scholarly journals Antimicrobial activities of bio-synthesized silver nanoparticles on strains of clavibacter michiganensis subsp. michiganensis

2019 ◽  
Vol 37 (2) ◽  
pp. 1-10
Author(s):  
A. R. Oloyede ◽  
O. T. Familola ◽  
O. I. Sonde ◽  
J. O. Ossai ◽  
A. O. Wahab
Keyword(s):  
Silver Nanoparticles ◽  
Inhibitory Activity ◽  
Tomato Plant ◽  
Antibacterial Activities ◽  
Clavibacter Michiganensis ◽  
Ag Nps ◽  
Canker Disease ◽  
Clavibacter Michiganensis Subsp ◽  
Zones Of Inhibition ◽  
Uv Visible

Silver nanoparticles (Ag-NPs) have been known to possess unique antimicrobial properties which help in medicine and water treatment, but their potentials in agriculture have not been fully utilized. This study was conducted to determine the inhibitory activity of bio-synthesized Silver nanoparticles on strains of Clavibacter michiganensis subsp. Michiganensis, causative agents of canker disease of tomato plant. The Ag-NPs were synthesized using Cladosporium cladosporioides, leaf extracts of Azadirachta indica and Vernonia amygdalina. The synthesized silver nanoparticles were characterized using UV-visible absorption spectroscopy. The antibacterial activities of bio-synthesized Ag-NPs on strains of C. michiganensis subsp. michiganensis were evaluated using agar well diffusion method. UV-visible spectroscopic analysis revealed rapid reduction of silver ions by C. cladosporioides, A. indica and V. amygdalina extracts where surface Plasmon absorption maxima were observed at 400nm – 450nm from the UV-visible spectra. The in-vitro antibacterial activities revealed that Ag-NPs synthesized using V. amygdalina and A. indica extracts inhibited the growth of C. michiganensis subsp. michiganensis strains with zones of inhibition ranging from 15.70 mm - 24.70mm and 21.00mm – 30.00mm, respectively, while those synthesized using C. cladosporioides showed zones of inhibition ranging from 0.00mm – 12.00mm. Growth curves of C. michiganensis subsp. michiganensis strains in the presence of biosynthesized Ag-NPs showed inhibition of growths after 4 – 10 hours of exposure. The results of this study indicated that the bio-synthesized silver nanoparticles could be effective in controlling bacterial canker disease of tomato plant caused by strains of C. michiganensis subsp. michiganensis thereby reducing the toxic effects of chemical bactericides on important agricultural products.Keywords: Silver nanoparticles; inhibitory activity; canker, tomato; zones of inhibition

Preparation of Triangular Silver Nanoparticles Using Polyvinyl Pyrrolidone with Different Concentration

2013 ◽  
Vol 873 ◽  
pp. 206-210
Author(s):  
Kai Li ◽  
Rao Fu ◽  
Qing Ran Gao ◽  
Ai Wei Tang ◽  
Ying Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Driving Force ◽  
Ostwald Ripening ◽  
Polyvinyl Pyrrolidone ◽  
Protective Agent ◽  
Ag Nps ◽  
Transmission Electron ◽  
Uv Visible

This paper continues our previous work on preparation of triangular silver nanoparticles. The method proceeds with reaction of silver nitrate with hydrazine hydrate in the presence of polyvinyl pyrrolidone in aqueous solution. Effects of the concentration of PVP on the morphologies of Ag NPs were systematically investigated. The obtained Ag NPs were characterized by transmission electron microscopy and UV-visible spectrophotometer. The results showed that, triangular Ag NPs with edge lengths in the range of 50-200 nm were obtained using PVP as protective agent with lower concentration. As the concentration of PVP increased, spherical Ag NPs with their sizes about 6.2 nm were prepared and triangular Ag NPs were not obtained. The formation mechanism of triangular Ag NPs has been studied. Ostwald ripening is the driving force on the conversion of spherical Ag NPs to triangular Ag NPs in the presence of PVP.

scholarly journals Nanocatalytic Activity of Silver Nanoparticles (Ag-Nps) Fabricated using Camellia sinensis (Linn) Tender Leaf Extract and their Characterization

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pancreatic Enzyme ◽  
Alpha Amylase ◽  
Assay Method ◽  
Ag Nps ◽  
Visible Absorption ◽  
Biological Reduction ◽  
Vis Spectroscopy ◽  
Uv Visible

Silver nanoparticles (Ag-NPs) were prepared by the biological reduction method. Green tea extract was taken as a reducing and stabilizing agent and silver nitrate as the metal precursor for nanoparticle synthesis. The formation of the silver nanoparticles was monitored visually and using UV-Visible absorption spectroscopy. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, FTIR, Zeta sizer, Zeta potential, and antimicrobial studies. Silver nanoparticles were also subjected to investigate nanocatalytic activity with standard pancreatic alpha-amylase and bacterial amylase enzyme by the DNS assay method. UV-Vis spectroscopy revealed the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 430 nm. Four major functional groups of bio-molecules such as phenol, carboxylic acid, protein, and alkyl group were recorded in FTIR spectra. The size of the nanoparticles ranges between 5nm and 150nm. The average size and size distribution of silver nanoparticles is 59.66nm. The zeta potential of the silver nanoparticle is negatively charged and rendered as a sharp peak at -31.7mV. Antimicrobial activity of silver nanoparticles exhibited the highest inhibition against Gram-negative bacteria than Gram-positive bacteria and yeast pathogens. Starch hydrolysis of Ag-NPs was studied with pancreatic alpha-amylase (tailor made), crude and purified bacterial amylase enzyme. The formation of reducing sugar was increased about 40-fold for a purified enzyme, 11-fold for the pancreatic enzyme, and 6-fold for crude bacterial enzyme incorporated with Ag-NPs over control. The present studies recommended that Ag-NPs have a significant role in the degradation of starch into reducing sugars by acting as a nanocatalyst.

scholarly journals Clavibacter michiganensis subsp. capsici subsp. nov., causing bacterial canker disease in pepper

2016 ◽  
Vol 66 (10) ◽  
pp. 4065-4070 ◽  
Author(s):  
Eom-Ji Oh ◽  
Chungyun Bae ◽  
Han-Beoyl Lee ◽  
In Sun Hwang ◽  
Hyok-In Lee ◽  
...  
Keyword(s):  
Bacterial Canker ◽  
Clavibacter Michiganensis ◽  
Canker Disease ◽  
Clavibacter Michiganensis Subsp

scholarly journals Copolymerization of Quinazolinone Derivatives With Styrene, Methyl Methacrylate and Their Silver Nanocomposites for Biological Applications

2021 ◽  
Author(s):  
Karim Samy El-Said ◽  
Ahmed Ahmed El-Barbary ◽  
Hazem M. ElKholy ◽  
Ahmed S. Haidyrah ◽  
Mohamed Betiha ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Silver Ions ◽  
Xrd Analysis ◽  
Antibacterial Activities ◽  
Mice Model ◽  
Ag Nps ◽  
Silver Nanocomposites ◽  
Amorphous Structures

Reaction of 2-mercapto-3-phenylquinazolin-4(3H)-one (MPQ) with both 4-vinyl benzyl chloride and allyl bromide furnished the reactive heterocyclic monomers 3-phenyl-2-((4-vinylbenzyl) thio) quinazolin-4(3H)-one (PVTQ) and 2-(allylthio)-3-phenylquinazolin-4(3H)-one (APQ), respectively. Copolymerization of PVTQ monomer with styrene and methyl methacrylate in the presence of 2,2′-azobisisobutyronitrile (AIBN) afforded the copolymers PS-co-PPVTQ and PMMA-co-PPVTQ, respectively. Similarly, copolymerization of monomer APQ with styrene and methyl methacrylate (MMA) afforded the copolymers PS-co-PAPQ and PMMA-co-PAPQ, respectively. The resulted copolymers were characterized by using FT-IR, 1H-NMR and GPC techniques. Silver nanocomposites of PS, PMMA, PS-co-PPVTQ, PMMA-co-PPVTQ, PS-co-PAPQ and PMMA-co-PAPQ were synthesized by the addition of silver nitrate into the polymer solution. The reduction of silver ions into silver nanoparticles was performed in DMF and water. Thermogravimetric (TGA) analysis was used to determine the thermal stability of the copolymers and their silver nanocomposites. The X-ray diffraction (XRD) analysis indicated the amorphous structures of the co-polymers and confirmed the formation of silver nanoparticles. The antitumor and antibacterial activities were screened for the copolymers and enhanced by the formation of their silver nanocomposites. In vivo antitumor activity in Ehrlich Ascitic Carcinoma (EAC) mice model showed that PS-co-PPVTQ/Ag NPs, PMMA-co-PPVTQ/Ag NPs, and PMMA-co-PAPQ/Ag NPs displayed promising inhibitory effects against EAC and induce apoptosis against MCF-7 cells.

scholarly journals Limiting Populations and Spread of Clavibacter michiganensis subsp. michiganensis on Seedling Tomatoes in the Greenhouse

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 535-542 ◽  
Author(s):  
N. A. Werner ◽  
D. W. Fulbright ◽  
R. Podolsky ◽  
J. Bell ◽  
M. K. Hausbeck
Keyword(s):  
Bacterial Canker ◽  
Susceptible Cultivar ◽  
Copper Hydroxide ◽  
Clavibacter Michiganensis ◽  
Canker Disease ◽  
Resistant Cultivars ◽  
Tomato Seedlings ◽  
Greenhouse Tomato ◽  
Clavibacter Michiganensis Subsp ◽  
Pathogen Populations

Symptomless greenhouse tomato transplants may harbor high populations of Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker, leading to yield loss in the field. The objective of this study was to determine whether resistant cultivars, acibenzolar-S-methyl, avirulent strains of C. michiganensis subsp. michiganensis, or standard bactericides reduce pathogen populations and spread among greenhouse tomato seedlings. All treatments limited pathogen populations compared with the untreated inoculated susceptible cultivar in 1996 and 1998, but not in 1997. In 1996, copper hydroxide alone or mixed with mancozeb or streptomycin limited pathogen populations relative to acibenzolar-S-methyl, acibenzolar-S-methyl mixed with copper hydroxide, and avirulent strains. Copper hydroxide mixed with streptomycin limited pathogen populations compared with copper hydroxide mixed with mancozeb. Adding copper hydroxide to acibenzolar-S-methyl limited pathogen populations compared with acibenzolar-S-methyl alone. In 1998, treatments did not differ significantly from each other in limiting pathogen populations. The treatments limited spread of the bacterium only in 1997. Copper hydroxide mixed with mancozeb limited spread compared with copper hydroxide mixed with streptomycin. Pathogen spread was also reduced among resistant cultivars compared with the susceptible cultivar treated with streptomycin. In the field, the untreated inoculated susceptible cultivar produced yields that were 61% (1996) and 93% (1997) of those produced by the uninoculated susceptible cultivar. Fruit spotting occurred regardless of treatment. To prevent severe bacterial canker disease in the field, growers should initiate and sustain bactericide applications to tomato transplants while in the greenhouse to suppress pathogen populations. Cultivar resistance and acibenzolar-S-methyl may be helpful in disease management of bacterial canker on tomato.

scholarly journals Green Synthesis of Silver Nanoparticles Using Different Plant Materials and Their Antibacterial Activity

2018 ◽  
Vol 6 (4) ◽  
pp. 294-301
Author(s):  
Dipesh Shahi ◽  
Elisha Bhattarai ◽  
Milan Poudel ◽  
Prarthana Pradhan ◽  
Raja Ram Pradhananga ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Cost Effective ◽  
Antibacterial Activities ◽  
Ag Nps ◽  
Plant Materials ◽  
Green Route ◽  
Sem Study ◽  
Varied Size ◽  
Physical And Chemical

The green route of metal nanoparticles synthesis has received significant attention in recent years due to it's cost-effective, non-toxic and eco-friendly nature in comparison to other physical and chemical methods. This study reports on the synthesis of silver nanoparticles (Ag-NPs) from bio-reduction of 1mM aqueous silver nitrate (AgNO3) by extracts prepared from three different plants namely, Brassica oleracea L. var. italica Plenck (Broccoli), Capsicum annuum L. (Chili) and Parthenium hysterophorus L. (Carrot grass). The synthesized Ag-NPs were characterized using UV- visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Ag-NPs synthesized showed the surface plasmon resonance with the appearance of absorption peaks around the range of 410-430 nm. The possible biomolecules involved in the reduction and the stabilization of synthesized Ag-NPs were found to be alcoholic, phenolic, amine and carbonyl groups. SEM study revealed that Ag-NPs were spherical in shape with varied size about 10-40 nm. Besides, the analysis of antioxidant and antibacterial activities of Ag-NPs was carried out. The Ag-NPs synthesized using B. oleracea extract showed the higher antioxidant activity than Ag-NPs synthesized from both C. annuum & P. hysterophorus extracts. Ag-NPs exhibited good antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The higher antibacterial activity was shown by Ag-NPs synthesized from P. hysterophorus extract in comparison to Ag-NPs synthesized from both C. annuum & B. oleracea extracts. Hence, it can be concluded that Ag-NPs synthesized following the green route could be the source for potential antioxidant and antibacterial agents. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 294-301

scholarly journals Enhancement of the antibacterial potential of plantaricin by incorporation into silver nanoparticles

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sara Adel Amer ◽  
Hala Mohamed Abushady ◽  
Rasha Mohamed Refay ◽  
Mahmoud Ahmed Mailam
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Foodborne Pathogens ◽  
Inhibitory Activity ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Stability Period ◽  
Genes Encoding ◽  
Pharmaceutical Industries ◽  
Antibacterial Potential

Abstract Background Bacteriocins are proteinaceous compounds produced from lactic acid bacteria. Bacteriocins are well-known for their antibacterial potential and safety for application in food. However, the commercial availability of bacteriocin is facing several limitations; among them is the low yield and short stability period. That calls for a new strategy for overcoming these hurdles. Among these approaches is incorporating bacteriocin in nanoparticles. So, the aim of this study was to enhance the plantaricin produced from isolated Lactobacillus plantarum strain using nanotechnology. Results In this study, the plnEF genes encoding plantaricin EF have been identified and sequenced (accession number of MN172264.1). The extracted bacteriocin (EX-PL) was obtained by the ammonium sulfate method. Then, it was used for biosynthesizing plantaricin-incorporated silver nanoparticles (PL-SNPs). The synthesized nanoparticles were confirmed by SEM-EDAX analysis. The antibacterial activity of both combined (PL-SNPs) and extracted plantaricin (EX-PL) were tested against some strains of foodborne pathogenic bacteria. The results revealed that the antibacterial activities were increased by 99.2% on the combination of bacteriocin with the silver nanoparticle. The MIC of EX-PL (7.6 mg/mL) has been lowered after incorporating into silver nanoparticles and reached 0.004 mg/mL for PL-SNPs. Despite that extracted plantaricin showed no inhibitory activity towards Listeria monocytogenes, plantaricin-incorporated silver nanoparticles displayed inhibitory activity against this strain. Furthermore, the stability period at 4 °C was increased from 5 days to 60 days for EX-PL and PL-SNPs, respectively. Conclusions Plantaricin-incorporated silver nanoparticles possess higher antibacterial activity and more stability than the free one, which makes it more fitting for combating foodborne pathogens and open more fields for applications in both food and pharmaceutical industries. Graphical abstract

scholarly journals In vitro Antibacterial Activities of Honey Bee Extracts against Bacterial Isolates of Wound Infections

2021 ◽  
pp. 20-25
Author(s):  
O. A. Ayodele ◽  
J. O. Aribisala ◽  
A. T. Oseni ◽  
M. K. Oladunmoye
Keyword(s):  
Antibacterial Activity ◽  
Honey Bee ◽  
Honey Bees ◽  
Inhibitory Activity ◽  
Ethanolic Extract ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Wound Infections ◽  
Zones Of Inhibition

Microorganisms most especially bacteria, continue to develop resistance against antimicrobial agents; hence novel sources of antibiotics are urgently needed to reduce this problem. This study was carried out to investigate the antibacterial activities of ethanolic, chloroform and aqueous extracts of Apis mellifera (honey bee) on isolates of wound infections. The isolates used in this study were procured from University of Ilorin Teaching Hospital (UITH) and confirmed using morphological and biochemical tests. The isolates used include; Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae, Proteus mirabilis and Proteus vulgaris. Honey bees were collected from an apitherapist at Sunshine honey and agro foods, Akure, Ondo State Nigeria. The whole insect was used for in vitro antibacterial evaluation of the isolates using agar well diffusion method. Ethanolic extract of A. mellifera had the highest inhibitory activity with mean zones of inhibition ranging from 7.40 mm to 21.67 mm, chloroform extracts had moderate inhibitory activity ranging from 4.63 mm to 10.03 mm while the aqueous extract had the least activity with zones of inhibition ranging from 3.00 mm to 6.30 mm. However, no antibacterial activity was observed against P. aeruginosa for all the extracts. It is concluded that extracts of honey bees most especially the ethanolic extract have antibacterial activity and thus could be a potential antibacterial agent against isolates of wound infections.

scholarly journals Bioremoval of PVP coated silver nanoparticles using Aspergillus niger: the role of exopolysaccharides

2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Alrshim ◽  
Anindya Chanda
Keyword(s):  
Silver Nanoparticles ◽  
Aspergillus Niger ◽  
Wastewater Treatment Plants ◽  
Aqueous Media ◽  
Visible Spectrum ◽  
Ag Nps ◽  
Characteristic Peak ◽  
Uv Visible

Abstract The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. PVP-Ag-PVP resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.

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