). The method of sequential dilution of the isolation by different isolation environments was used to isolate and purify different bacterial organisms so that they can be used in a pure form. The number of isolates that were isolated reached 12 bacterial isolates (ES1-ES12). The ability of these isolates to produce polysaccharides was tested, and these polysaccharides were evaluated as antioxidants at different times, and the most active promising bacterial isolates having high production of antioxidant (ES12) which subjected to biochemical, morphological, and physiological identification. While, Phylogenetic analysis based on the 16S rRNA gene sequence was done for strain ES12 and compared to reference 16S rRNA gene sequence available in the GenBank database and identified as Pontibacter Sp. strain MSE 2022 with accession number ON479824. Optimization of the environmental and nutritional parameters and the medium contents and their concentration play important roles for increase maximum yields of EPS and its activity. Maximum EPS productivity by Pontibacter Sp. strain MSE 2022 (6.80 g/l) cell dry weight (3.85 g/l) was obtained, after 3 days of incubation (7.1 g/l) and cell dry weight (3.9 g/l) and maximal yield was noticed at pH 7.0 (7.9 g/l) and cell dry weight (4.4 g/l). While, the maximal EPS production (7.0 g/l) at cell dry weight (4.2 g/l) was noticed at 40°C. Thus, maximal yield at 120 RPM was (7.4 g/l) and cell dry weight (4.0 g/l) at 120 RPM. Therefore, the maximal EPS production (7.8 g/l) at cell dry weight (4.1 g/l) was noticed at 750 µl / 50 ml of bacterial inoculum size. Peptone was supported maximal EPSES12 output (8.6 g/l) with cell dry weight (4.5 g/l) as a nitrogen source, and as carbon source sucrose was supported maximal yield (8.0 g/l) at cell dry wight (4.2g/l) at concentration of sucrose 20g/l showed that dry weight was (4.3 g/l and EPSES12 was (8.2 g/l). DPPH free radical scavenging activity technique was used to determine quantitatively the antioxidant activity at various times. Maximum antioxidant activity was 98.39 % at 1 mg/ml after 120 min. H2O2 scavenging activity showed IC50 100 µg/ml at 30 min., Reducing power method (RP) showed that the maximum activity at 1000 µg/ml, and ABTS cation radicals scavenging capability showed high activity at the lowest concentration 100 µg/ml, (52.89 %) increased gradually to 97.98 % by increasing concentration to 1000 µg/ ml. By studying the Chemical analysis of EPSES12 fraction was contained sulfate (14.45%) and has Uronic acid (9.08 %). The monosaccharide composition of this fraction composed of Galacturonic acid, galactose and arabinose with molar ratio 2.3: 5.1: 1.1, respectively. While, molecular weight (Mw) of 5.4×104 g/mol and a number average molecular weight (Mn) 4.9×104 g/mol. The FTIR spectrum fraction exhibited a significant as showed broad characteristic peak at 3282.32 cm-1 region was attributed to the expansion vibration of free O-H in the ingredient sugar residuesmnand the weak CH stretching bands at 2824.03 cm-1. The EPS fraction also appears to have a particular band at 1631.10 cm-1, which is dominated by circle vibrations, while, band at 1333.50 indicate that COO- ionized carboxyl. The absorptions around 1097.14 cm-1 indicated the SO=3 and the strap at 743.04 cm-1 suggested the β-pyranose. Therefore, the infrared spectrometry analysis suggested that it was highly likely that the EPSES12 belonged to a β-type hetero-polysaccharide. Anti-inflammatory activity was determined for EPSES12 by using different ways as Lipoxygenase (LOX) inhibitory gave IC50 15.66 ± 1.12 µg /ml, while control sample (ibuprofen) gave IC50 1.5 ± 1.3 µg /ml. therefore, cyclooxygenase (COX2) inhibitory gave 28.5 ± 1.15 µg /ml, while control (Celecoxib) gave 0.28 ± 1.7 µg /ml. Membrane stabilization inhibitory showed maximum activity inhibition 75.8 ± 0.004µg /ml at concentration 1mg/ml.