Thematic area of your work
"Nanochemistry and Nanobiotechnology"

Effect of nanoparticles on ATPase activity of
Azotobacter vinelandii IMV B-7076

Chobotarov A.Yu., Chuiko N.V., Chobotarova V.V., Kurdish I.K.

Department of Microbiological Processes on Solid Surfaces,
Zabolotny Institute of Microbiology and Virology, NAS of Ukraine,
154 Acad. Zabolotny Str., Kyiv 03143, Ukraine, andreych@ukr.net

About 99 % of microorganisms function in soil in close interaction with solid particles, which results in changes in their physiological and biochemical activity as compared to free forms. It has previously been demonstrated by us that bentonite nanoparticles (up to 100 nm) stimulate the growth of Azotobacter vinelandii ІМВ В-7076. However, the mechanisms of this activity have not been studied sufficiently. One of the enzymes, relevant for the energy metabolism of bacterial cells, is ATPase, since it facilitates the formation of the electrochemical potential difference on the membrane. This enzymatic activity is an efficient indicator of the general physiological and biochemical status of cells.
We have demonstrated that after introducing Ca2+ and Mg2+ ions into the medium with nanoparticles, the level of the ATPase activity of Azotobacter was higher as compared to the addition of Na+ and K+ ions. For instance, the ATPase activity of A. vinelandii was 8.81 µmol ‧ 10-2/min ‧ mg of protein for Mg2+ ions and 8.57 µmol ‧ 10-2/min ‧ mg of protein for Ca2+ ions. However, after the introduction of Na+ and K+ ions to the medium, the level of the ATPase activity of Azotobacter was 7.94 µmol ‧ 10-2/min ‧ mg of protein and 8.10 µmol ‧ 10-2/min ‧ mg of protein.
It was established that after the addition of 0.05 g/l bentonite into Burk’s medium, the ATPase activity of Azotobacter increased by 19.18 % as compared to the control, and in case of introducing 0.5 g/l bentonite – by 28.26 %. This effect is observed owing to the interaction between bacteria and clay mineral nanoparticles and due to positive impact of magnesium and calcium ions, which are in its composition.
Thus, it was shown that one of possible mechanisms in the effect of nanoparticles on the ATPase activity of A. vinelandii is the interaction between these nanoparticles and the cells. Another relevant role in the positive impact of bentonite nanoparticles on the physiological and biochemical activity of A. vinelandii is played by Ca2+ and Mg2+ ions.