Effect of Calcium Cation on Plating Efficiency of the Sulfate-Reducing Bacterium Desulfovibrio vulgaris

ABSTRACT

The presence of Ca²⁺ (concentration, ca. 0.4 mM) in the growth medium causes cells of Desulfovibrio vulgaris (Hildenborough) to aggregate, leading to a decrease in plating efficiency. When the Ca²⁺ concentration in the medium was reduced 20-fold, cell aggregation did not occur and the plating efficiency increased from an initial value of 34% to a final value of 56%.