The aim of our study was to examine the different concentrations of AuNPs as a new antimicrobial substance to control the pathogenic activity. The extracellular synthesis of AuNPs performed by using Phoma sp. as an endophytic fungus. Endophytic fungus was isolated from vascular tissue of peach trees (Prunus persica) from Baft, located in Kerman province, Iran. The UltraViolet-Visible Spectroscopy (UV–Vis spectroscopy) and Fourier transform infrared spectroscopy provided the absorbance peak at 526 nm, while the X-ray diffraction and transmission electron microscopy images released the formation of spherical AuNPs with sizes in the range of 10–100 nm. The findings of inhibition zone test of Au nanoparticles (AuNPs) showed a desirable antifungal and antibacterial activity against phytopathogens including Rhizoctonia solani AG1-IA (AG1-IA has been identified as the dominant anastomosis group) and Xanthomonas oryzae pv. oryzae. The highest inhibition level against sclerotia formation was 93% for AuNPs at a concentration of 80 μg/mL. Application of endophytic fungus biomass for synthesis of AuNPs is relatively inexpensive, single step and environmentally friendly. In vitro study of the antifungal activity of AuNPs at concentrations of 10, 20, 40 and 80 μg/mL was conducted against rice fungal pathogen R. solani to reduce sclerotia formation. The experimental data revealed that the Inhibition rate (RH) for sclerotia formation was (15, 33, 74 and 93%), respectively, for their corresponding AuNPs concentrations (10, 20, 40 and 80 μg/mL). Our findings obviously indicated that the RH strongly depend on AuNPs rates, and enhance upon an increase in AuNPs rates. The application of endophytic fungi biomass for green synthesis is our future goal.

The main goal of our study was to determine whether biosynthesized silver nanoparticles (SNPs) could be used as a novel antibacterial material in order to control soft rot in vegetables. Exudates from oak fruit were used in the green synthesis of SNPs. Postharvest soft rot disease in vegetables has resulted in significant crop losses all over the globe. Because managing Pectobacterium carotovorum subsp. carotovorum (Pcc), the causal agent of soft rot disease, is difficult due to its wide host range, developing innovative disease-management methods that do not involve the use of hazardous chemicals is a top priority for maintaining sustainable agriculture. The current research has found that silver nanoparticles (SNPs) have a detrimental effect on the progression of Pcc and soft rot disease in in vitro conditions. At SNPs’ sub-MIC, the greatest levels of inhibition against tissue maceration were 22, 19.8, 21.5, and 18.5 percent in potato, zucchini, carrot, and eggplant, respectively. SNP treatment of tubers and fruits had a noteworthy suppressive impact on soft rot disease symptoms as compared to controls. SNPs may be able to replace chemical pesticides in the management and prevention of soft rot disease in vegetables in postharvest settings, according to this study.

A study was conducted in the Guilan Province of Iran, using a variety of Actinomycetes species isolated from the rice fields, with the intention of identifying useful biocontrol agents to lessen rice sheath blight disease. The antagonistic effects against the rice pathogen agent were also assessed both in vitro and in vivo. The antifungal abilities of more than 30 Actinomycetes isolates against the Rhizoctonia solani Kühn (AG1-IA) were used. The biocontrol abilities of the most active isolates were studied in a greenhouse. The size of the inhibition zone against pathogen development and the most potent antagonist Actinomycetes isolates were determined based on the dual culture screening test findings. The ability to create hydrolytic enzymes including amylase, chitinase, protease, and lipase were shown by hydrolytic enzyme assays on the putative antagonists. Antifungal activities of Streptomyces isolates against fungus mycelia were also studied using SEM since, compared to the control grown mycelia and mycelia adjacent to the inhibition zone in the plate, tests revealed an unusual and deformed structure; in our opinion, the chitinase secreted can destroy fungal mycelium. Chloroform test showed that its antifungal effect persists upon exposure to chloroform. All possible isolates belonged to the Streptomyces species, according to the 16S rDNA molecular analysis of the majority of active isolates. Comparing isolates, G had the highest impact in reducing sheath blight disease. The Iranian strain of the Streptomyces has antifungal capabilities, highlighting its potential as a viable biocontrol agent to be used in an Integrated Disease Management (IDM) program to control the rice sheath blight disease.