Ivan Kushkevych | Masaryk University (original) (raw)

Papers by Ivan Kushkevych

American Journal of Infectious Diseases and Microbiology, 2014

Inflammatory bowel disease and ulcerative colitis are complex multifactorial diseases of unknown ... more Inflammatory bowel disease and ulcerative colitis are complex multifactorial diseases of unknown etiology. The etiological role of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 in the development of these inflammatory diseases in rats was studied. Applying sulfate-reducing bacteria, ulcerative colitis in the animals was experimentally induced at the fist time. In total 45 animals in three groups were separated and used in this experiment. Animals in the first group received the standard diet containing a special certified feed for rats and were used as a control. The second group received the standard feed and a dose (1 ml per each day) of modified Kravtsov-Sorokin's liquid medium for the initiation of own potential animal intestinal microflora of sulfate-reducing bacteria. The third group of the animals received the standard feed and dose of a suspension with D. piger Vib-7 and Desulfomicrobium sp. Rod-9 (at a ratio of 1 to 1) in the medium. The changes in the colonic microbiota under these conditions were studied. The bacteria belonging to the normal colonic microbiota were associated with the etiology of inflammatory bowel disease and ulcerative colitis. The concentration of sulfide and acetate in feces from different sections of the large intestine of the rats was determined. The level of ulcerations in the second and third groups of sick animals under the specific conditions was demonstrated. The described experimental results could be particularly useful for the study of inflammatory bowel disease and ulcerative colitis and its therapeutic strategy. These data are also indispensable to apply into mechanistic details that will facilitate better preclinical drug/therapy design to target specific components involved in the disease pathogenesis.

The open microbiology journal, 2015

The objective of this study was to design a model of dissimilatory sulfate reduction process usin... more The objective of this study was to design a model of dissimilatory sulfate reduction process using the Verhulst function, with a particular focus on the kinetics of bacterial growth, sulfate and lactate consumption, and accumulation of hydrogen sulfide and acetate. The effect of the initial density (0.12±0.011, 0.25±0.024, 0.5±0.048 and 1.0±0.096 mg cells/ml of medium) of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 on the growth and dissimilatory sulfate reduction was studied. The exponential growth phase of the D. piger Vib-7 was observed for 72 hours of cultivation at the (0.12 and 0.25 mg/ml) initial concentration of bacterial cells. Sulfate and lactate were consumed incompletely during this time. The increase in the initial concentration of cells to 0.5 and 1 mg/ml led to a shortening of the exponential bacterial growth phase and a shift to the stationary phase of the growth. In the case of 0.5 mg/ml seeding, the stationary growth phase was observed in the 36(th) hou...

Neuro endocrinology letters, 2015

The aim of our work was to evaluate effect of selected salicylamides on cell viability of sulfate... more The aim of our work was to evaluate effect of selected salicylamides on cell viability of sulfate-reducing bacterium Desulfovibrio piger Vib-7 isolated from the human large intestine, as well as to assess antimicrobial activity and biological properties of these compounds. Microbiological, biochemical, biophysical methods, and statistical processing of the results were used. An antimicrobial activity and biological properties of salicylamides against intestinal sulfate-reducing bacteria was studied. Primary in vitro screening of the synthesized selected salicylamides was performed against D. piger Vib-7. Adding 0.37-1.10 µmol.L(-1) (N-(4-bromophenyl)-5-chloro-2-hydroxybenzamide, 5-chloro-2-hydroxy-N-[4-(trifluoromethyl)phenyl]benzamide, 5-chloro-N-(3,4-dichlorophenyl)-2-hydroxybenzamide, 5-chloro-2-hydroxy-N-(4-nitrophenyl)benzamide and 4-chloro-N-(3,4-dichlorophenyl)-2-hydroxybenzamide) caused decrease in biomass accumulation by 8-53, 64-66, 49-50, 82-90, 43-46% compared to control...

Journal of Applied Biomedicine, 2016

The aim of this research was to study the dissimilatory sulfate reduction process by various Desu... more The aim of this research was to study the dissimilatory sulfate reduction process by various Desulfovibrio sp. strains of the human intestine, such as bacterial growth, sulfate- and lactate usage, production of sulfide and acetate by the strains, and carry out cluster and correlation analyses of this process. Methods. Microbiology methods of the study for bacterial strains cultivation and photometric methods for determination of bacterial biomass and hydrogen sulfide concentration were used, sulfate ions concentration was determined by turbidymetric method, lactate concentration was carried out by lactate dehydrogenase. Acetate ions accumulation by the strains was determined by titration. Using the experimental data, the methods of statistical analysis have been also used. Results. The various Desulfovibrio sp. strains accumulated different biomass for ten days of cultivation in modified Kravtsov-Sorokin’s medium. The highest biomass (up to 3.89 g/l) was accumulated by Desulfovibrio...

Sepsis

The effect of cadmium sulfate, copper sulfate, zinc sulfate and lead nitrate on growth and light ... more The effect of cadmium sulfate, copper sulfate, zinc sulfate and lead nitrate on growth and light scattering characteristics of sulfurreducing bacteria Desulfuromonas acetoxidans was studied. Concentration changes and relative content of D. acetoxidans cells in various intervals of sizes under the influence of investigated heavy metal salts were observed. The most crucial changes of concentration dependence have been found under the influence of copper sulfate. Addition of 0.5 mM cadmium sulfate caused a decrease of biomass by 64%, lead nitrate – 40%, copper sulfate – 21%, and zinc sulfate – by 15% at the eight day of cell cultivation comparing with control samples. Key words cadmium sulfate • copper sulfate • Desulfuromonas acetoxidans • lead nitrate • light scattering • zinc sulfate Streszczenie W niniejszej pracy zbadano wpływ siarczanu kadmu, siarczanu miedzi, siarczanu cynku i azotanu ołowiu na wzrost i zdolność do rozpraszania światła przez bakterie Desulfuromonas acetoxidans. ...

Systematic position of phototrophic green bacteria and genus description are presented. The place... more Systematic position of phototrophic green bacteria and genus description are presented. The places of their distribution and living conditions are indicated. The specific chemical composition of the green phototrophic bacteria are described (fat acids, bacteriochlorophylls, carotenoids). Here we also highlighted the questions regarding the metabolism of phototrophic green bacteria. Ecological specificity and the role of phototrophic green bacteria in the natural microbiocenosis have been discussed.

Growth of Desulfovibrio piger Vib-7 bacteria of human intestine under the influence of the electr... more Growth of Desulfovibrio piger Vib-7 bacteria of human intestine under the influence of the electron acceptor and donor in different concentrations and the parameters of dissimilatory sulfate reduction have been studied. An increased intensity of the bacterial growth and production of hydrogen sulfide by the D. piger Vib-7 bacteria was studied under influence of high concentrations of sulfate and lactate (17.4 and 35.6 mM, respectively). The largest quantity of hydrogen sulfide (6.06 mM) under influence of 10.5 mM of was detected on the 72 hour of cultivation; while the bacteria D. piger Vib-7 used about 58% of sulfate ion. The largest quantity of acetate (21.1 mM) is detected on the 72 the hour of growth during cultivating the D. piger Vib-7 in the medium containing 53.4 mM of lactate. Based on the obtained experimental data surface models of sulfate reduction parameters by D. piger Vib-7 under the influence of electron acceptor and donor different concentrations were constructed. T...

In this paper we present a cluster analysis of the dissimilatory sulfate reduction parameters by ... more In this paper we present a cluster analysis of the dissimilatory sulfate reduction parameters by the sulfate-reducing bacteria Desulfovibrio sp. and Desulfomicrobium sp. various strains isolated from human intestine. The studied bacterial strains accumulate hydrogen sulfide and acetate in the intestine. These substances are toxic and effect on the intestinal cells metabolism causing various diseases. Clustering of the bacterial growth, the sulfate and lactate usage as well as hydrogen sulfide and acetate accumulation by the Desulfovibrio sp. and Desulfomicrobium sp. various strains has been carried out. The studied strains have formed different clusters by the specific parameters of sulfate reduction. Correlation coefficients (r) between parameters of dissimilatory sulfate reduction by the Desulfovibrio sp. and Desulfomicrobium sp. strains as well as cross-correlation between the parameters have been determined. Inverse (negative) strong correlation between biomass and sulfate (r = ...

We present the morpho-physiological characterization of bacteria extracted from the water basins ... more We present the morpho-physiological characterization of bacteria extracted from the water basins with high levels of sulphur-containing compounds: Desulphovibrio desulphuricans and Thiocapsa purple sulphur photosynthesizing bacteria. Desulphovibrio desulphuricans Ya-1 bacteria effectively reduce sulphates to Н2S, whereas Thiocapsa sp. use it as an electron donor in process of anaerobic photosynthesis.

New strains of sulfate-reducing bacteria were obtained from human intestine. These bacteria are v... more New strains of sulfate-reducing bacteria were obtained from human intestine. These bacteria are vibrio-like (strains SRB Vib-1, SRB Vib-2, SRB Vib-3) and short rod-like (strains SRB Rod-4 and SRB Rod-5) forms. Growth of these strains of bacteria, usage of sulfates by bacteria and their production of hydrogen sulfide were studied. The strains of sulfate-reducing bacteria SRB Vib-1, SRB Vib-2, SRB Vib-3 more intensively accumulate biomass compared with strains SRB Rod-4 і SRB Rod-5. The SRB Vib-1 and SRB Vib-2 strains grow most intensively. Accumulation of bacterial biomass (3.8 g/l) is the highest on the third day of cultivation, and after that a stationary growth phase began. The SRB Vib-3 strain of bacteria accumulates 2.89 gram per liter of biomass on the third day of bacteria cultivation. Maximal biomass of SRB Rod-4 and SRB Rod-5 bacteria strains ranged from 2.59 to 3.25 gram per liter on the eighth day of cultivation. The obtained sulfate-reducing bacteria intensively use sulfa...

Ukrainskii biokhimicheskii zhurnal

Glutathione is the metal stress protector and changes of its level in the sulfate-reducing bacter... more Glutathione is the metal stress protector and changes of its level in the sulfate-reducing bacteria cells under the influence of heavy metal salts have not been studied yet. CdCl2, Pb(NO3)2, CuCl2, and ZnCl2 influence on the total glutathione level in cell-free extracts of sulfate-reducing bacteria Desulfovibrio desulfuricans IMV K-6 was studied. The research has been carried out using Ellman, Lowry methods, statistical processing of the results. It was shown that the glutathione level depends on the heavy metal salts concentration in the medium. The total glutathione level was the highest under the influence of Pb(NO3)2. Other salts were also toxic to bacteria because glutathione level increased in bacterial cells after addition of these salts to the medium. On the basis of the results of our work the range of heavy metal salts influence on D. desulfuricans IMV K-6 cells glutathione level has been formed for the first time: Pb(NO3)2 > CuCl2 > CdCl2 > ZnCl2.

Modern systematics of phototrophic purple bacteria is described. Their distribution and living co... more Modern systematics of phototrophic purple bacteria is described. Their distribution and living conditions based on literature data and original research data are shown. The morphological characteristics , pigments composition and photosynthesis particularies are described. Participation of these bacteria in the natural sulfur cycle, the ways of their hydrogen sulphide usage are shown. The areas of practical application of purple phototrophic bacteria are pointed.

The sulfate-reducing bacteria from the human intestine have been isolated. These bacteria have be... more The sulfate-reducing bacteria from the human intestine have been isolated. These bacteria have been identified as the Desulfovibrio piger by sequence analysis of the 16S rRNA gene. Comparative sequence analysis has shown the identity of DNA sequences which encode for the 16S rRNA gene of the studied sulfate-reducing bacteria strain with similar sequences as those from the GenBank database. The nucleotide sequence of isolated sulfate-reducing bacteria has 99% homology with sequences Desulfovibrio piger ATCC 29098 deposited in the GenBank.

Microbiology Discovery, 2014

The aim and background of the study were to investigate bacterial growth of the Desulfomicrobium ... more The aim and background of the study were to investigate bacterial growth of the Desulfomicrobium sp. strains from human large intestine, and to study the processes usage of sulfate-and lactate, production of sulfide and acetate by the obtained bacteria as well as to carry out cluster and correlation analysis of these processes. Microbiology methods of the study for bacterial strains cultivation and photometric methods for determination of bacterial biomass and hydrogen sulfide concentration were used, sulfate ions concentration was determined by turbidymetric method, lactate concentration was carried out by lactate dehydrogenase. Acetate ions accumulation by the strains was determined by titration. Using the experimental data, the methods of statistical analysis have been also used. The highest biomass (3.34 g/l) has been accumulated by the Desulfomicrobium sp. strain Rod-9 on the sixth day of cultivation, in comparison to the other strains. Studied strains of the Desulfomicrobium sp. actively reduced the sulfate ions and produced hydrogen sulfide. The highest concentration of hydrogen sulfide (3.14 mM) was produced by the SRB Rod-9 strain on the eighth day of cultivation; while, the strain used about 98% of the sulfate compared with its initial concentration. The strains used lactate fully on the sixth day of cultivation and produced acetate. Clustering of the parameters of the bacterial growth, the sulfate and lactate usage as well as hydrogen sulfide and acetate production by the various Desulfomicrobium sp. strains has been carried out. The correlation coefficients between the parameters have been determined.

Acta biochimica Polonica, 2015

Phosphotransacetylase activity and the kinetic properties of the enzyme from intestinal sulfate-r... more Phosphotransacetylase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. has never been well-characterized and has not been studied yet. In this paper, the specific activity of phosphotransacetylase and the kinetic properties of the enzyme in cell-free extracts of both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were presented at the first time. The microbiological, biochemical, biophysical and statistical methods in this work were used. The optimal temperature and pH for enzyme reaction was determined. Analysis of the kinetic properties of the studied enzyme was carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period, τ) and maximum velocity of the phosphotransacetylase reaction (Vmax) were defined. Michaelis constants (Km) of the enzyme reaction (3.36 ± 0.35 mM for D. pi...

Ukrainskiĭ biokhimicheskiĭ zhurnal

The investigation of specific activity of ATP sulfurylase and kinetic properties of the enzyme in... more The investigation of specific activity of ATP sulfurylase and kinetic properties of the enzyme in cell-free extracts of intestinal bacterial strains Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 is presented. The microbiological, biochemical, biophysical and statistical methods were used in the work. The optimal temperature (35°C) and pH 8.0-8.5 for enzyme reaction were determined. An analysis of kinetic properties of ATP sulfurylase has been carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period, τ) and maximum velocity of the ATP sulfurylase reaction (Vmax) have been defined. Michaelis constants (Km(Sulfate), Km(ATP), Km(APS), and Km(Pyrophosphate)) of the enzyme reaction were demonstrated for both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains.

The open microbiology journal, 2014

Activity of acetate kinase in cell-free extracts and individual fractions and the kinetic propert... more Activity of acetate kinase in cell-free extracts and individual fractions and the kinetic properties of the enzyme obtained from the Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were presented at the first time. The highest activity of the enzyme was measured in the cell-free extracts (1.52 ± 0.163 and 0.46 ± 0.044 U × mg-1 protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively) compared to other fractions. The specific activity of acetate kinase in the extracts of both bacterial strains was determined at different temperature and pH. Analysis of the kinetic properties of the purified acetate kinase was carried out. The acetate kinase activity, initial (instantaneous) reaction rate (V0) and maximum rate of the acetate kinase reaction (Vmax) in D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were defined. Michaelis constants (KmAcetyl phosphate and KmADP) of the enzyme reaction (2.54 ± 0.26 and 2.39 ...

Acta Veterinaria Brno, 2015

ABSTRACT The aim of our work was to study Na+/K+-activated Mg2+-dependent ATPase activity in cell... more ABSTRACT The aim of our work was to study Na+/K+-activated Mg2+-dependent ATPase activity in cell-free extracts of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 isolated from the human large intestine, and to carry out the kinetic analysis of the enzyme reaction. The maximum ATPase activity for both bacterial strains at +35 degrees C was determined. The highest activities of the studied enzyme in the cell-free extracts of D. piger Vib-7 at pH 7.0 and Desulfomicrobium sp. Rod-9 at pH 6.5 were measured. Based on experimental data, the analysis of kinetic properties of the ATP-hydrolase reaction by the studied bacteria was carried out. The enzyme activity, initial (instantaneous) reaction rate (V-0) and maximum rate of the ATPase reaction (V-max) was significantly higher in D. piger Vib-7 cells than in Desulfomicrobium sp. Rod-9. Michaelis constants (K-m) of the enzyme reaction for both bacterial strains were determined.

Molecules, 2014

In this study, a series of twenty-two ring-substituted naphthalene-1carboxanilides were prepared ... more In this study, a series of twenty-two ring-substituted naphthalene-1carboxanilides were prepared and characterized. Primary in vitro screening of the synthesized carboxanilides was performed against Mycobacterium avium subsp.