Biosynthesis, characterization, toxicity assessment and bio-efficacy of silver nanoparticles synthesized by Microbacterium mitrae in controlling early blight in tomato (Lycopersicon esculentum L.)

This study evaluated the biogenesis of silver nanoparticles (NPs) using Microbacterium mitrae and its possibilities against phytopathogens. Silver nanoparticles have been synthesized using a simple protocol and the synthesized NPs have been characterized using UV visible spectroscopy, particle size analyzer, transmission electron microscope (TEM). Small-sized, stable silver nanoparticles in the range of 10-25 nm have been reported. Their antimicrobial activity against three phytopathogens i.e. Alternaria solani, Thanatephorus cucumeris and Botryodiplodia theobromae, was studied. The nanoparticles showed effective antimicrobial activity against all the tested fungal pathogens under in vitro conditions. The genotoxicity of NPs was also studied using sister chromatid exchange analysis on human lymphocytes and no adverse effects were observed up to the concentration of 100µg/ml. Efficient control against early blight has been observed within cytotoxicity limits in pot study, preventing the disease outbreak in tomato plants.