Antibacterial synergy of Tritirachium oryzae-produced silver nanoparticles with different antibiotics and essential oils derived from Cupressus sempervirens and Asteriscus graveolens (Forssk)

Purpose: To carry out eco-friendly biosynthesis of fungi-derived silver nanoparticles (AgNPs) and investigate their antibacterial synergies with essential oils (EOs) of Asteriscus graveolens (Forssk.) Less. and Cupressus sempervirens. Methods: Biosynthesis of AgNPs was carried out using a cell-free filtrate of Tritirachium oryzae. The biosynthesized AgNPs characteristics were assessed using different methods, including ultravioletvisible spectrophotometry (UV), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Results: Obvious synergistic effects were observed between AgNPs and chloramphenicol, vancomycin, nitrofurantoin or tetracycline with Pseudomonas aeruginosa, through increases in fold area of inhibition (IFAs) within the range of 2.4 to 9.0. Synergistic interactions were also seen between AgNPs and the antibiotics used, depending on the strain. Increase in IFA ranged from 1- to 3-fold for S. aureus, E. coli and P. aeruginosa. Similarly, combinations of AgNPs, EO of A. graveolens and cefotaxime, nitrofurantoin or amoxicillin against P. aeruginosa led to 10-, 3- and 10-fold synergy, respectively. In contrast, the use of AgNPs and trimethoprim, tetracycline or amoxicillin against E. coli led to 1 to 6-fold synergy. The best synergistic capacity resulted from AgNPs and the EO of C. sempervirens and trimethoprim against S. epidermidis, which yielded 29-fold increase in IFA. The use of combination of AgNPs and vancomycin against P. aeruginosa led to 16.4-fold enhancement of IFA. Conclusion: The findings can potentially lead to the development of a new perception of antibacterial agents (innovative medications) involving the incorporation of nanoparticles (NPs) or new materials that potentially synergize with antibiotics, NPs and the EOs of different plants

Metal Toxicity Reduction on Seed Germination and Seedling Growth of Raphanus sp. and Arabidopsis sp. Using Date Seed Biochar

The date seeds (DS) biochar produced at 550°C was found to be appropriate for remediation of metal-contaminated water. This was evident in the data, which showed that applying the biochar to Raphanus sp. and Arabidopsis sp. reduced metal stress and toxicity. The LC50 of all tested metals solutions on seed germination was increased significantly (P<0.05) in Raphanus sp. by 10.4, 2.3, 5, 1.8, and 3 folds, respectively, for Cu, Zn, Cd, Pb, and metals combination, and by 5, 3.4, 6, 5.5, and 2.5 folds in Arabidopsis sp. For seedling growth, the DS biochar enhanced the LC50 significantly (P<0.05) of the same metals in Raphanus sp. by 9.6, 9.2, 13.8, 12.1, and 1.6 folds, and in Arabidopsis sp. by 7, 3, 2.3, 2.9, and 2.7 folds, respectively. The LC of all metals was increased by 1.5 to 8 times and 1.5 to 12 times, respectively, for the seed germination and seedling growth of Raphanus sp. and Arabidopsis sp. Both plants were able to grow shoots at higher metal concentrations when the DS biochar was employed, as compared to the case when no DS biochar was utilized. In terms of shoot length, similar results were achieved, with the DS biochar application significantly enhancing shoot length (P<0.05), as compared to the case when no biochar was applied. Despite the fact that Arabidopsis sp. was more sensitive to metals than Raphanus sp., both plants raised their RGR and TI and reduced their phytotoxicity values in all metals following the DS biochar application, and sprouted at higher metal concentrations than before. These findings introduce a successful eco-friendly adsorbent for metal removal from aquatic environments, paving the way for more investigations

Biochar as a Cadmium Scavenger in the Aquatic Environment Remediation: Date Seeds as Raw Material

It was found that date seeds are suitable for biochar production due to their low moisture content 8.92%, low ash yield 1.05%, and high organic matter content 78.3%. The biochar was produced by pyrolysis at 350, 450 and 550°C. The effect of pyrolysis temperature on the physicochemical characteristics of biochar was investigated. It was found that the porosity, water holding capacity, ash content, pH, organic matter, fixed carbon, and the elemental content of Na, K, Ca, Mg, Fe, Mn, P, Zn, Ba, Cr, Cu, Ni, Pb, Ti, and V were increased along with pyrolysis temperature. Meanwhile, the biochar yield, bulk density, and the total content of N and S were decreased. The biochar was tested as a sustainable adsorbent to investigate the adsorption of Cd from contaminated water. The adsorption isotherms of Cd on biochar were determined based on Langmuir equation. The maximum adsorption of Cd at 25°C and pH 7 were 667, 714, and 833 mg/kg for the biochars produced at 350, 450, and 550°C, respectively. On the basis of the physicochemical characteristics of the biochar and the findings from Langmuir equation that showed the biochar produced at 550°C has the highest adsorption capacity for Cd, the desorption/adsorption experiment was carried out using the biochar produced at 550°C. The adsorption of Cd by biochar was directly proportional to the Cd concentrations. It was increased from 0.009 mmol/0.5g at 0.01 mmol Cd to 0.12 mmol/0.5g at 0.2 mmol Cd concentration. The desorption of Cd from biochar was increased proportionally to cadmium concentrations from 0.01 to 0.05 mmol and became constant above 0.05 mmol, regardless of the increment of cadmium concentrations. High retention potential for the cadmium that adsorbed within the biochar was proven in this study with desorption/adsorption percentage of 16%. These findings provide a successful example of date seeds converting into the sustainable adsorbent for Cd removal from aquatic environment to achieve the conception of eco-friendly production, which should be studied further

Growth Kinetics and Toxicity of Pseudomonas fredriksbergsis Grown on Phenol as Sole Carbon Source

Phenol is one of the main pollutants that have a serious impact on the environment and can even be very critical to human health. The biodegradation of phenol can be considered an increasingly important pollution control process. In this study, the degradation of phenol by Pseudomonas fredriksbergsis was investigated for the first time under different growth conditions. Six different initial concentrations of phenol were used as the primary substrate. Culture conditions had an important effect on these cells' ability to biodegrade phenol. The best growth of this organism and its highest biodegradation level of phenol were noticed at pH 7, temperature 28 °C, and periods of 36 and 96 h, respectively. The highest biodegradation rate was perceived at 700 mg/L initial phenol concentration. Approximately 90% of the phenol (700 mg/L) was removed in less than 96 hours of incubation time. It was found that the Haldane model best fitted the relationship between the specific growth rate and the initial phenol concentration, whereas the phenol biodegradation profiles time could be adequately described by the modified Gompertz model. The parameters of the Haldane equation are: $0.062 h^{−1}$, 11 ppm, and 121 ppm for Haldane’s maximum specific growth rate, the half-saturation coefficient, and the Haldane’s growth kinetics inhibition coefficient, respectively. The Haldane equation fitted the experimental data by minimizing the sum of squared error (SSR) to $1.36×10^{-3}$

Synergistic Effects of AgNPs and Biochar: A Potential Combination for Combating Lung Cancer and Pathogenic Bacteria

The synthesis of reliable biological nanomaterials is a crucial area of study in nanotechnology. In this study, Emericella dentata was employed for the biosynthesis of AgNPs, which were then combined with synthesized biochar, a porous structure created through biomass pyrolysis. The synergistic effects of AgNPs and biochar were evaluated through the assessment of pro-inflammatory cytokines, anti-apoptotic gene expression, and antibacterial activity. Solid biosynthesized AgNPs were evaluated by XRD and SEM, with SEM images revealing that most of the AgNPs ranged from 10 to 80 nm, with over 70% being less than 40 nm. FTIR analysis indicated the presence of stabilizing and reducing functional groups in the AgNPs. The nanoemulsion’s zeta potential, hydrodynamic diameter, and particle distribution index were found to be −19.6 mV, 37.62 nm, and 0.231, respectively. Biochar, on the other hand, did not have any antibacterial effects on the tested bacterial species. However, when combined with AgNPs, its antibacterial efficacy against all bacterial species was significantly enhanced. Furthermore, the combined material significantly reduced the expression of anti-apoptotic genes and pro-inflammatory cytokines compared to individual treatments. This study suggests that low-dose AgNPs coupled with biochar could be a more effective method to combat lung cancer epithelial cells and pathogenic bacteria compared to either substance alone