scholarly journals Light-scattering properties of microorganisms Desulfuromonas acetoxidans by influence of silver

2021 ◽  
Vol 4 (1) ◽  
pp. 7-11
Author(s):  
O. Bilyy ◽  
I. Kotsyumbas ◽  
I. Kushnir ◽  
T. Grechukh ◽  
S. Hnatush ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Light Scattering ◽  
Silver Nitrate ◽  
Catalase Activity ◽  
Metal Salt ◽  
Reduced Glutathione ◽  
Bacterial Cells ◽  
Desulfuromonas Acetoxidans ◽  
Concentration Changes ◽  
Fumarate Addition

The article deals with the concentration changes and relative content of bacterial cells of Desulfuromonas acetoxidans in the intervals of sizes 0.2–2.0 µm under the influence of nano silver particles. Correlation between these changes of light-scattering properties of bacterial cells and growth abilities of bacteria Desulfuromonas acetoxidans under inflence of silver nanoparticles and ions has been shown. The purpose of the work was to research the intensity of processes the change of indexes of the antioxidant system the cells of Desulfuromonas acetoxidans at influence of silver nanoparticles and silver nitrate. The influence of various concentrations of silver nanoparticles and silver nitrate on enzymatic activity of catalase and reduced glutathione synthesis by Desulfuromonas аcetoxidans cells under their cultivation with fumarate addition and with absence of sulphur has been determined. Specific catalase activity increased with enhancing of concentration and duration of bacterial cultivation under the addition of this salt. The highest specific catalase activity was determined on the second day of bacterial growth under the influence of all concentration range of investigated metal salt. The reduced glutathione content under silver nitrate and silver nanoparticles exposure varied depending on the cultivation time and metal concentration. The maximum reduced glutathione content has been observed. The result of catalase activity changes  and glutathione content changes of sulfur-reducing D. acetoxidans bacteria cell-free extracts and has been investigated under the influence of different concentrations of Ag nanoparticles during four days of cultivation has been investigated.

scholarly journals The influence of ferric (III) citrate on ATP-hydrolases of Desulfuromonas acetoxidans ІМV В-7384

2013 ◽  
Vol 21 (1) ◽  
pp. 3-8
Author(s):  
O. Maslovska ◽  
S. O. Hnatush
Keyword(s):  
Lipid Peroxidation ◽  
Growth Medium ◽  
Bacterial Growth ◽  
Metal Salt ◽  
Reactive Oxygen ◽  
Transport Processes ◽  
Hydrolase Activity ◽  
Bacterial Cells ◽  
Lipid Peroxidation Products ◽  
Desulfuromonas Acetoxidans

Desulfuromonas acetoxidans obtains energy for growth by the anaerobic oxidation of organic compounds with the carbon dioxide formation. It was found that ferrum and manganese are used as terminal electron acceptors in the processes of anaerobic respiration, such as dissimilative Fe3+- and Mn4+-reduction, carried out by these bacteria (Lovely, 1991). D. acetoxidans ІМV B-7384 can be used as anode biocatalyst in microbial fuel cell with high electron recovery through acetate oxidation to the electric current as a result of electron transfer to the anode or 3d-type transition metals, such as ferrum and manganese, in the process of their reduction. Investigation of biochemical changes of D. acetoxidans ІМV B-7384 under the influence of Fe (III) compounds is important for optimization of the process of bacterial electricity generation. ATP-hydrolase is located in cytoplasmic membrane, and its subunits are exposed to both the cytoplasm and the external environment. Therefore, the changes of that enzyme activity can be used as an indicator of various stress exposure. Presence of ferric iron ions in the bacterial growth medium could catalyze generation of organic reactive oxygen species, such as peroxyl (ROO-) and alkoxyl (RO-) radicals. Lipid peroxidation is one of the main reasons of cell damage and it’s following death under the influence of reactive oxygen metabolites. It is known that lipid peroxidation and membrane transport processes are somehow interrelated, but mechanisms of such interaction are still unidentified. In our previous researche we have shown the influence of ferric (III) citrate on the intensity of lipid peroxidation of D. аcetoxidans ІМV В-7384. Significant increase of the content of lipid peroxidation products (lipid hydroperoxides, conjugated dienes and malondialdehyde) in bacterial cells has been observed under the addition of ferric (III) citrate into the cultural medium. The increase of the concentration of lipid peroxidation products in bacterial cells confirms free radical mechanism of oxidation of polyunsaturated fatty acids. Thus, for fulfiling complete analyses of cell response against oxidative stress it was reasonable to investigate the influence of ferric (III) citrate on specific ATP-hydrolase activity, Na+, K+-ATP-hydrolase activity and Mg2+-ATP-hydrolase activity of D. acetoxidans ІМV В-7384. Bacteria were cultivated in the modified Postgaite C medium during four days under the anaerobic conditions and temperature +27°С with addition from 10 to 20 mM of ferric (III) citrate into the growth medium. Control samples didn’t contain investigated metal salt. Chosen concentrations of metal salt caused inhibition of bacterial growth by 20–50%. Activities of ATP-hydrolases were investigated as described. It was shown, that specific ATP-hydrolase activity of D. acetoxidans ІМV В-7384 is changing in dependance on duration of ferric (III) citrate exposure and concentration of the metal salt. Addition of the ferric (III) citrate in relatively low concentrations (10–12 mM) causes increasing of specific ATP-hydrolase activity of D. acetoxidans IMV B-7384 in comparison with control. Activity of investigated enzymes was inhibited under the increasing of metal salt concentration in bacterial growth medium. Increase of duration of D. acetoxidans IMV B-7384 cultivation causes decrease of ATP-hydrolase activity. Addition of ferric (III) citrate causes simultaneous increasing of Na+, K+-ATP-hydrolase activity and inhibition of Mg2+-ATP-hydrolase activity during four days of bacterial cultivation.

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Trisodium Citrate ◽  
Synthesis And Characterization ◽  
Silver Nanoplates ◽  
Seed Mediated

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.

scholarly journals Exploring electroactive microenvironments in polymer-based nanocomposites to sensitize bacterial cells to low-dose embedded silver nanoparticles

2021 ◽  
Author(s):  
Joana Moreira ◽  
Margarida M. Fernandes ◽  
Estela O. Carvalho ◽  
Ana Nicolau ◽  
Vesna Lazic ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Dose ◽  
Bacterial Cells

Toxicological evaluation of silver nanoparticles and silver nitrate in rats following 28 days of repeated oral exposure

2016 ◽  
Vol 32 (2) ◽  
pp. 609-618 ◽  
Author(s):  
Guangqiu Qin ◽  
Song Tang ◽  
Shibin Li ◽  
Haoliang Lu ◽  
Yanwu Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Oral Exposure ◽  
Toxicological Evaluation

Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

2014 ◽  
Vol 466-467 ◽  
pp. 232-241 ◽  
Author(s):  
Fabianne Ribeiro ◽  
Julián Alberto Gallego-Urrea ◽  
Kerstin Jurkschat ◽  
Alison Crossley ◽  
Martin Hassellöv ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Daphnia Magna ◽  
Danio Rerio ◽  
Pseudokirchneriella Subcapitata ◽  
High Toxicity

scholarly journals The Design, Characterization and Antibacterial Activity of Heat and Silver Crosslinked Poly(Vinyl Alcohol) Hydrogel Forming Dressings Containing Silver Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 96
Author(s):  
John Jackson ◽  
Helen Burt ◽  
Dirk Lange ◽  
In Whang ◽  
Robin Evans ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Silver Nitrate ◽  
Vinyl Alcohol ◽  
Unmet Need ◽  
Chemical Characterization ◽  
Wound Dressings ◽  
Poly Vinyl Alcohol ◽  
Burn Wound

The prompt treatment of burn wounds is essential but can be challenging in remote parts of Africa, where burns from open fires are a constant hazard for children and suitable medical care may be far away. Consequently, there is an unmet need for an economical burn wound dressing with a sustained antimicrobial activity that might be manufactured locally at low cost. This study describes and characterizes the novel preparation of a silver nitrate-loaded/poly(vinyl alcohol) (PVA) film. Using controlled heating cycles, films may be crosslinked with in situ silver nanoparticle production using only a low heat oven and little technical expertise. Our research demonstrated that heat-curing of PVA/silver nitrate films converted the silver to nanoparticles. These films swelled in water to form a robust, wound-compatible hydrogel which exhibited controlled release of the antibacterial silver nanoparticles. An optimal formulation was obtained using 5% (w/w) silver nitrate in PVA membrane films that had been heated at 140 °C for 90 min. Physical and chemical characterization of such films was complemented by in vitro studies that confirmed the effective antibacterial activity of the released silver nanoparticles against both gram positive and negative bacteria. Overall, these findings provide economical and simple methods to manufacture stable, hydrogel forming wound dressings that release antibiotic silver over prolonged periods suitable for emergency use in remote locations.

Controlling the Surface Plasmon Absorption of Silver Nanoparticles via Green Synthesis Using Pennisetum purpureum Leaf Extract

2018 ◽  
Vol 772 ◽  
pp. 73-77
Author(s):  
Ruelson S. Solidum ◽  
Arnold C. Alguno ◽  
Rey Capangpangan
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Surface Plasmon ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Absorption Peak ◽  
Plasmon Absorption ◽  
Surface Plasmon Absorption

We report on the green synthesis of silver nanoparticles utilizing theP.purpureumleaf extract. Controlling the surface plasmon absorption of silver nanoparticles was achieved by regulating the amount of extract concentration and the molarity of silver nitrate solution. The surface plasmon absorption peak is found at around 430nm. The surface plasmon absorption peak have shifted to lower wavelength as the amount of extract is increased, while plasmon absorption peak shifts on a higher wavelength as the concentration of silver nitrate is increased before it stabilized at 430nm. This can be explained in terms of the available nucleation sites promoted by the plant extract as well as the available silver ions present in silver nitrate solution.

scholarly journals Effects of Momordica Charantia Silver Nanoparticles on the expressions of Genes Associated With Lipid Metabolism and Nephrotoxicity in Streptozotocin-Induced Rats

2021 ◽  
Vol 37 (2) ◽  
pp. 126-133
Author(s):  
O.O Elekofehinti ◽  
M.O Akinjiyan
Keyword(s):  
Diabetes Mellitus ◽  
Silver Nanoparticles ◽  
Lipid Metabolism ◽  
Silver Nitrate ◽  
Nitrate Solution ◽  
Diabetic Control ◽  
Untreated Group ◽  
Rt Pcr ◽  
Hmg Coa Reductase ◽  
Coa Reductase

Hyperlipidemia and hyperglycemia have been implicated in diabetes mellitus (DM) leading to complications such as nephropathy. Medicinal plants like Mormodica charantia (MC) have been used in the treatment of DM over the years but little is known about their mechanisms of action. This study used biotechnology tools to investigate and compare the effects of M. charantia silver nanoparticles (MCSNPs) with M. charantia extract on expressions of genes linked with nephrotoxicity, lipid and glucose metabolisms using reverse-transcriptase polymerase chain reaction (RT-PCR) in streptozotocin-induced diabetic rats. The genes investigated include kidney injury molecule-1 (KIM-1), 3-hydroxyl, 3-methyl glutaryl_coA reductase (HMG-CoA reductase), peroxisome proliferator-activated receptor alpha and gamma (PPARα and PPARγ). Synthesis of MCSNPs was done using 1 mM concentration of aqueous silver nitrate solution at ratio 1:9 (v/v). Experimental rats were induced intraperitoneally with streptozotocin (65 mg/kg) and divided into six groups viz: diabetic control; normal control; silver nitrate (10 mg/kg); MCSNPs (50 mg/kg); Metformin (100 mg/kg) and M. charantia fraction (100 mg/kg). Sacrifice was done after 12 days of treatment and RT-PCR was then used to investigate gene expressions in liver and kidney tissues of the rats. The expression of HMG-CoA reductase gene was significantly upregulated (p<0.05) upon treatment with 50 mg/kg MCSNPs relative to the diabetic untreated group. M. charantia extracts and MCSNPs significantly upregulate (p<0.05) the expressions of PPAR-α and PPAR-γ compared to the diabetic control. Also, a significant (p<0.05) down-regulation of KIM-1 mRNA expression was observed in MCSNPs- treated group, relative to the diabetes untreated group. M. charantia silver nanoparticles could be a potent antidiabetic agent due to its potential to modulate genes associated with lipid metabolism and nephrotoxicity. Keywords: Medicinal plant; Diabetes Mellitus; Silver Nanoparticles; nephrotoxicity; gene expression

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