Biosynthesis of silver nanoparticle from pomelo (Citrus Maxima) and their antibacterial activity against acidovorax oryzae RS-2

Abstract

Silver nanoparticles (AgNPs), synthesized with plant materials, are considered to be an emerging field of agriculture for their eco-friendly and outstanding antibacterial attributes. In this study, we synthesized AgNPs using pomelo (Citrus maxima) fruit extract as a biological capping and reducing material. The particle size was determined as 11.3-12.8 nm by using UV-vis spectrophotometer, TEM and x-ray diffraction analysis. UV-vis spectrophotometer analysis also confirmed the formation of AgNPs in colloidal solution and showed a maximum absorption at 426 nm. Fourier transform infrared spectra was used to analysed the involvement of biological molecule in AgNPs synthesis. The minimum inhibitory concentration of AgNPs against Acidovorax oryzae strain RS-2 was determined as 25 μg ml −1 by agar well diffusion and bacterial growth assay. In addition, bacterial viability and swarming motility were significantly inhibited by AgNPs. Compared with the control, 25 μg ml −1 of AgNPs lower bacterial biofilm formation up to 68.24%. The bacterial cell wall damaged by AgNPs was observed t TEM. Furthermore, AgNPs treatment resulted into the down regulation of expression of many type VI secretion system related genes, suggesting that AgNPs also have an effect on the virulence of bacteria. The overall conclusion of this study suggests that AgNPs can play an important role in controlling A. oryzae.

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

“…The effect of synthesized AgCl-NPs solution on the swarming motility of cells of strain YY06 was examined in the LB broth supplemented with 0.7% ( w / v ) agar [ 53 ], and on swimming motility of the test bacteria in LB broth containing 0.3% agar [ 27 ]. Briefly, 5, 10, and 20 µg/mL −1 of synthesized AgCl-NP solution was mixed with both all LB media at 45 °C in separate petri plates, and 30 µL of the CFCS or ddH 2 O was used as controls.…”

“…To observe the interaction of the AgCl-NPs with pathogenic bacterium cells, we observed morphological changes on the surfaces of bacterial cells by SEM after the AgCl-NPs treated bacterial cells with final concentration of 2.0 µg/mL −1 with shaking (200 rpm) at 30 °C for 4 and 8 h. Briefly, suspensions of the treated bacteria were centrifuged at 6000 rpm for 10 min at 4 °C, washed with PBS at pH 7, post-fixated in 1% ( w / v ) osmium tetroxide, and dehydrated in a graded ethanol series (50%, 70%, 80%, 90%, 95%, and 100%), as described by [ 53 ]. The samples were attached to an aluminum stub and sputter-coated with gold, and then examined and photographed in an SEM (Zeiss Gemini SEM 300, Germany).…”

Silver Nanoparticles Biosynthesis, Characterization, Antimicrobial Activities, Applications, Cytotoxicity and Safety Issues: An Updated Review

“…The study revealed the importance of biosynthesized AgNPs, which can play a significant role in controlling Acidovorax oryzae strain RS-2. AgNPs downregulate the expression of type VI secretion system allied genes, which affects the virulence of bacteria [ 229 ]. Global efforts are underway to reduce the use of dangerous substances, especially chemical pesticides, in crop production.…”

Sunlight-Driven Synthesis of Silver Nanoparticles Using Pomelo Peel Extract and Antibacterial Testing

“…e flavonoids in pomelo peel extract can reduce silver ions into metallic Ag particles, and pectin can cap the formed AgNPs to protect them from further growth in size. To the best of our knowledge, only few studies used pomelo juice or pomelo peel extract to synthesize AgNPs, and none of these studies utilized sunlight to assist the formation of AgNPs [22][23][24]. erefore, we studied the formation of AgNPs in PPE upon exposure to direct sunlight and characterize the synthesized AgNPs, including their stability against electrolyte-induced agglomeration and antibacterial activity against four bacterial strains.…”