Publications by authors named "Safaa M Ali"

4 Publications

  • Page 1 of 1

Effective Elimination of Contaminant Antibiotics Using High-Surface-Area Magnetic-Functionalized Graphene Nanocomposites Developed from Plastic Waste.

Materials (Basel) 2020 Mar 26;13(7). Epub 2020 Mar 26.

Polymer Materials Research Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria 21934, Egypt.

The presence of pharmaceutical residues in aquatic environments represents a risk for the equilibrium of the ecosystem and may seriously affect human safety itself in the long term. To address this issue, we have synthesized functional materials based on highly-reduced graphene oxide (HRGO), sulfonated graphene (SG), and magnetic sulfonated graphene (MSG). The method of synthesis adopted is simple and inexpensive and makes use of plastic bottle waste as the raw material. We have tested the fabricated materials for their adsorption efficiency against two model antibiotics in aqueous solutions, namely Garamycin and Ampicillin. Our tests involved the optimization of different experimental parameters of the adsorption process, such as starting antibiotic concentration, amount of adsorbent, and time. Finally, we characterized the effect of the antibiotic adsorption process on common living organisms, namely DH5α ( DH5α) bacteria. The results obtained demonstrate the efficiency of the method in addressing the issue of the emergence of antibiotic-resistant bacteria, which will help in preventing changes in the ecosystem.
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http://dx.doi.org/10.3390/ma13071517DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177265PMC
March 2020

Stress-Based Production, and Characterization of Glutathione Peroxidase and Glutathione S-Transferase Enzymes From .

Front Bioeng Biotechnol 2020 27;8:78. Epub 2020 Feb 27.

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt.

More attention has been recently directed toward glutathione peroxidase and s-transferase enzymes because of the great importance they hold with respect to their applications in the pharmaceutical field. This work was conducted to optimize the production and characterize glutathione peroxidase and glutathione s-transferase produced by KU720558 using Plackett-Burman and Box-Behnken statistical designs. To assess the impact of the culture conditions on the microbial production of the enzymes, colorimetric methods were used. Following data analysis, the optimum conditions that enhanced the s-transferase yield were the De Man-Rogosa-Sharp (MRS) broth as a basal medium supplemented with 0.1% urea, 0.075% HO, 0.5% 1-butanol, 0.0125% amino acids, and 0.05% SDS at pH 6.0 and anaerobically incubated for 24 h at 40°C. The optimum s-transferase specific activity was 1789.5 U/mg of protein, which was ~12 times the activity of the basal medium. For peroxidase, the best medium composition was 0.17% urea, 0.025% bile salt, 7.5% Na Cl, 0.05% HO, 0.05% SDS, and 2% ethanol added to the MRS broth at pH 6.0 and anaerobically incubated for 24 h at 40°C. Furthermore, the optimum peroxidase specific activity was 612.5 U/mg of protein, indicating that its activity was 22 times higher than the activity recorded in the basal medium. After SDS-PAGE analysis, GST and GPx showed a single protein band of 25 and 18 kDa, respectively. They were able to retain their activities at an optimal temperature of 40°C for an hour and pH range 4-7. The 3D model of both enzymes was constructed showing helical structures, sheet and loops. Protein cavities were also detected to define druggable sites. GST model had two large pockets; 185Å3 and 71 Å3 with druggability score 0.5-0.8. For GPx, the pockets were relatively smaller, 71 Å3 and 32 Å3 with druggability score (0.65-0.66). Therefore, the present study showed that the consortium components as well as the stress-based conditions used could express both enzymes with enhanced productivity, recommending their application based on the obtained results.
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http://dx.doi.org/10.3389/fbioe.2020.00078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057912PMC
February 2020

Production of Cold-Active Lipase by Free and Immobilized Marine HSS: Application in Wastewater Treatment.

Front Microbiol 2018 23;9:2377. Epub 2018 Oct 23.

City of Scientific Research and Technological Applications, Alexandria, Egypt.

Lipases are enzymes that have the potential to hydrolyze triacylglycerol to free fatty acids and glycerol and have various applications. The aim of the present study was to isolate and screen marine bacteria for lipase production, optimize the production, and treat wastewater. A total of 20 marine bacterial isolates were obtained from the Mediterranean Sea and were screened for lipase production. All isolates were found to have lipolytic ability. The differences between the isolates were studied using RAPD-PCR. The most promising lipase producer (isolate 3) that exhibited the highest lipolytic hydrolysis (20 mm) was identified as HSS using 16S rDNA analysis and had the accession number MF581790. Optimization of lipase production was carried out using the Plackett-Burman experimental design with cotton seed oil as the inducer under shaking conditions at 10°C. The most significant factors that affected lipase production were FeSO, KCl, and oil concentrations. By using the optimized culture conditions, the lipase activity increased by 1.8-fold compared with basal conditions. Immobilization by adsorption of cells on sponge and recycling raised lipase activity by 2.8-fold compared with free cells. The repeated reuse of the immobilized HSS maintained reasonable lipase activity. A trial for the economic treatment of oily wastewater was carried out. Removal efficiencies of biological oxygen demand, total suspended solids, and oil and grease were 87.63, 90, and 94.7%, respectively, which is promising for future applications.
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http://dx.doi.org/10.3389/fmicb.2018.02377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205956PMC
October 2018

Optimization of Reduced Glutathione Production by a Isolate Using Plackett-Burman and Box-Behnken Designs.

Front Microbiol 2017 9;8:772. Epub 2017 May 9.

Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology ApplicationsAlexandria, Egypt.

In this work, we aim to optimize the production of reduced glutathione (GSH) synthesized intracellularly by a food-grade microorganism through a statistical approach. Using a colorimetric method, 25 isolates were screened in an attempt to find a GSH-producing strain. It was found that 36% of the tested isolates showed positive result. Isolate (L) was found to produce 152.61 μM glutathione per gram which was the highest amount produced intracellularly. Accordingly, the later isolate was selected for the optimization process using Plackett-Burman and Box-Behnken designs. Temperature, amino acids, and urea were found to be the most significant independent variables. Following data analysis, the composition of the optimized medium was De Man-Sharp-Rogosa broth as a basal medium supplemented with NaCl (5%), HO (0.05%), sodium dodecyl sulfate (0.05%), amino acids (0.0281%), and urea (0.192%). The pH of the medium was adjusted to 8 and incubated for 24 h at 40°C. The GSH amount was increased by 10-fold (851%) using the optimized medium. Hence, our optimization design estimated the biotechnological potential of (L) for the production of GSH in the industry.
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http://dx.doi.org/10.3389/fmicb.2017.00772DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5422468PMC
May 2017