Optimization of silver nanocrystals reduced from the functional molecules enriched Spirulina – A potent antibiotic against human and marine pathogen Vibrio parahaemolyticus

Abstract

Abstract Organic reduction of nanomaterials is an inexpensive and ecologically feasible method. The major challenge of this method is its optimization to improve efficiency. The reduction of metal ions with the conjugation, involves either through extraction from natural materials like plants, algae, fungus, and bacteria or by the action of micro-organisms (intracellular synthesis of these particles). The present investigation deals with the green synthesis of silver nanoparticles (SNPs) reduced by Spirulina platensis. The reduced nanoparticle synthesized by the microorganism was materialized to inhibit the pathogenic Vibrio parahaemolyticus isolated from the aquaculture system of Tamil Nadu. The highest percentage of distribution of V. parahaemolyticus was recorded in the farm water collected from shrimp farms of Nagapattinam than in the Cuddalore district. The presence of secondary metabolites in qualitative estimation and GCMS revealed the presence of 32 compounds in both acetone and methanol extract. The essential fatty acids eicosane was found to have antibiotic potency against shrimp infected with pathogenic bacteria. The synthesized Spirulina SNPs were characterized using UV-Vis spectrophotometer, EDAX, XRD, TEM and SEM. The analysis revealed a spherical structure without any agglomerates whose reduction absorption was at 200–450 nm. The good diffusion method showed inhibition of human and marine pathogen V. parahaemolyticus, exhibiting an inhibitory zone at 15.30 ± 2.21 and 15.19 ± 2.48 mm respectively. Thus, the Spirulina-mediated silver nanoparticles are found to be a simple, economical, and eco-friendly biomaterial to be a potent antibiotic against the pathogenic bacteria found in shrimps.