Actinomycete-flora associated with submersed freshwater macrophytes

Aquatic vegetation from three stream sites located within the US Department of Energy's Savannah River Site, South Carolina was sampled to determine the presence, distribution and diversity of actinomycetes on submersed macrophytes. At individual sampling sites, small pieces of submersed aquatic plants (Sparganium americanum, Ranunculus pusillus and Microanthemum umbrosum) were clipped and placed in sterile sampling containers. In the laboratory, plant fragments were subjected to a wide array of selective measures (5 pretreatments x 8 media X 2 antibiotic regimes x 2 temperatures) in order to obtain the greatest diversity and best isolation methods. A total of 433 actinomycete colonies was isolated, which included 32 distinct strains. The streams, plants and plant tissue types (healthy, necrotic or dead) all had an effect on the presence, distribution and diversity of the actinomycetes. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.