BACTERIOPLANKTON COMMUNITY COMPOSITION IN A BOREAL FOREST LAKE

The composition of the dominating populations within a bacterioplankto n community was investigated in a mesotrophic, boreal forest lake. Com posite samples were collected monthly throughout the lake for two year s. The community composition was determined by denaturing gradient gel electrophoresis (DGGE) of a polymerase chain reaction (PCR)-amplified part of 16S rDNA, extracted from organisms smaller than 1 mu m. Tempo ral patterns of occurrence in the lake differed among populations. The re was no clear seasonal pattern of variation, but there was a gradual change. The results suggest that variation in the amount of water flo wing into the lake could explain some of the changes in the bacteriopl ankton community. (C) 1998 Federation of European Microbiological Soci eties. Published by Elsevier Science B.V. All rights reserved.