Minimum inhibitory concentration of nano-silver bactericides for beneficial microbes and its effect on Ralstonia solanacearum and seed germination of Japanese Cucumber (Cucumis sativus)

Abstract

Background Plant growth-promoting rhizobacteria (PGPR) are highly promising biofertilizers that contribute to eco-friendly sustainable agriculture. There have been many reports on the anti-microbial properties of nanoparticles (NPs). Toxic effects of NPs under laboratory conditions have also reported; however, there is a lack of information about their uptake and mobility in organisms under environmental conditions. There is an urgent need to determine the highest concentration of NPs which is not detrimental for growth and proliferation of PGPR. Methods Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to measure the size and shape of NPs. Minimum inhibitory concentrations (MIC) of nano-silver on selected beneficial microbes and Ralstonia solanacearum were measured using the microdilution broth method. The percentage of seed germination was measured under in vitro conditions. Results NPs were spherical with a size of 16 ± 6 nm. Nano-silver at 12–40 mg l−1 inhibited the growth of bacteria. Seed application at 40 mg l−1 protected seeds from R. solanacearum and improved the rate of seed germination.

Biosynthesis of Silver Chloride Nanoparticles by Rhizospheric Bacteria and Their Antibacterial Activity against Phytopathogenic Bacterium Ralstonia solanacearum

“…The AgNPs exhibit their antimicrobial potential through multifaceted mechanisms due to their antimicrobial activity against a diverse and broad range of plant pathogens [ 45 ]. In this study, the biosynthesized AgNPs exhibited high inhibitory activity against growth, swarming, and swimming motility of R. solanacearum and indicted its potential applications against bacterial wilt disease, which is similar to a previous report [ 46 ]. Meanwhile, the mode of AgNPs action on bacterial cells was characterized by SEM on the basis of the morphological changes of cells, and the presence of nanoparticles was confirmed by EDS, providing evidence of direct physical interaction between nanoparticles and bacterial cells ( Figure 10 a,d).…”

Nanoparticles as Anti-Microbial, Anti-Inflammatory, and Remineralizing Agents in Oral Care Cosmetics: A Review of the Current Situation

“…Ag NPs are effective against Gram-positive and Gram-negative bacteria, and even against some antibiotic-resistant strains, but also against viruses and fungi (Table 1) [79][80][81][82]. In vitro, Ag NPs have an anti-microbial effect against Gram-negative bacteria such as Acinetobacter [83], Escherichia [84], Pseudomonas [85], and Salmonella [86]. These NPs also act against Gram-positive bacteria such as Bacillus [87], Enterococcus [88], Listeria [89], Staphylococcus [90], and Streptococcus [91].…”