Rhizopus oryzae-Mediated Green Synthesis of Magnesium Oxide Nanoparticles (MgO-NPs): A Promising Tool for Antimicrobial, Mosquitocidal Action, and Tanning Effluent Treatment

Abstract

The metabolites of the fungal strain Rhizopus oryaze were used as a biocatalyst for the green-synthesis of magnesium oxide nanoparticles (MgO-NPs). The production methodology was optimized to attain the maximum productivity as follows: 4 mM of precursor, at pH 8, incubation temperature of 35 °C, and reaction time of 36 h between metabolites and precursor. The as-formed MgO-NPs were characterized by UV-Vis spectroscopy, TEM, SEM-EDX, XRD, DLS, FT-IR, and XPS analyses. These analytical techniques proved to gain crystalline, homogenous, and well-dispersed spherical MgO-NPs with an average size of 20.38 ± 9.9 nm. The potentiality of MgO-NPs was dose- and time-dependent. The biogenic MgO-NPs was found to be a promising antimicrobial agent against the pathogens including Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans with inhibition zones of 10.6 ± 0.4, 11.5 ± 0.5, 13.7 ± 0.5, 14.3 ± 0.7, and 14.7 ± 0.6 mm, respectively, at 200 μg mL–1. Moreover, MgO-NPs manifested larvicidal and adult repellence activity against Culex pipiens at very low concentrations. The highest decolorization percentages of tanning effluents were 95.6 ± 1.6% at 100 µg/ 100 mL after 180 min. At this condition, the physicochemical parameters of tannery effluents, including TSS, TDS, BOD, COD, and conductivity were reduced with percentages of 97.9%, 98.2%, 87.8%, 95.9%, and 97.3%, respectively. Moreover, the chromium ion was adsorbed with percentages of 98.2% at optimum experimental conditions.

The Potency of Fungal-Fabricated Selenium Nanoparticles to Improve the Growth Performance of Helianthus annuus L. and Control of Cutworm Agrotis ipsilon

“…Data represented in Table 2 reported that the activity of Se-NPs against different instar larvae was dose and time-dependent. This result is compatible with others who reported that the toxicity of biosynthesized CuO-NPs, MgO-NPs, and Ag-NPs was dose-dependent [68][69][70]. Data analysis showed that the highest mortality percentages were achieved at the highest Se-NPs concentration (25 ppm), which were 34.3 ± 0.3%, 32.3 ± 0.3%, 46.0 ± 1.0%, 35.7 ± 0.6%, and 39.3 ± 0.3% for 1st to 5th instar larvae after 24 h. These mortality percentages were increased by increasing incubation time to reach 89.7 ± 0.3%, 78.3 ± 0.3%, 72.3 ± 0.6%, 63.7 ± 0.3%, and 68.7 ± 0.3% for the same instar larvae after 72 h (Table 1).…”

Evaluate the Toxicity of Pyrethroid Insecticide Cypermethrin before and after Biodegradation by Lysinibacillus cresolivuorans Strain HIS7

“…The biotechnological processes depending on biological entities are usually correlated with the environmental conditions which may have positive or negative impacts [30,31]. Therefore, the effects of the environmental parameters on biodegradation of cypermethrin using Lysinibacillus cresolivuorans strain HIS7 were investigated.…”

Antimicrobial and In-vitro Cytotoxic Efficacy of Betulinic Acid from the Callus, Regeneration, and Mother Plant of Dillenia indica L.

“…The plates were preserved in fridge for one hour before incubation for 24h (bacteria and unicellular fungi) at 35±2°C or 48h (multicellular fungi) at 28± 2°C. At the end of incubation period, the diameter of clear zone around each well was recorded by mm (Hassan et al, 2021). The experiment was achieved in triplicate.…”