Optimization of AgNPs production from Fusarium oxysporum H39 and its effectiveness as nanopesticides facing Pectobacterium carotovorum

In response to the increasing shortage of agrochemicals in developing countries, which directly impacts farmers' livelihoods, this study investigates the synthesis of silver nanoparticles (AgNPs) employ the enzymatic extract from a native strain of Fusarium oxysporum H39. These nanoparticles were assessed for their antibacterial efficacy facing potato tuber soft rot caused by Pectobacterium carotovorum. The optimal conditions for AgNP synthesis were determined to be a concentration of 3 mM, a pH of 10, and a temperature of 27°C over a 24-hour period. Under these conditions, spherical nanoparticles with an average size of 12.3 ± 4.3 nm were produced. FTIR analysis indicated the presence of organic compounds on the surface of the AgNPs, as evidenced by bands corresponding to C-O, C-N, and C-C bonds. The nanoparticles demonstrated significant nanopesticide activity facing the phytopathogenic bacterium P. carotovorum, with minimum inhibitory concentrations (MICs) of 25 ppm and 50 ppm identified through microdilution and macrodilution assays, respectively. Additionally, in controlled substrate tests, preventive treatment of tubers with a 100 ppm dose of AgNPs significantly reduced the weight of macerated tissue, the primary symptom of the disease.