Mustafa A. Fawzy

Background: Heavy metals such as copper are known water pollutants that can be extremely harmful to the environment and pose serious risks to human health and aquatic organisms. The present study aimed to determine the efficiency of Achromobacter xylosoxidans isolated from waste soil as a cost-effective biosorbent for the removal of copper (II) (Cu ²⁺ ) ions from synthetic and real wastewater. Methods: The rate of copper biosorption by the bacterial strain was examined using batch experiments in 100 ml of aqueous solution, in which separate biosorption tests were performed for temperature (20–45 °C), initial pH (4–9), copper concentration (10–240 g L ⁻¹ ), contact time (0-150 min), and biosorbent dose (0.25-5.0 g L ⁻¹ ). Using the Box-Behnken design and response surface methodology, the biosorption of Cu ²⁺ ions by A. xylosoxidans biomass was also mathematically modeled to assess the interactive impacts of the independent factors of temperature, bacterial dosage, and initial metal ion concentration. Results: The analysis of variance (ANOVA) results revealed that the actual data were in line with the predicted data. Under the optimal circumstances of initial copper concentration of 112.35 mg L ⁻¹ , a biosorbent dose of 1.29 g L ⁻¹ , and a temperature of 34.8 °C, the copper biosorption efficiency of A. xylosoxidans was estimated to be 80.15%. The chemisorption of copper ions was controlled by second-order kinetic models, while the Langmuir model indicated monolayer biosorption with a maximum biosorption capacity of 106.38 mg g ⁻¹ . Thermodynamic characteristics revealed the spontaneous and endothermic nature of Cu ²⁺ biosorption. Desorption and regeneration tests showed that A. xylosoxidans could be desorbed with hydrochloric acid (HCl) to recover Cu ²⁺ after three successive biosorption-desorption cycles. High efficiency of the bacteria strain (88.55%) was also shown when applied to a real wastewater sample, indicating effective biosorbent performance in complex environments. Based on Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) data, it was suggested that the biosorption mechanism of copper ions involved a combination of complexation, electrostatic interactions, and ion-exchange. The efficiency of the strain in adsorbing Cu ²⁺ from contaminated synthetic and real wastewater strongly demonstrated the potential of A. xylosoxidans as a promising biosorbent in practical applications.

Novel benzenesulfonamide derivatives 2–5 were synthesized via base-catalyzed Claisen-Schmidt condensation and comprehensively evaluated for dual larvicidal efficacy against Wohlfahrtia magnifica and antibacterial activity against multidrug-resistant pathogens. Evaluation against W. magnifica larvae revealed that the thienyl-pyrazole-hybridized 5 exhibited the highest larvicidal potency, driving cumulative mortality to ~92% by day 4 at a concentration of 25 mg/g. Histopathological and ultrastructural analyses confirmed that the treatments caused extensive cuticular breakdown, myofibril fragmentation, severe mitochondrial swelling, and a progressive depletion of the collagen-like extracellular matrix from ~80% down to below 15%. Acridine orange fluorescence staining corroborated treatment-dependent apoptotic nuclear condensation and fragmentation. In antibacterial screenings, the pyrrolidine-pyrazole hybrid 2 exhibited selective, dose-dependent growth inhibition against Gram-negative Klebsiella pneumoniae (inhibition zones: 15–28 mm; MIC: 10 mg/mL) and Escherichia coli (inhibition zones: 9–16 mm; MIC: 25 mg/mL), while showing no activity against Gram-positive Staphylococcus aureus. Scanning electron microscopy (SEM) verified outstanding cell envelope rupture and structural collapse in treated bacteria. In vitro enzyme assays established that compound 2 significantly inhibited E. coli DNA gyrase B (IC₅₀ = 3.188 ± 0.11 µM) and topoisomerase IV (IC₅₀ = 14.288 ± 1.25 µM). Molecular docking simulations demonstrated strong target binding poses within respective ATP-binding cavities with docking scores of -10.88 and −9.98 kcal/mol. In silico ADMET profiling indicated good oral bioavailability, a high human intestinal absorption rate of 94.87%, and a favorable drug-likeness safety window. These quantitative findings identify compound 5 as a potent larvicidal agent and compound 2 as a highly promising multi-target antibacterial lead template for managing resistant Gram-negative infections.

The release of heavy metals into the environment as a result of industrial and agricultural activities represents one of the century’s most significant issues. Cobalt is a hazardous metal that is employed in a variety of industries. In this study, response surface methodology (RSM) combined with Box–Behnken design (BBD) was utilized to optimize the Co(II) ion removal from synthetic wastewater by the brown macroalga Padina pavonica. The influence of three factors, namely algal inoculum size, pH, and initial metal concentration, was assessed in optimization studies. RSM proposed a second-order quadratic model with a p-value of 2 of 0.984 for P. pavonica. According to the data related to RSM optimization, the maximum percentage of Co(II) removal of 84.3% was attained under the conditions of algal inoculum size of 5.98 g/L, pH of 6.73, and initial Co(II) concentration of 21.63 mg/L. The experimental data from the biosorption process were fitted well with the Langmuir, Freundlich, and Temkin isotherm models. The maximal Co(II) adsorption capacity was estimated using the Langmuir model to be 17.98 mg/g. Furthermore, the pseudo-second-order kinetic model was shown to have the best fit for Co biosorption by P. pavonica, showing that the mechanism of Co(II) biosorption was chemisorption controlled by surface biosorption and intra-particle diffusion. Thermodynamic parameters were also investigated to evaluate the Gibbs free energy for the Co(II) ion, which was positive, showing that the biosorption process is nonspontaneous and exothermic, and the cobalt biosorption rate decreases with increasing temperature. Algal biomass was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. These analyses revealed the biosorbent’s diverse functional groups and porous, rough appearance. Therefore, P. pavonica can be used to implement sustainable, eco-friendly, and acceptable solutions to water pollution problems.

The pollution of aquatic bodies by synthetic dyes is regarded as one of the most significant environmental issues, which has prompted greater research into effective and sustainable removal techniques. Even though there have been major efforts in the previous few decades, more study is still necessary to fully examine the long-term performance and usable applicability of adsorbents and different adsorption techniques for the removal of dye. In the present study, a brown marine macroalga Sargassum muticum was used as an effective and sustainable biosorbent for the crystal violet (CV) dye removal from aqueous solutions. The biosorbent was characterized by analysis of SEM, EDX, and FTIR. In order to evaluate the optimum conditions of CV biosorption, several parameters have been examined as a function of contact time, algal dose, initial concentration of CV, and pH. The maximum CV removal was obtained at 60 min contact time, 10 g/L algal dosage, 30 mg/L initial concentration of CV, and pH 6. The isothermal models of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin are best explained the equilibrium data obtained. At the optimum conditions, the maximum biosorption capacity of the algal biomass achieved from the Langmuir model was 39.1 mg/g. The kinetic adsorption models were also better explained using the pseudo-second-order and Elovich model, and the effect of the boundary layer was indicated using the intraparticle diffusion model as well as the chemisorption-controlled biosorption process. Thermodynamically, the process of CV biosorption was shown to be random, spontaneous, and endothermic. Furthermore, the proposed mechanism of CV dye biosorption onto algal biomass is regulated by hydrogen bond formation, electrostatic interaction, and ion exchange. These findings revealed that the biomass of S. muticum is a sustainable and promising material for the biosorption of water pollutants.

Due to their low cost and ability to synthesize lipids for sustainable biodiesel production, oleaginous fungus has recently gained more prominence than other microorganisms. The new oleaginous fungus Aspergillus carneus OQ275240’s dry biomass, lipid content, and lipid yield were all optimized in this work, using the response surface methodology-based Box–Behnken design. Analysis of variance (ANOVA) was also used to examine the experimental data, and multiple regression analysis was used to fit the data to a second-order polynomial equation. Three independent variables, such as the concentration of yeast, glucose, and phosphorus, were examined for their mutual impacts. Maximum dry biomass (0.024 g/50 mL), lipid content (36.20%), and lipid yield (8.70 mg/50 mL) were achieved at optimal concentrations of 2.68 g/L of yeast, 20.82 g/L of glucose, and 0.10 g/L of phosphorus, respectively, showing that the actual data and predictions of the models were in good agreement. A. carneus OQ275240 has a favorable fatty acid profile that can be used to successfully create biodiesel, as shown by the presence of palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1) in its fatty acid methyl esters (FAMEs) profile. Furthermore, the qualities of the biodiesel were investigated, and it was found that they fell within the parameters established by the international specifications EN 14214 (Europe) and ASTM D6751-08 (United States). These findings point to the newly evaluated filamentous fungal strain as a potential feedstock for the production of high-quality biodiesel.

Chemotherapy is an aggressive form of chemical drug therapy aiming to destroy cancer cells. Adjuvant therapy may reduce hazards of chemotherapy and help in destroying these cells when obtained from natural products, such as medical plants. In this study, the potential therapeutic effect of Rosa damascena callus crude extract produced in vitamin-enhanced media is investigated on colorectal cancer cell line Caco-2. Two elicitors, i.e., L-ascorbic acid and citric acid at a concentration of 0.5 g/L were added to the callus induction medium. Callus extraction and the GC–MS analysis of methanolic crude extracts were also determined. Cytotoxicity, clonogenicity, proliferation and migration of Caco-2 colorectal cancer cells were investigated using MTT cytotoxicity, colony-forming, Ki-67 flow cytometry proliferation and Migration Scratch assays, respectively. Our results indicated that L-ascorbic acid treatment enhanced callus growth parameters and improved secondary metabolite contents. It showed the least IC50 value of 137 ug/mL compared to 237 ug/mL and 180 ug/mL in the citric acid-treated and control group. We can conclude that R. damascena callus elicited by L-ascorbic acid improved growth and secondary metabolite contents as well as having an efficient antiproliferative, anti-clonogenic and anti-migratory effect on Caco-2 cancer cells, thus, can be used as an adjuvant anti-cancer therapy.

In this study, Rosa damascena leaf powder was evaluated as a biosorbent for the removal of copper from aqueous solutions. Process variables such as the biosorbent dose, pH, and initial copper concentration were optimized using response surface methodology. A quadratic model was established to relate the factors to the response based on the Box–Behnken design. Analysis of variance (ANOVA) was used to assess the experimental data, and multiple regression analysis was used to fit it to a second-order polynomial equation. A biosorbent dose of 4.0 g/L, pH of 5.5, and initial copper concentration of 55 mg/L were determined to be the best conditions for copper removal. The removal of Cu²⁺ ions was 88.7% under these optimal conditions, indicating that the experimental data and model predictions were in good agreement. The biosorption data were well fitted to the pseudo-second-order and Elovich kinetic models. The combination of film and intra-particle diffusion was found to influence Cu²⁺ biosorption. The Langmuir and Dubinin–Radushkevich isotherm models best fit the experimental data, showing a monolayer isotherm with a q_max value of 25.13 mg/g obtained under optimal conditions. The thermodynamic parameters showed the spontaneity, feasibility and endothermic nature of adsorption. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the biosorbent before and after Cu²⁺ biosorption, revealing its outstanding structural characteristics and high surface functional group availability. In addition, immobilized R. damascena leaves adsorbed 90.7% of the copper from aqueous solution, which is more than the amount adsorbed by the free biosorbent (85.3%). The main mechanism of interaction between R. damascena biomass and Cu²⁺ ions is controlled by both ion exchange and hydrogen bond formation. It can be concluded that R. damascena can be employed as a low-cost biosorbent to remove heavy metals from aqueous solutions.

Methyl violet 2B dye is a major contaminant that is detrimental to both humans and aquatic microorganisms, thus it should be eliminated from water. In the current investigation, the biosorption of methyl violet 2B dye onto the brown seaweed Cystoseira tamariscifolia biomass as a sustainable low-cost biosorbent was examined by varying biosorption parameters. Biomass dosage of 7 g/L, pH 6, a temperature of 45 °C, a 60 min contact time, and a 30 mg/L initial dye concentration were determined to be the optimum biosorption conditions. Data obtained were interpreted by thermodynamic, isothermal, and kinetic models. The thermodynamic studies demonstrated that the process of dye biosorption was random and endothermic. The data were best described by Langmuir, Dubinin–Radushkevich, and Temkin models. According to the Langmuir equation, the maximal biosorption capacity (q_max) was 10.0 mg/g. Moreover, the pseudo-second-order mechanism is dominant, and chemical biosorption might represent the rate-controlling stage in the biosorption process. However, intraparticle diffusion revealed a boundary layer effect. A scanning electron microscope, energy-dispersive X-ray spectroscopy, the point of zero charge, and Fourier Transform Infra-Red were applied to characterize the algal biomass, exhibiting its remarkable structural properties and the availability of several functional groups. Additionally, ion exchange, electrostatic force, and hydrogen bonding formation are all proposed as biosorption mechanisms. As a result, C. tamariscifolia was evaluated to be a sustainable biosorbent for dye biosorption from aqueous solutions.

The aim of this study was to assess the efficiency of Spirulina platensis for removing Zn²⁺ ions from the aqueous solutions. The optimized conditions of 4.48 g/L algal dose, pH of 6.62 and initial zinc concentration of 29.72 mg/L obtained by response surface methodology were employed for Zn²⁺ biosorption by S. platensis and up to 97.90% Zn²⁺ was removed, showing that there is a favorable harmony between the experimental data and model predictions. Different kinetic and equilibrium models were used to characterize the biosorption manner of Spirulina as a biosorbent. The kinetic manner of Zn²⁺ biosorption was well characterized by the pseudo-second-order, implying that the adsorption process is chemical in nature. The Langmuir and Dubinin–Radushkevich isotherm models were best fit to the equilibrium data. The maximum adsorption capacity of the Langmuir monolayer was 50.7 mg/g. Furthermore, the thermodynamic analysis revealed that Zn²⁺ biosorption was endothermic, spontaneous and feasible. As a result of biosorption process, FTIR, SEM, and EDX investigations indicated noticeable alterations in the algal biomass’s properties. Therefore, the dried Spirulina biomass has been shown to be cost-effective and efficient for removing the heavy metals, particularly zinc ions from wastewater, and the method is practicable, and environmentally acceptable.