Discovery of the novel candidate phylum "Poribacteria" in marine sponges

Author(s)
Lars Fieseler, Matthias Horn, Michael Wagner, Ute Hentschel
Abstract

Marine sponges (Porifera) harbor large amounts of commensal microbial communities within the sponge mesohyl. We employed 16S rRNA gene library construction using specific PCR primers to provide insights into the phylogenetic identity of an abundant sponge-associated bacterium that is morphologically characterized by the presence of a membrane-bound nucleoid. In this study, we report the presence of a previously unrecognized evolutionary lineage branching deeply in the domain Bacteria that is moderately related to the Planctomycetes, Verrucomicrobia, and Chlamydia lines of decent. Because members of this lineage showed <75% 16S rRNA gene sequence similarity to known bacterial phyla, we suggest the status of a new candidate phylum, named "Poribacteria", to acknowledge the affiliation of the new bacterium with sponges. The affiliation of the morphologically conspicuous sponge bacterium with the novel phylogenetic lineage was confirmed by fluorescence in situ hybridization with newly designed probes targeting different sites of the poribacterial 16S rRNA. Consistent with electron microscopic observations of cell compartmentalization, the fluorescence signals appeared in a ring-shaped manner. PCR screening with "Poribacteria"-specific primers gave positive results for several other sponge species, while samples taken from the environment (seawater, sediments, and a filter-feeding tunicate) were PCR negative. In addition to a report for Planctomycetes, this is the second report of cell compartmentalization, a feature that was considered exclusive to the eukaryotic domain, in prokaryotes.

Organisation(s)
External organisation(s)
Julius-Maximilians-Universität Würzburg
Journal
Applied and Environmental Microbiology
Volume
70
Pages
3724-3732
No. of pages
9
ISSN
0099-2240
DOI
https://doi.org/10.1128/AEM.70.6.3724-3732.2004
Publication date
2004
Peer reviewed
Yes
Austrian Fields of Science 2012
1060 Biology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/c5396c8e-ca0e-4995-ab46-870dfdb97943