Activity of Na+/K+-activated Mg2+-dependent ATP-hydrolase in the cell-free extracts of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9

Ivan Kushkevych,Roman Fafula,Tomáš Parák,Milan Bartoš

doi:10.2754/avb201585010003

Ivan Kushkevych, Roman Fafula + Show 2 more

Open Access

https://doi.org/10.2754/avb201585010003

Copy DOI

Abstract

The aim of our work was to study Na+/K+-activated Mg2+-dependent ATPase activity in cell-free extracts of the sulfate-reducing bacteriaDesulfovibrio pigerVib-7 andDesulfomicrobiumsp. 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 ºC was determined. The highest activities of the studied enzyme in the cell-free extracts ofD. pigerVib-7 at pH 7.0 andDesulfomicrobiumsp. 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 (V0) and maximum rate of the ATPase reaction (Vmax) was significantly higher inD. pigerVib-7 cells than inDesulfomicrobiumsp. Rod-9. Michaelis constants (Km) of the enzyme reaction for both bacterial strains were determined.

Highlights

Sulfate-reducing bacteria carry out the dissimilatory sulfate reduction during anaerobic respiration (Barton and Hamilton 2007)
Rod-9 isolated from the human large intestine, and to carry out the kinetic analysis of the enzyme reaction
ATPase activity and the effect of temperature and pH The activity of Na+/K+-ATPase was studied in different fractions (Table 1)

Summary

Introduction

Sulfate-reducing bacteria carry out the dissimilatory sulfate reduction during anaerobic respiration (Barton and Hamilton 2007). The transport of sulfate ions and organic compounds in the cytoplasm of the bacterial cells occurs through active transport using ATP energy (Barton and Hamilton 2007). In this regard, it is very important to study the mechanisms of sulfate ions transport, enzymatic activity and kinetic properties of other ATP-dependent enzymes of sulfatereducing bacteria from human intestine. A comprehensive study of the functioning and role of Na+/K+-pump as a system of energy-dependent transport of different ions in the regulation of the dissimilatory sulfate reduction and accumulation of hydrogen sulfide will enable to form a holistic view on the participation of these systems in maintaining ion homeostasis of the sulfate-reducing bacteria cells.

Objectives

Methods

Results

Conclusion