Relative effects of bacterial and protozoan predators on survival of Escherichia coli in estuarine water samples.

The relative effect of protozoan and bacterial predators on the survival of Escherichia coli in estuarine water samples was examined. Predacious protozoa exerted their major influence on E. coli destruction during the first 2 days of a 10-day-decline period. Inhibition of protozoa after day 2 had little effect on E. coli survival. Bacterial predators also contributed to E. coli destruction but in natural estuarine water samples were maintained at lower levels due to "grazing" by predacious protozoa.