Biomolecules-mediated synthesis of selenium nanoparticles using Aspergillus oryzae fermented Lupin extract and gamma radiation for hindering the growth of some multidrug-resistant bacteria and pathogenic fungi.

Biosynthesis of nanoparticles by fermented plants using microbes is an eco-friendly and cost-effective process. In this study, we used the fungus Aspergillus orayzae for the fermentation process. The aqueous extract of fermented Lupin (AEFL) possesses the ability to reduce selenium ion in the presence of gamma rays evidenced by the color changes to red. Elemental composition, surface morphology, size determenation, and identity of selenium nanoparticles (SeNPs) were verified by UV-Vis., TEM, DLS, XRD, EDX, SEM and FT-IR. Antimicrobial activity of SeNPs was tested towards multidrug-resistant (MDR) bacteria, and some pathogenic fungi. TEM with DLS analysis confirmed the formation of sphere isotropic, poly-dispersed SeNPs with average particle size 55.0 nm. The nucleation and mechanism of SeNPs production was discussed. Our results revealed that, gamma ray (30.0 kGy) was played a significant role in SeNPs synthesis. The synthesized SeNPs were active towards Acinetobacter calcoaceticus (15.0 mm ZOI) and Staphylococcus aurus (16.6 mm ZOI). Additionally, SeNPs were inhibiting Candida albicans (15.3 mm ZOI) and mycotoxin producing Aspergillus flavus (29.6 mm ZOI). Depending on the unique characteristics, and the novelty in biosynthesis process of SeNPs, it must be candidates in biomedicine, prevent food spoilage, cosmetics, and pharmaceutics as green antimicrobial agent.