Inhibition of inter-microbial predation by chlorinated hydrocarbons

Abstract

TIDAL or estuarine regions have traditionally served as sinks for municipal sewage. Some microbial predators in the sea feed on the enteric bacteria contained in such sewage¹. Recently, the concentration of chlorinated hydrocarbons in the sea, especially in estuarine regions, has increased although it remains considerably below the concentration which directly affects the viability of predators or intestional pathogens. But, estuarine chlorinated hydrocarbon concentrations are within a factor of 20 of those which we have observed to inhibit the chemotactic response of marine bacteria². Because bacterial predators are chemotactic specifically to exudates of their prey³, inhibition of chemotaxis by chlorinated hydrocarbons may directly affect estuarine self-purification rates. We report here the impact of two chlorinated hydrocarbons, at concentrations observed to inhibit chemotaxis⁴, on enteric bacteria predation.