The occurrence and role of Bdellovibrio bacteriovorus in a polluted river

Bdellovibrio bacteriovorus was found to occur in a polluted river in numbers averaging, over an 18 month period, 10–100 parasites/ml. The parasite was not able to grow at river temperatures on host concentrations below about 10⁶–10⁷ bacteria per ml and even at these had a doubling time of only 24–48 h. The results have indicated that the parasite was not important in reducing the bacterial population of the river studied.