Estimation of kinetics of mercury detoxification from low-inoculum batch cultures of Pseudomonas aeruginosa PU21 (Rip64)

The growth rate of Pseudomonas aeruginosa PU21 (Rip64) and the mercury detoxification rate were determined by using low-inoculum batch cultures. In order to attain invariant culture conditions for the determination of growth kinetics in mercury-containing Pseudomonas minimal media (PMM), the initial cell concentrations were adjusted to approx. 100 cells per ml, and the initial mercury concentrations used were less than 2 μg Hg²⁺ per ml. It was found that the specific growth rate decreased as mercury concentration increased. The relationship between specific growth rate and glucose concentration was found to follow Monod kinetics. The mercury detoxification rate was determined for the viable cells and the dying (non-growing) cells.