title: Monitoring a widespread bacterial group: in situ detection of planctomycetes with 16S rRNA-targeted probes.
abstract: The group of planctomycetes represents a separate line of descent within the domain Bacteria. Two phylum-specific 16S rRNA-targeted oligonucleotide probes for planctomycetes have been designed, optimized for in situ hybridization and used in different habitats to detect members of the group in situ. The probes, named PLA46 and PLA886, are targeting all or nearly all members of the planctomycete line of descent. Planctomycetes could be detected in almost all samples examined, e.g. a brackish water lagoon, activated sludge, and other wastewater habitats. In situ probing revealed quite uniform morphology and spatial arrangement of the detected cells but profound differences in abundance ranging from less than 0.1% to several percentage of the total cells. Single coccoid cells with diameters between 1 and 2.5 microm were dominating in most samples with the exception of the lagoon, in which rosettes of pear-shaped cells were abundant. The planctomycetes showed generally no hybridization signals with the bacterial probe EUB338, which is in accordance with base changes in their 165 rRNA sequences. A discrete ultrastructure of planctomycete cells was suggested by double staining with rRNA-targeted probes and the DNA-binding dye 4',6-diamidino-2-phenylindole (DAPI). The probe-conferred fluorescence was distributed in a ring-shaped manner around a central DAPI spot. The two probes developed extend the existing set of group-specific rRNA-targeted probes and help to elucidate the basic composition of bacterial communities in a first step of differential analysis. In situ hybridization of environmental samples indicated widespread presence of planctomycetes in different ecosystems.
authors.affiliation: Lehrstuhl fr MikrobiologieTechnische University Arcisstr. 16, D-80290 Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Neef
authors.affiliation: Max-Planck-Institut fr Marine Mikrobiologie, Celsiusstr. 1, D-28359 BremenGermany.|Lehrstuhl fr MikrobiologieTechnische University Arcisstr. 16, D-80290 Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Amann
authors.affiliation: Institut fr Allgemeine Mikrobiologie Christian-Albrechts-Universitt Kiel Am Botanischen Garten 19, D-24118 Kiel Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Schlesner
authors.affiliation: Lehrstuhl fr MikrobiologieTechnische University Arcisstr. 16, D-80290 Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Schleifer
mesh_terms: D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis; D018390:Gene Targeting; D006089:Gram-Negative Anaerobic Bacteria / Q000145:classification / Q000302:isolation & purification*; D017404:In Situ Hybridization, Fluorescence; D012336:RNA, Ribosomal, 16S / Q000235:genetics*
chemical_list: D015342:DNA Probes; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S