Effect of NaCl Concentration on the Interaction between Bdellovibrio bacteriovorus HD100 and the E. coli T4 Phage

The effect of NaCl concentration on infection and coinfection of Escherichia coli B with the predatory bacterium Bdellovibrio bacteriovorus HD100 and the T4 phage was studied. The greatest lytic effect of combined application of the phage and the predatory bacterium was exhibited during coinfection in the NaCl-free medium after 24 h of cultivation (a five-order-of-magnitude decrease in the E. coli B titer). Coinfection was less effective (a four-order-of-magnitude decrease in E. coli numbers) at the physiological NaCl concentration (155 mM) after 24 h of interaction. Furthermore, the greatest lytic effect under these conditions was associated with the T4 phage development.