Bacillus-Mediated Silver Nanoparticle Synthesis and Its Antagonistic Activity against Bacterial and Fungal Pathogens

Abstract

In this article, the supernatant of the soil-borne pathogen Bacillus mn14 was used as the catalyst for the synthesis of AgNPs. The antibacterial and antifungal activity of Bs-AgNPs was evaluated, in which S. viridans and R. solani showed susceptibility at 70 µL and 100 µL concentrations. Enzyme properties of the isolates, according to minimal inhibitory action and a growth-enhancing hormone–indole acetic acid (IAA) study of the isolates, were expressed in TLC as a purple color with an Rf value of 0.7. UV/Vis spectroscopy revealed the presence of small-sized AgNPs, with a surface plasmon resonance (SPR) peak at 450 nm. The particle size analyzer identified the average diameter of the particles as 40.2 nm. The X-ray diffraction study confirmed the crystalline nature and face-centered cubic type of the silver nanoparticle. Scanning electron microscopy characterized the globular, small, round shape of the silver nanoparticle. AFM revealed the two-dimensional topology of the silver nanoparticle with a characteristic size ranging around 50 nm. Confocal microscopy showed the cell-wall disruption of S. viridans treated with Bs-AgNPs. High-content screening and compound microscopy revealed the destruction of mycelia of R. solani after exposure to Bs-AgNPs. Furthermore, the Bs-AgNPs cured sheath blight disease by reducing lesion length and enhancing root and shoot length in Oryza sativa seeds. This soil-borne pathogen Bacillus-mediated synthesis approach of AgNPs appears to be cost-efficient, ecofriendly, and farmer-friendly, representing an easy way of providing valuable nutritious edibles in the future.

Sunlight-Mediated Green Synthesis of Silver Nanoparticles Using the Berries of Ribes rubrum (Red Currants): Characterisation and Evaluation of Their Antifungal and Antibacterial Activities

“…In contrast, biological synthesis is environmentally friendly, sustainable, and non-hazardous. Biological synthesis of NPs is carried out with algae [ 19 ], fungi [ 20 ], bacteria [ 21 ], and plants [ 22 ]. Nevertheless, again, among all of the biological methods, plant-mediated silver nanoparticle synthesis is the most preferred.…”

“…Synthesis of silver nanoparticles (AgNPs) has been reported from almost all parts of plants, including seeds and seed waste [ 24 , 25 ], arils [ 26 ], fruit and fruit waste [ 27 , 28 ], flowers [ 29 ], stems [ 30 ], roots [ 31 ] and leaves [ 32 ]. The green synthesised nanoparticles have shown potent cytotoxic, antifungal, and antibacterial activity against different cancer cell lines and several pathogenic isolates of bacteria and fungi [ 21 , 24 , 26 ]. Recently, AgNPs derived from aqueous extracts of mace arils showed strong inhibition of Fusarium oxysporum , Alternaria alternata , and Trichoderma harzianum , along with a few bacterial species [ 26 ].…”

Biofabrication of nanoparticles: sources, synthesis, and biomedical applications

“…Within 18 h of incubation, the aqueous silver ions (Ag + ) were converted to AgNPs when introduced to the cell-free supernatant of B. subtilis . The control showed no color change over the incubation time, whereas the yellow color turned brown ( Kabeerdass et al, 2021 ). The bacterial synthesis of nanoparticles has limitations.…”

Amalgamation of arbuscular mycorrhizal fungi and phosphate solubilizing bacteria on growth and yield of Solanum lycopersicum L.

“…To use the serial dilution plate technique, phosphobacteria were counted in the rhizosphere soils of several tomato-growing farms 41,42,43,44 . The soil samples were serially diluted to a concentration of 10 -4 .…”