Aerobic growth of motile and non-motile bacteria an the surface of solid culture medium in the presence of the heavy metal and ionic salts at two temperatures

Threshold concentrations of heavy metal and ionic salts defining the range of Concentrations, that do not suppress growth, were determined in tryptic soya agar medium. It has been found that the salts of NH4, Mg, Cd and Hg at low concentrations disrupt the symbiotic relationship between the solid surface culture medium and the microorganisms, but do not suppress the growth of the bacteria. These compounds have been included under two different groups as infection inhibitors [Cd and Hg] and as an infection stimulators [NH4, Mg and K]