Biosynthesized silver nanoparticles (Ag NPs) from isolated actinomycetes strains and their impact on the black cutworm, Agrotis ipsilon

Inas M Abou El-Enain; Enayat M Elqady; Eman El-Said; Hend H A Salem; Naglaa Fathi Badr; Ghada E Abd-Allah; Mohamed M Rezk

doi:10.1016/j.pestbp.2023.105492

Biosynthesized silver nanoparticles (Ag NPs) from isolated actinomycetes strains and their impact on the black cutworm, Agrotis ipsilon

Pestic Biochem Physiol. 2023 Aug:194:105492. doi: 10.1016/j.pestbp.2023.105492. Epub 2023 Jun 10.

Authors

Inas M Abou El-Enain¹, Enayat M Elqady², Eman El-Said², Hend H A Salem², Naglaa Fathi Badr², Ghada E Abd-Allah³, Mohamed M Rezk⁴

Affiliations

¹ Botany and Microbiology Dept., Faculty of Science, Al-Azhar University-Cairo, Cairo, Egypt.
² Zoology and Entomology Dept., Faculty of Science, Al-Azhar University-Cairo, Cairo, Egypt.
³ Plant Protection Research Institute, Agriculture Research Center, Cairo, Egypt.
⁴ Isotops Dept., Research Sector, Nuclear Materials Authority, Cairo, Egypt. Electronic address: DDrezk@Yahoo.com.

PMID: 37532318
DOI: 10.1016/j.pestbp.2023.105492

Abstract

Nanomaterials have been produced with the use of bio-nanotechnology, which is a low-cost approach. Currently, research is being conducted to determine whether actinomycetes isolated from Egyptian soil can biosynthesize Ag nanoparticles (Ag NPs) and characterized by using the following techniques: Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Fourier transforms infrared (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), UV-Vis spectroscopy and X-ray diffraction (XRD). The most promising actinomycetes isolate were identified, morphologically, biochemically, and molecularly. Streptomyces avermitilis Azhar A.4 was found to be able to reduce silver metal nanoparticles from silver nitrate in nine isolates collected from Egyptian soil. Toxicity of biosynthesized against 2nd and 4th larval instar of Agrotis ipsilon (Hufn.) (Lepidoptera: Noctuidae) was estimated. In addition, activity of certain vital antioxidant and detoxifying enzymes as well as midgut histology of treated larvae were also investigated. The results showed appositive correlations between larval mortality percentage (y) and bio-AgNPs concentrations (x) with excellent (R²). The 4th larval instar was more susceptible than 2nd larval instar with LC₅₀ (with 95% confirmed limits) =8.61 (2.76-13.89) and 26.44(13.25-35.58) ppml^-1, respectively of 5 days from treatment. The initial stages of biosynthesized AgNps exposure showed significant increases in carboxylesterase (CarE) and peroxidases (PODs) activity followed by significant suppression after 5 days pos-exposure. While protease activity was significantly decreased by increasing time post-exposure. Midgut histology showed abnormality and progressive damage by increasing time post exposure leading to complete destruction of midgut cells after 5 days from exposure. These results make biosynthesized AgNPs an appropriate alternative to chemical insecticide in A. ipsilon management.

Keywords: Actinomycetes; Black cutworm; Insecticide; Nanoparticles; Silver.

MeSH terms

Actinobacteria*
Actinomyces
Animals
Anti-Bacterial Agents / pharmacology
Larva
Metal Nanoparticles* / chemistry
Metal Nanoparticles* / toxicity
Plant Extracts / pharmacology
Silver / toxicity
Spectroscopy, Fourier Transform Infrared

Substances

Silver
Plant Extracts
Anti-Bacterial Agents