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

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.

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Soumen Bhattacharjee

Reactive oxygen species (ROS) are astonishingly versatile molecular species and radicals that are poised at the core of a sophisticated network of signaling pathways of plants and act as core regulator of cell physiology and cellular responses to environment. ROS are continuously generated in plants as an inevitable consequence of redox cascades of aerobic metabolism. In one hand, plants are surfeited with the mechanism to combat reactive oxygen species, in other circumstances, plants appear to purposefully generate (oxidative burst) and exploit ROS or ROS-induced secondary breakdown products for the regulation of almost every aspect of plant biology, from perception of environmental cues to gene expression. The molecular language associated with ROS-mediated signal transduction, leading to modulation in gene expression to be one of the specific early stress response in the acclamatory performance of the plant. They may even act as “second messenger” modulating the activities of specific proteins or expression of genes by changing redox balance of the cell. The network of redox signals orchestrates metabolism for regulating energy production to utilization, interfering with primary signaling agents (hormones) to respond to changing environmental cues at every stage of plant development. The oxidative lipid peroxidation products and the resulting generated products thereof (associated with stress and senescence) also represent “biological signals,” which do not require preceding activation of genes. Unlike ROS-induced expression of genes, these lipid peroxidation products produce nonspecific response to a large variety of environmental stresses. The present review explores the specific and nonspecific signaling language of reactive oxygen species in plant acclamatory defense processes, controlled cell death, and development. Special emphasis is given to ROS and redox-regulated gene expression and the role of redox-sensitive proteins in signal transduction event. It also describes the emerging complexity of apparently contradictory roles that ROS play in cellular physiology to ascertain their position in the life of the plant.


2021 ◽  
Vol 4 (1) ◽  
pp. 7-11
Author(s):  
O. Bilyy ◽  
I. Kotsyumbas ◽  
I. Kushnir ◽  
T. Grechukh ◽  
S. Hnatush ◽  
...  

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.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 293-294
Author(s):  
Murat Baymishev ◽  
Sergey Eremin ◽  
Kirill Plemyashov ◽  
Khamidulla Baymishev ◽  
Igor Konopel’tsev ◽  
...  

Abstract The aim of the study was to determine the etiopathogenesis of reproductive dysfunction in highly productive cows. Studies were conducted on cows of black-motley breed, aged 3–5 lactations, with a live weight of 480–520 kg. Cows were divided into two groups. The first group included 20 cows effective inseminated after the first insemination. The second group included 17 cows that did not fertilize after the first insemination. Blood samples (n = 253) were taken from 4–7; 14–17; 24–34; 35–50; 88–95; 195–210 days of pregnancy; during the beginning of dry period (DP); 1–4 days before calving and on the first day after calving. The content of total serum lipids in pregnant animals was 15.8% higher compared to unfertilized animals. In non-pregnant cows, a decrease in free cholesterol (by 28.65%), especially in its ether-bound fraction (14.91%), indicates a lower synthetic function of the liver, which is confirmed by the low serum levels of vitamins A and E (a difference of 11.3 and 23.65%). The DP was characterized by a significant increase in the products of lipid peroxidation - malondialdehyde by 12–17%, diene and triene conjugates - by 10–15 and 8–15%, respectively, and 1–4 days before calving in cows, which subsequently had a pathological calving, in particular - retention of placenta (5 cows), were characterized by an increased content in the blood plasma of lipid peroxidation products. Thus, the difference in the number of dienes, trienes, and malondialdehyde products was 14.0, 12.0, and 23.5%, compared with animals without obstetric pathology. On the first day after calving, this difference increased even more. Cows with retention of placenta had a significantly higher level of lipid peroxidation products and were characterized by a predominance of oxidized products over the antiradical thiol disulfide and ascorbate systems restored in the antioxidant balance.


Stomatologiya ◽  
2020 ◽  
Vol 99 (4) ◽  
pp. 9
Author(s):  
L.R. Kolesnikova ◽  
M.A. Darenskaya ◽  
A.V. Pogodina ◽  
L.A. Grebenkina ◽  
L.V. Natyaganova ◽  
...  

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