Enteric bacterial metabolism of stream sediment eluates

Abstract

River bottom sediments, which were washed free of loosely associated chemical nutrients, were further eluted with phosphate buffer. Chemical analyses of the eluates indicated that 0.3 M buffer (pH 7.0) eluted hexose, protein, and ammonia nitrogen in concentrations 4–6 times that found in the free-flowing water. Respiration experiments showed that selected strains of Enterobacteriaceae, including pathogens, had the ability to metabolize these substrates. These studies indicate that bottom sediments can have a high adsorptive capacity and suggest that they can regulate basic nutrient concentration and eutrophication in situ.