TY - GEN A1 - Böllmann, Jörg A1 - Engelbrecht, Steffen A1 - Martienssen, Marion T1 - Autofluorescent characteristics of Candidatus Brocadia fulgida and the consequences for FISH and microscopic detection T2 - Systematic and Applied Microbiology N2 - An enrichment culture of Candidatus Brocadia fulgida was identified by three independent methods: analysis of autofluorescence using different microscope filter blocks and a fluorescence spectrometer, fluorescence in situ hybridization (FISH) with anammox-specific probes and partial sequencing of the 16S rDNA, hydrazine synthase hzsA and hydrazine oxidoreductase hzo. The filter block BV-2A (400–440, 470 LP, Nikon) was suitable for preliminary detection of Ca. B. fulgida. An excitation-emission matrix revealed three pairs of excitation-emission maxima: 288–330 nm, 288–478 nm and 417–478 nm. Several autofluorescent cell clusters could not be stained with DAPI or by FISH, suggesting empty but intact cells (ghost cells) or inhibited permeability. Successful staining of autofluorescent cells with the FISH probes Ban162 and Bfu613, even at higher formamide concentrations, suggested insufficient specificity of Ban162. Under certain conditions, Ca. B. fulgida lost its autofluorescence, which reduced the reliability of autofluorescence for identification and detection. Non-fluorescent Ca. Brocadia cells could not be stained with Ban162, but with Bfu613 at higher formamide concentrations, suggesting a dependency between both parameters. The phylogenetic analysis showed only good taxonomical clustering of the 16S rDNA and hzsA. In conclusion, careful consideration of autofluorescent characteristics is recommended when analysing and presenting FISH observations of Ca. B. fulgida to avoid misinterpretations and misidentifications. KW - 16S rDNA KW - Hydrazine synthase hzsA KW - Hydrazine oxidase hzo KW - FISH KW - Candidatus Kuenenia stuttgartiensi KW - Candidatus Brocadia fulgida Y1 - 2018 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/22776 SN - 1618-0984 SN - 0723-2020 VL - 42 IS - 2 SP - 135 EP - 144 ER -