Manfred G. Höfle

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The effects of viral lysis and heterotrophic nanoflagellate (HNF) grazing on bacterial mortality were estimated in a eutrophic lake (Lake Plusssee in northern Germany) which was separated by a steep temperature and oxygen gradient into a warm and oxic epilimnion and a cold and anoxic hypolimnion. Two transmission electron microscopy-based methods(More)
We describe the first freshwater members of the class Actinobacteria that have been isolated. Nine ultramicro-size (<0.1 microm(3)) strains were isolated from five freshwater habitats in Europe and Asia. These habitats represent a broad spectrum of ecosystems, ranging from deep oligotrophic lakes to shallow hypertrophic lakes. Even when the isolated strains(More)
A set of taxonomically unique, blue-coloured bacterial isolates are described on the basis of physiological and biochemical characterization, fatty acid profiling and analyses of 16S rDNA sequences. The flagellated, non-fermentative strains were isolated in 1986, 1987 and 1998 from different layers of the water column of the central Baltic Sea. According to(More)
Lysogeny (bacteria containing inducible prophages) and lytic viral infection (bacteria in a lytic stage of infection) were investigated at the community level in contrasting marine environments such as estuarine versus offshore waters, surface versus deep waters, and oxic versus anoxic waters in the Mediterranean and Baltic Seas. The frequency of lysogenic(More)
The taxonomic relationship between several Shewanella putrefaciens isolates from the Baltic Sea and reference strains of this species is presented in this study. Results from DNA-DNA hybridization using a newly developed non-radioactive detection system and from 16S rRNA gene sequencing demonstrated that S. putrefaciens is a heterogeneous species containing(More)
Two bacterial isolates from the Baltic Sea, BA1 and BA134T, were characterized for their physiological and biochemical features, fatty acid profiles and phylogenetic position based on 16S rRNA gene sequences. The strains were isolated from surface water of the central Baltic Sea during the decay of a plankton bloom. Phylogenetic analysis of their 16S rRNA(More)
High background fluorescence and unspecific staining hampered the epifluorescence enumeration of bacteria in 45% of the tested soil and sediment samples with 4',6-diamidino-2-phenylindole (DAPI) and polycarbonate membrane filters. These problems of the determination of total cell counts can be circumvented by using green fluorescent high-affinity nucleic(More)
A bacterial isolate from the Baltic Sea, BA160(T), was characterized for its physiological and biochemical features, fatty acid profile, G+C content and phylogenetic position based on 16S rRNA gene sequences. The strain was isolated from the surface water of the central Baltic Sea during the decay of a plankton bloom. Phylogenetic analyses of the 16S rRNA(More)
Bacterial community dynamics of a whole drinking water supply system (DWSS) were studied from source to tap. Raw water for this DWSS is provided by two reservoirs with different water characteristics in the Harz mountains of Northern Germany. Samples were taken after different steps of treatment of raw water (i.e., flocculation, sand filtration, and(More)
The bacterial core communities of bulk water and corresponding biofilms of a more than 20-year-old drinking water network were compared using 16S rRNA single-strand confirmation polymorphism (SSCP) fingerprints based on extracted DNA and RNA. The structure and composition of the bacterial core community in the bulk water was highly similar (>70%) across the(More)