Toxicity Evaluation, Plant Growth Promotion, and Anti-fungal Activity of Endophytic Bacteria-Mediated Silver Nanoparticles.

Abstract

In recent years, the uses of silver nanoparticles have increased, which lead to nanoparticles discharge into aquatic bodies which may, if not well controlled, have harmful effect on different organisms. This calls for the need to constantly evaluate the toxicity level of nanoparticles. In this study, green biosynthesized silver nanoparticles mediated by endophytic bacteria Cronobacter sakazakii (CS-AgNPs) were subjected to toxicity evaluation by brine shrimp lethality assay. The ability of CS-AgNPs to improve plant growth by nanopriming of Vigna radiata L seeds treated with different concentrations (1ppm, 2.5ppm, 5ppm and 10ppm) in order to enhance biochemical constituents was investigated, also its inhibitory effect to growth of phytopathogenic fungi Mucor racemose was examined. Results showed that Artemia salina treated with CS-AgNPs exhibited good hatching percentage and LC50 value of 688.41µg/ml when Artemia salina eggs were exposed to CS-AgNPs during hatching. Plant growth was enhanced at 2.5ppm CS-AgNPs, with increased photosynthetic pigments, protein, and carbohydrate content. This study suggests that silver nanoparticles synthesized via endophytic bacteria Cronobacter sakazakii are safe to use and can be utilized as means of combating plant fungal pathogens.