Functional assessment of Streptomyces coelicolor secretome proteins associated with biogenic silver nanoparticles exhibiting multiple bioactive effects

: Streptomyces coelicolor spent fermentation medium was used to produce biogenic silver nanoparticles (ScoAgNPs) which were characterized for their size, morphology, stability, structure, macromolecular composition, and bioactivities. In particular, ATR-FTIR spectroscopy revealed the presence of lipids, nucleic acids, and proteins in ScoAgNPs. Differential shotgun proteomic analysis - comparing the ScoAgNP protein content with the S. coelicolor secretome - identified proteins accumulated in the biogenic nanomaterial. Bioinformatic analysis revealed their binding domains for nucleotides, carbon compounds, and metal compounds, as well as their predicted molecular functions. Additionally, in vitro assays revealed ScoAgNPs antimicrobial, antibiofilm, anticancer, and seed germination-promoting activities. These properties suggest that the ScoAgNPs could serve as promising bionanotechnological tools with applications in biomedicine and agriculture. Additionally, the identification of associated proteins provides novel insights into the biomolecular mechanisms underlying AgNP biogenesis, also paving the way for rational strategies aimed at optimizing production and enhancing bio-functionality.