Enrichment of Arthrospira platensis with silver nanoparticles: Effects on nanoparticle uptake and biomass accumulation

The incorporation of silver nanoparticles into cyanobacterium Arthrospira platensis biomass is emerging as a promising strategy to enhance its functional value. However, achieving a balance between efficient nanoparticle uptake and the preservation of biomass accumulation remains a key challenge. This study investigated the effects of two silver nanoparticles types - synthesized via electrical discharge in distilled water (AgNPs) and stabilized with potassium carbonate (AgNPs K₂CO₃) - on biomass accumulation, biochemical composition, oxidative stress markers, and nanoparticle uptake. Both nanoparticle types were effectively bioaccumulated, with retention efficiencies reaching up to 92 %, without entirely suppressing biosynthetic activity. AgNPs K₂CO₃ enhanced Arthrospira platensis biomass accumulation and antioxidant activity, while both nanoparticles' types reduced protein and carbohydrate content. Lipid levels in the biomass varied depending on nanoparticle type and their concentration. Notably, malondialdehyde levels remained comparable to the control, suggesting effective oxidative stress management. The combination of high silver uptake with preserved redox balance and acceptable biochemical parameters indicates that Arthrospira platensis biomass enriched with silver nanoparticles, particularly K₂CO₃-stabilized, can be considered for safe and controlled biotechnological applications.