الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
This study investigated the biosynthesis of selenium nanoparticles (SeNPs)
using endophytic fungi isolated from eight plant species collected from different
locations in Egypt representing diverse habitats. A total of tewenty fungal
isolates were recovered and initially classified based on morphological and
microscopical examination into 6 genera - Aspergillus, Alternaria, Fusarium,
Mucor, Penicillium, and Rhizopus. The twenty fungal isolates were screened for
their ability to extracellularly synthesize SeNPs in selenite-amended media,
with eight isolates showing evidence of production. Two isolates - Penicillium
citrinum and Rhizopus arrhizus - were selected for further characterization and
optimization of SeNP production. Both fungi could tolerate up to 40mM
selenite and reduced over 99% of 3mM selenite to elemental selenium under
optimal conditions as determined by ICP-MS.
The biosynthesis of SeNPs extracellularly by both fungi was frstly
distinguished by the appearance of red color, then it was confrmed by an
absorption peak in UV–Vis spectrum. The crystallinity and crystalline size of
mycosynthesized SeNPs were also studied by XRD analysis. The difraction
peaks for the SeNPs synthesized by both fungal strains confrm the hexagonal
crystalline structure. SeNPs synthesized were spherical in shape with sizes
between 50-80nm as revealed by TEM imaging. FTIR spectra of the two types
of mycosynthetic SeNPs revealed vibrational bands of diferent functional
groups in the range of (4000–400 cm−1) suggesting a mechanism for the
process of SeNP synthesis by both fungi. FTIR spectral analysis manifested the
presence of biomolecules and functional groups such as hydroxyl, amine, and
lipids with SeNPs that have a role as reducing agents to convert selenite to
elemental selenium, and as capping agents to avoid their agregation.