INHIBITION OF BACTERIAL ENZYME-ACTIVITY AND LUMINESCENCE BY URBAN RIVER SEDIMENTS

The toxicological and ecological effects of pollutants in urban river sediments were studied. The sediments were chemically or physically fr actionated, using selective extractants to separate the effects of met al and organic contaminants, and subsequently tested for the inhibitio n of bacterial enzyme activity and luminescence. In many cases the enz yme activity of the sediment-dwelling bacteria was inhibited by metals . The variations in inhibition were attributed to differences in sedim ent complexation of, rather than bacterial community tolerance to, met als. Non-polar organic compounds significantly increased the toxicity of urban river sediments, and it is proposed that polyaromatic hydroca rbons from storm-water are an important source of sediment toxicity.