Biogenic Silver Nanoparticles Produced by Soil Rare Actinomycetes and Their Significant Effect on Aspergillus-derived mycotoxins

Mohamed N Abd El-Ghany; Salwa A Hamdi; Shereen M Korany; Reham M Elbaz; Ahmed N Emam; Mohamed G Farahat

doi:10.3390/microorganisms11041006

Biogenic Silver Nanoparticles Produced by Soil Rare Actinomycetes and Their Significant Effect on Aspergillus-derived mycotoxins

Microorganisms. 2023 Apr 12;11(4):1006. doi: 10.3390/microorganisms11041006.

Authors

Mohamed N Abd El-Ghany¹, Salwa A Hamdi², Shereen M Korany^{3

4}, Reham M Elbaz^{3

5}, Ahmed N Emam^{6

7}, Mohamed G Farahat^{1

8}

Affiliations

¹ Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
² Zoology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
³ Botany and Microbiology Department, Faculty of Science, Helwan University, Cairo 11795, Egypt.
⁴ Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
⁵ Department of Biology, Faculty of Science, University of Bisha, P.O. Box 551, Bisha 61922, Saudi Arabia.
⁶ Refractories, Ceramics and Building Materials Department, Advanced Materials Technology & Mineral Resources Research Institute, National Research Centre (NRC), El Bohouth St., Dokki, Cairo 12622, Egypt.
⁷ Nanomedicine & Tissue Engineering Research Lab, Medical Research Centre of Excellence, National Research Centre, El Bohouth St., Dokki, Cairo 12622, Egypt.
⁸ Biotechnology Department, Faculty of Nanotechnology for Postgraduate Studies, Cairo University, Sheikh Zayed Branch Campus, Giza 12588, Egypt.

Abstract

The current investigation addressed the green synthesis of silver nanoparticles (AgNPs) using newly isolated silver-resistant rare actinomycetes, Glutamicibacter nicotianae SNPRA1 and Leucobacter aridicollis SNPRA2, and investigated their impact on the mycotoxigenic fungi Aspergillus flavus ATCC 11498 and Aspergillus ochraceus ATCC 60532. The formation of AgNPs was evidenced by the reaction's color change to brownish and the appearance of the characteristic surface plasmon resonance. The transmission electron microscopy of biogenic AgNPs produced by G. nicotianae SNPRA1 and L. aridicollis SNPRA2 (designated Gn-AgNPs and La-AgNPs, respectively) revealed the generation of monodispersed spherical nanoparticles with average sizes of 8.48 ± 1.72 nm and 9.67 ± 2.64 nm, respectively. Furthermore, the XRD patterns reflected their crystallinity and the FTIR spectra demonstrated the presence of proteins as capping agents. Both bioinspired AgNPs exhibited a remarkable inhibitory effect on the conidial germination of the investigated mycotoxigenic fungi. The bioinspired AgNPs caused an increase in DNA and protein leakage, suggesting the disruption of membrane permeability and integrity. Interestingly, the biogenic AgNPs completely inhibited the production of total aflatoxins and ochratoxin A at concentrations less than 8 μg/mL. At the same time, cytotoxicity investigations revealed the low toxicity of the biogenic AgNPs against the human skin fibroblast (HSF) cell line. Both biogenic AgNPs exhibited feasible biocompatibility with HSF cells at concentrations up to 10 μg/mL and their IC₅₀ values were 31.78 and 25.83 μg/mL for Gn-AgNPs and La-AgNPs, respectively. The present work sheds light on the antifungal prospect of the biogenic AgNPs produced by rare actinomycetes against mycotoxigenic fungi as promising candidates to combat mycotoxin formation in food chains at nontoxic doses.

Keywords: antifungal activity; biosynthesis; mycotoxin inhibition; mycotoxin production; rare actinomycetes; silver nanoparticles; spore germination.

Grants and funding

This research received no external funding.