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The Open Microbiology Journal 2015The 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...
Model-based Characterization of the Parameters of Dissimilatory Sulfate Reduction Under the Effect of Different Initial Density of Desulfovibrio piger Vib-7 Bacterial Cells.
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) hour of cultivation. The increase in the initial concentration of cells to 1 mg/ml led to the beginning of the stationary growth phase in 24th hours of cultivation. Under these conditions, sulfate and lactate were consumed completely in the 48th hour of cultivation. The kinetic analysis of the curves of bacterial growth and the process of dissimilatory sulfate reduction by D. piger Vib-7 was carried out.
PubMed: 26668663
DOI: 10.2174/1874285801509010055 -
Polish Journal of Microbiology 2015Intestinal sulfate-reducing bacteria reduce sulfate ions to hydrogen sulfide causing inflammatory bowel diseases of humans and animals. The bacteria consume lactate as...
Intestinal sulfate-reducing bacteria reduce sulfate ions to hydrogen sulfide causing inflammatory bowel diseases of humans and animals. The bacteria consume lactate as electron donor which is oxidized to acetate via pyruvate in process of the dissimilatory sulfate reduction. Pyruvate-ferredoxin oxidoreductase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. have never been well-characterized and have not been yet studied. In this paper we present for the first time the specific activity of pyruvate-ferredoxin oxidoreductase 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. Microbiological, biochemical, biophysical and statistical methods were used in this work. The optimal temperature (+35°C) and pH 8.5 for enzyme reaction were determined. The spectral analysis of the puri- fied pyruvate-ferredoxin oxidoreductase from the cell-free extracts was demonstrated. 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) and maximum velocity of the pyruvate-ferredoxin oxidoreductase reaction (V ) were defined. Michaelis constants (Km) of the enzyme reaction were calculated for both intestinal bacterial strains. The studies of the kinetic enzyme properties in the intestinal sulfate-reducing bacteria strains in detail can be prospects for clarifying the etiological role of these bacteria in the development of inflammatory bowel diseases.
Topics: Deltaproteobacteria; Desulfovibrio; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Hydrogen-Ion Concentration; Kinetics; Pyruvate Synthase; Temperature
PubMed: 26373169
DOI: No ID Found -
Acta Biochimica Polonica 2015Phosphotransacetylase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. has never...
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. piger Vib-7, 5.97 ± 0.62 mM for Desulfomicrobium sp. Rod-9) were calculated. The studies of the phosphotransacetylase in the process of dissimilatory sulfate reduction and kinetic properties of this enzyme in intestinal sulfate-reducing bacteria, their production of acetate in detail can be perspective for clarification of their etiological role in the development of the humans and animals bowel diseases. These studies might help in predicting the development of diseases of the gastrointestinal tract, by providing further details on the etiology of bowel diseases which are very important for the clinical diagnosis of these disease types.
Topics: Bacteria; Hydrogen-Ion Concentration; Intestines; Kinetics; Oxidation-Reduction; Phosphate Acetyltransferase; Sulfates; Temperature
PubMed: 25781158
DOI: 10.18388/abp.2014_845 -
The Open Microbiology Journal 2014Activity 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...
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 ± 0.24 mM for D. piger Vib-7 as well as 2.68 ± 0.25 and 2.47 ± 0.27 mM for Desulfomicrobium sp. Rod-9, respectively) were calculated. The described results of acetate kinase, an important enzyme in the process of organic compounds oxidation and dissimilatory sulfate reduction would be perspective and useful for clarification of the etiological role of these bacteria in the development of inflammatory bowel diseases in humans and animals.
PubMed: 25598851
DOI: 10.2174/1874285801408010138