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result(s) for
"Hegazy, Ghada E."
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Maximization of red pigment production from Streptomyces sp. LS1 structure elucidation and application as antimicrobial/antifouling against human pathogens and marine microbes
by
Hegazy, Ghada E.
,
Abdelgalil, Soad A.
,
Abdel-Meguid, Dina I.
in
Actinomycetes
,
Algae
,
Antibacterial activity
2022
Natural dyes are present in living organisms such as animals and plants and microorganisms such as fungi, bacteria, algae, and yeast. Pigments are fast and easy growth by using cheap components and do not effect by environmental conditions because they required some physical factors like heat, light, and pH and also they have many biotechnological applications such as medical and industrial needs. The natural pigments can act as antimicrobial agents and are used in drug manufacturing. Also, it can be used in the food industry as natural colorants instead of the synthetic colorants due to their safety on human health and low toxicity when emitted into the environment. A pigmented actinomycetes LS1 strain isolated from El Mahmoudia canal (sediment soil) located in Egypt was microscopically examined and identified as Streptomyces sp. by molecular approach. Extraction, purification, and characterization of produced red pigment metabolite like carotenoids related were established based on spectroscopic studies and comparing the data from the literature. Factors (nutritional and physical) influencing red pigmentation by this isolate were investigated through One Variable At Time (OVAT), and then, the optimal levels of the significant key variables were recorded. Also, the productivity yield reached 30 mg of dried purified pigment/gram dry weight. The biological activity of the red product was tested against Gram-positive and Gram-negative marine bacterial pathogens; the recorded antimicrobial activity is more prominent against (P. aeruginosa ATCC 9027, K. pneumoniae ATCC 13883, S. aureus ATCC 6538, B. subtilis ATCC 6633 and E. coli ATCC 10418) at nearly 0.07 mg mL.sup.-1 concentration. Also, the tested red pigment showed a positive antifouling activity (AF) against marine microbes; the activity increased by increasing the pigment concentrations from 1 to 3 mg mL.sup.-1. The present work focused on the optimization of culture conditions for the production of red pigment by Streptomyces sp. LS1; then, the antibacterial activity and antifouling activity of the produced pigments were tested.
Journal Article
Polyurethane-based foam composites: synthesis, structural characteristics, and radiation shielding properties
2025
This study investigates the potential of pure polyurethane (PU) foam as a lightweight, cost-effective shielding material against ionizing radiation, emphasizing its adaptability for incorporating high-performance fillers. PU foam was doped with various materials, including NiO, ZnO, Cr
2
O
3
, MnO
2
, BaO(Fe
2
O
3
)
6
, and sludge (at 44.5 wt.% loading), to enhance its shielding properties. The synthesized composites were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and X-ray Fluorescence (XRF). Radiation shielding performance was evaluated through Monte Carlo simulations (MCNP) and Phy-X software for γ-rays (0.015–15 MeV) and fast neutron attenuation (up to 11 MeV). Results showed that incorporating high-density, high-atomic-number fillers significantly improved γ-ray attenuation, with BaO(Fe
2
O
3
)
6
demonstrating the highest linear attenuation coefficient. Conversely, pure PU foam effectively attenuated fast neutrons due to its high concentration of light elements. The findings highlight PU-based composites as promising materials for γ-ray and neutron shielding, particularly in X-ray protection and radiological safety applications.
Journal Article
Purification and fractionation of phycobiliproteins from Arthrospira platensis and Corallina officinalis with evaluating their biological activities
2023
Phycobiliproteins (PBPs) are a class of water-soluble pigments with a variety of biological functions that are present in red macroalgae and cyanobacterial species. The crude forms of phycocyanin (C-PC) from the blue green alga
Arthrospira platensis
and allophycocyanin (APC) from the red macroalga
Corallina officinalis
were extracted and purified by ammonium sulphate precipitation, anion exchange chromatography, and size exclusion chromatography methods, respectively. The obtained C-PC and APC from
A. platensis
and
C. officinalis
were 0.31 mg/mL and 0.08 mg/mL, respectively, with molecular masses of “17.0 KDa and 19.0 KDa” and “15.0 KDa and 17.0 KDa” corresponding to α and β subunits, respectively. FT-IR was used to characterize the purified APC and C-PC in order to look into their structures. Highly purified extracts (A620/A280 > 4.0) were obtained from subtractions’ PC3 and PC4 that were tested for their biological activities. APC and C-PC crude extracts plus their fractions exhibited potent anti-oxidant in different ratios by using three techniques. PC1 showed high anti-inflammatory (75.99 and 74.55%) and anti-arthritic (78.89 and 76.92%) activities for
C. officinalis
and
A. platensis
, respectively compared with standard drugs (72.02 and 71.5%). The methanolic and water extracts of both species showed greater antibacterial efficacy against Gram +ve than Gram −ve marine bacteria. Our study shed light on the potential medical uses of C-PC and APC extracted from the tested species as natural substances in a variety of foods and drugs. Further investigations are required to explore the diverse chemical natures of distinct PBPs from different cyanobacteria and red algae because their amino acid sequences vary among different algal species.
Journal Article
Isotherm and kinetic studies of cadmium biosorption and its adsorption behaviour in multi-metals solution using dead and immobilized archaeal cells
2023
It is crucial to identify more biological adsorbents that can efficiently uptake metals from wastewater. Dry haloalkaliphilic archaea
Natronolimnobius innermongolicus
was evaluated for Cd ions biosorption. The optimal operating conditions (pH, biomass dose, initial metal concentration, contact time, and isotherms models) were tested. Biosorption process is influenced by the metal's solution pH with maximum removal of 83.36% being achieved at pH 8. Cadmium ions uptake reaches equilibrium in about 5 min of biosorption process. The Langmuir model was determined to better fit the Cd(II) biosorption by dry archaea. The maximal uptake capacity (q
max
) of Cd(II) was 128.21 mg/g. The effect of multi-component system on biosorption behaviour of Pb, Ni, Cu, Fe, and Cd ions by immobilized dried archaeal cells, dried archaeal cells, and dried bryozoa was studied using Plackett–Burman experimental design. The investigated biosorbents were effective at removing metals from contaminated systems, particularly for Fe, Pb, and Cd ions. Moreover, the interaction behaviour of these metals was antagonistic, synergistic, or non-interactive in multi-metals system. SEM, EDX, and FTIR spectra revealed changes in surface morphology of the biomass through the biosorption process. Finally, continuous adsorption experiment was done to examine the ability of immobilized biomass to adsorb metals from wastewater.
Journal Article
Exploring the antimicrobial, antiviral, antioxidant, and antitumor potentials of marine Streptomyces tunisiensis W4MT573222 pigment isolated from Abu-Qir sediments, Egypt
by
Hegazy, Ghada E.
,
Olama, Zakia A.
,
Ramadan, Heba S.
in
Actinomycetes
,
Anti-Bacterial Agents - chemistry
,
Anti-infective agents
2023
Due to the therapeutic importance of microbial pigments, these pigments are receiving the attention of researchers. In this present study 60 isolates were isolated from sediments of Abu-Qir coast of the Mediterranean sea, Alexandria, Egypt, out of which 12 were considered as pigmented actinomycetes.
Streptomyces
sp
.
W4 was characterized by small round green pigmented colonies when grown on starch-casein agar medium. The green pigment was extracted using a mixture of acetone-methanol (7:3 v/v). The antimicrobial, antioxidant, antiviral, and anticancer activities of the green pigment produced by
Streptomyces
sp.W4 were investigated. The pigment was characterized using FTIR, Raman spectroscopy, EDX and GC–MS. The results revealed that the pigment has antibacterial and antifungal activity and also showed inhibition of HAV 78% but its antiviral activity against the Adenovirus was weak. The results proved the safety of the pigment toward normal cells and anticancer activity against three different cancer cell lines HepG-2 (liver cancer cell line), A549 (lung cancer cell line), and PAN1 (pancreas cancer cell line). The pigment was combined with 9 antibiotics and then tested against the Gram-negative bacterium
Enterococcus faecalis
using disc diffusion bioassay. LEV showed an antagonistic effect, while CXM and CIP showed a synergistic effect.
Journal Article
Enhanced voltage generation in microbial fuel cells (MFCs) using bacterial isolates from seawater and industrial wastewater
by
Hegazy, Ghada E.
,
Abdel-Fattah, Yasser R.
,
Taha, Tarek H.
in
Alternative energy
,
Alternative energy sources
,
Applied Microbiology
2025
Background
This study investigates the potential of microbial fuel cells (MFCs) for bioelectricity generation from seawater and wastewater sources. It focuses on the isolation, identification, and statistical optimization of electrogenic bacteria from diverse environmental samples, aiming to enhance sustainable production of bioenergy.
Results
Four bacterial isolates were obtained from Max surface water, oil factory wastewater, Abu-Qir bottom sediment, and fish factory wastewater.
16 S rRNA
gene sequencing identified these isolates as
Stenotrophomonas
sp. strain S2 (El-Max),
Bacillus paralicheniformis
strain O3 (Oil factory),
Bacillus safensis
strain QB (Abu-Qir), and
Serratia
sp.strain GH3 (Fish factory). Initial screening of microbial consortia showed promising bioelectricity generation, with voltage outputs ranging from 0.175 V to 0.542 V crosswise isolates. Statistical method using Plackett–Burman Design (PBD) screened the key factors influencing voltage production, including pH, time, oxygen, inoculum size, mediator, and resistance. Each isolate exhibited a distinct pattern of factor significance, yet the models for the four strains demonstrated excellent predictive power with
R²
values near 0.98 or higher.
Conclusion
These results underscore the strong potential of specific electrogenic bacterial strains, isolated from diverse wastewater sources, to enhance bioelectricity production in Microbial Fuel Cells (MFCs). The identification of critical operational parameters provides valuable insights for optimizing MFC performance. Together, these findings demonstrate the viability of MFCs as an effective dual-purpose technology for wastewater treatment and renewable energy production.
Journal Article
Isolation and characterization of Candida tropicalis B: a promising yeast strain for biodegradation of petroleum oil in marine environments
by
Hegazy, Ghada E.
,
El-Helow, Ehab R.
,
Yusef, Hoda Y.
in
Alternative energy sources
,
Applied Microbiology
,
Aromatic hydrocarbons
2024
The increasing interest in environmental protection laws has compelled companies to regulate the disposal of waste organic materials. Despite efforts to explore alternative energy sources, the world remains heavily dependent on crude petroleum oil and its derivatives. The expansion of the petroleum industry has significant implications for human and environmental well-being. Bioremediation, employing living microorganisms, presents a promising approach to mitigate the harmful effects of organic hydrocarbons derived from petroleum. This study aimed to isolate and purify local yeast strains from oil-contaminated marine water samples capable of aerobically degrading crude petroleum oils and utilizing them as sole carbon and energy sources. One yeast strain (isolate B) identified as
Candida tropicalis
demonstrated high potential for biodegrading petroleum oil in seawater. Physiological characterization revealed the strain’s ability to thrive across a wide pH range (4–11) with optimal growth at pH 4, as well as tolerate salt concentrations ranging from 1 to 12%. The presence of glucose and yeast extract in the growth medium significantly enhanced the strain's biomass formation and biodegradation capacity. Scanning electron microscopy indicated that the yeast cell diameter varied based on the medium composition, further emphasizing the importance of organic nitrogenous sources for initial growth. Furthermore, the yeast strain exhibited remarkable capabilities in degrading various aliphatic and aromatic hydrocarbons, with a notable preference for naphthalene and phenol at 500 and 1000 mg/l, naphthalene removal reached 97.4% and 98.6%, and phenol removal reached 79.48% and 52.79%, respectively. Optimization experiments using multi-factorial sequential designs highlighted the influential role of oil concentration on the bioremediation efficiency of
Candida tropicalis
strain B. Moreover, immobilized yeast cells on thin wood chips demonstrated enhanced crude oil degradation compared to thick wood chips, likely due to increased surface area for cell attachment. These findings contribute to our understanding of the potential of
Candida tropicalis
for petroleum oil bioremediation in marine environments, paving the way for sustainable approaches to address oil pollution.
Journal Article
Microbial dynamics, chemical profile, and bioactive potential of diverse Egyptian marine environments from archaeological wood to soda lake
by
Hegazy, Ghada E.
,
Oraby, Hussein
,
Othman, Sarah Samir
in
631/326
,
631/326/26
,
631/326/26/2523
2024
Halophilic archaea are a unique group of microorganisms that thrive in high–salt environments, exhibiting remarkable adaptations to survive extreme conditions. Archaeological wood and El–Hamra Lake serve as a substrate for a diverse range of microorganisms, including archaea, although the exact role of archaea in archaeological wood biodeterioration remains unclear. The morphological and chemical characterizations of archaeological wood were evaluated using FTIR, SEM, and EDX. The degradation of polysaccharides was identified in Fourier transform infrared analysis (FTIR). The degradation of wood was observed through scanning electron microscopy (SEM). The energy dispersive X–ray spectroscopy (EDX) revealed the inclusion of minerals, such as calcium, silicon, iron, and sulfur, into archaeological wood structure during burial and subsequent interaction with the surrounding environment. Archaea may also be associated with detected silica in archaeological wood since several organosilicon compounds have been found in the crude extracts of archaeal cells. Archaeal species were isolated from water and sediment samples from various sites in El–Hamra Lake and identified as
Natronococcus
sp. strain WNHS2,
Natrialba hulunbeirensis
strain WNHS14,
Natrialba chahannaoensis
strain WNHS9, and
Natronococcus occultus
strain WNHS5. Additionally, three archaeal isolates were obtained from archaeological wood samples and identified as
Natrialba chahannaoensis
strain W15,
Natrialba chahannaoensis
strain W22, and
Natrialba chahannaoensis
strain W24. These archaeal isolates exhibited haloalkaliphilic characteristics since they could thrive in environments with high salinity and alkalinity. Crude extracts of archaeal cells were analyzed for the organic compounds using gas chromatography–mass spectrometry (GC–MS). A total of 59 compounds were identified, including free saturated and unsaturated fatty acids, saturated fatty acid esters, ethyl and methyl esters of unsaturated fatty acids, glycerides, phthalic acid esters, organosiloxane, terpene, alkane, alcohol, ketone, aldehyde, ester, ether, and aromatic compounds. Several organic compounds exhibited promising biological activities. FTIR spectroscopy revealed the presence of various functional groups, such as hydroxyl, carboxylate, siloxane, trimethylsilyl, and long acyl chains in the archaeal extracts. Furthermore, the archaeal extracts exhibited antioxidant effects. This study demonstrates the potential of archaeal extracts as a valuable source of bioactive compounds with pharmaceutical and biomedical applications.
Journal Article
Production, characterization and biomedical potential of biosurfactants produced by haloalkaliphilic archaea from Wadi El-Natrun, Egypt
by
Hegazy, Ghada E.
,
Alghamrawy, Basma T.
,
Sabry, Soraya A.
in
Anti-inflammatory
,
Anticancer
,
Antimitotic agents
2024
Extreme halophilic archaea that can live in high saline environments can offer potential applications in different biotechnological fields. This study delves into the fascinating field of halophilic archaea and their ability to produce biosurfactants. Some strains of haloarchaea were isolated from Wadi El-Natrun and were screened for biosurfactants production in a standard basal medium using emulsification index assay. Two strains were chosen as the potential strains for surface tension reduction. They were identified as
Natrialba
sp. BG1 and N3. The biosurfactants production was optimized and the produced emulsifiers were partially purified and identified using FTIR and NMR. Sequential statistical optimization, Plackett–Burman (PB) and Box–Behnken Designs (BBD) were carried out using 5 factors: oil, NaCl, casamino acids, pH, and inoculum size. The most significant factors were used for the next Response Surface Methodology experiment. The final optimal conditions for biosurfactants production were the inoculum size 2% pH 11 and NaCl 250 g/L, for
Natrialba
sp. BG1 and inoculum size 2.2%, pH 10 and NaCl 100 g/L for
Natrialba
sp. N3. The produced biosurfactants were tested for wound healing and the results indicated that
Natrialba
sp. BG1 biosurfactants is more efficient than
Natrialba
sp. N3 biosurfactants. Biosurfactants extracts were tested for their cytotoxic effects on normal cell line as well as on different cancer cells using MTT assay. The findings demonstrated that varying concentrations of the biosurfactants (31.25, 62.5, 125, 250, 500 and 1000 µg/mL) exhibited cytotoxic effects on the cell lines being tested. Additionally, the outcomes unveiled the presence of anti-inflammatory and antioxidant properties for both biosurfactants. Consequently, they could potentially serve as natural, safe, and efficient novel agents for combating cancer, promoting wound healing, and providing anti-inflammatory and antioxidant benefits.
Journal Article