A synergistic effect of copper and nickel ions on the growth rates of Pseudomonas aeroginosa and Staphylococcus aureus isolates

Abstract EN

Two isolates of bacteria : Pseudomonas aeroginosa and Staphylococcus aureus were exposed to different concentrations ( 25, 50 and 100 ppm) of copper and nickel ions (as single and mixed), and growth rate of these isolates were measured after different exposure periods of (0, 2, 4, 24 and 72) hrs. The results were showed that the effect of ions on the growth rate of these isolates were depending on ion type, concentration of ions in the medium , the nature of medium (solid or liquid), the group of bacteria(Gram+ve or Gram-ve) , and the periods of exposure.

Also, the results were showed a synergistic effect caused by the mixture of the two metals ions on the growth rate of these isolates, and this effect including an elongation in the lag phase, decreasing of colonies numbers and colonies diameter, and dead of bacteria according to the ions concentration in the medium.