ISSN:
1574-6941
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
We documented permanent presence of heterotrophic filaments in three acidified lakes (pH〈5) in the Bohemian Forest. Due to acidification, crustacean zooplankton were absent in all but one lake. In terms of carbon flow, microorganisms were thus almost exclusive players in the pelagic food webs. Variety of extremely long (〉100 μm) heterotrophic filaments occurred in the lakes. The filaments usually accounted for 〉50% of total heterotrophic microbial biomass in the pelagic zone (medians of the total biomass: 82–108 μg C l−1), except for anoxic bottom layers and for episodic appearance of Daphnia longispina in one lake. Seasonal filament formation was mainly induced and maintained by grazing of mixotrophic flagellates (Dinobryon spp.) on small unicellular bacteria in the absence of cladoceran filtration. The filaments were less active than unicellular suspended bacteria. Fluorescence in situ hybridisation revealed that usually 〈50% of total bacteria were targeted with oligonucleotide probes for Eubacteria.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1016/S0168-6496(03)00201-0
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