Browsing by Author "AlMunqedhi, Bandar M"

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Green synthesis, characterization, and evaluation of antibacterial activities of cobalt nanoparticles produced by marine fungal species Periconia prolifica
(Walter de Gruyter GmbH, 2023-10) Hodhod, Mohamed S; Gaafar, Abdel-Rhman Z; AlMunqedhi, Bandar M; Elzein, Abdalla
Bio-nanotechnology provided an ecofriendly synth- esis route for various metal nanoparticles by utilizing dif- ferent biological systems, especially microorganisms, which act as an alternative to the physical and chemical methods. Cobalt nanoparticles (CoNPs) were synthesized by Periconia prolifica (Anast.) from intertidal decayed wood samples from the mangrove tree Avicennia marina (Forsk.) of Tarout Island, located in the Arabian Gulf Sea of Saudi Arabia. CoNPs were characterized by X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and atomic force microscope. The extract of the culture of P. prolifica was used as a bio-reductant agent, during which the culturing process proved to have great potential to be applied on an industrial scale, as it was a time-saving, inex- pensive, and adequate amount of biomass being produced at the end of the process. A preliminary antibacterial test against one Gram-positive resistant bacteria (i.e., Methicillin-resistant Staphylococcus aureus) and other Gram-negative resistant bacteria was performed using a disk diffusion assay. The antibacterial results witnessed the key role that metal size plays in causing higher activity and also in causing severe damage to the bacterial cells by inactivating its membrane permeability, leading to bacterial cell death.
Microbial dynamics and dehydrogenase activity in tomato (Lycopersicon esculentum Mill.) rhizospheres: Impacts on growth and soil health across different soil types
(Walter de Gruyter GmbH, 2024-03) Suliman, Kamal Hassan; Gaafar, Abdel-Rhman Z; Abdelmalik, Abdelmalik M; AlMunqedhi, Bandar M; Elzein, Abdalla; Hodhod, Mohamed S
The dehydrogenase activity (DHA) in the rhizospheres of tomatoes grown in different soil types – Khor Abu-Habil (KA), Bara (B), and Greenhouse (Gr) – in North Kordofan, Sudan, was determined. In addition, the abundance of soil microbes in the tomato rhizospheres during the two growth stages, after 45 and 90 days (short and long term), was analyzed. The KA site (clay soil) showed the highest DHA (81.79 CFUs/g) followed by the B site (63.76 CFUs/g) (sandy loam) after 90 days of sowing, and the Gr site showed the lowest DHA (44.50 CFUs/g) (loamy sand soil) after 45 days. Moreover, the presence of high microbial activity (total density counts, total fungi, phosphatesolubilizing bacteria, Streptomycetes sp., Azotobacter sp., Azospirillum sp., and Pseudomonas sp. density counts) after 90 days and minimum microbial abundance after 45 days were identified at all sites. The measured growth parameters of fresh and dry weight, in addition to the rootto-shoot ratio, increased significantly at the same KA site dominated by a higher microbial density after 90 days. During the long term, the growth stage was positively affected by the abundance of adapted microbials that improve and enhance plant growth.