Contribution of bacteria in the mucilage of Microcystis spp. (Cyanobacteria) to benthic and pelagic bacterial production in a hypereutrophic lake

The mucilage of cyanobacteria represents a unique habitat for both water column and sediment bacteria. In Lake Vallentunasjon, Sweden, the pelagic Microcystis-associated bacteria constituted 19-40% of the total bacterial abundance, and their contribution to the total bacterial production was 7-30%. In the sediment, the mucilage bacteria constituted only 1-5% of the total bacterial abundance, but contributed with 8-13% to the total bacterial production during the summer. Microcystis-associated bacteria thus were less active (bacterial production/cell) than ambient water column bacteria, while in the sediments the Microcystis colonies were 'hot spots' with enhanced bacterial activity as compared to other sediment bacteria. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.