Abundance and diversity of Planctomycetes in a Tyrrhenian coastal system of central Italy
|Author(s)||Pizzetti Ilaria1, 2, Gobet Angelique3, 4, Fuchs Bernhard M.2, Amann Rudolf2, Fazi Stefano1|
|Affiliation(s)||1 : Water Res Inst IRSA CNR, I-00015 Rome, Italy.
2 : Max Planck Inst Marine Microbiol, D-28359 Bremen, Germany.
3 : CNRS, UMR 7144, Stn Biol Roscoff, F-29680 Roscoff, France.
4 : Univ Paris 06, F-29680 Roscoff, France.
|Source||Aquatic Microbial Ecology (0948-3055) (Inter-research), 2011 , Vol. 65 , N. 2 , P. 129-U139|
|WOS© Times Cited||21|
|Keyword(s)||Coastal lake ecology, Planctomycetes, Bacterial diversity, FISH, CARD-FISH, 16S rRNA gene sequencing|
|Abstract||The phylum Planctomycetes is involved in important processes, such as the mineralization of algal biomass and the removal of nitrogen. Using a combination of 16S rRNA sequence analysis and in situ hybridization, we analyzed the diversity and dynamics of Planctomycetes in a shallow meso-eutrophic lake, Lago di Paola, Italy. Planctomycetes detected by the probe PLA46 accounted for 1 to 5% of prokaryotic picoplankton. Abundances were higher in the coastal lake than in the adjacent marine waters. In the surface waters of the lake, the numbers of Planctomycetes fluctuated greatly, reaching a maximum of 1.5 x 10(6) cells ml(-1) in July. The hypoxic bottom waters had less variable cell abundances. The Planctomycetes counts were positively correlated with chlorophyll a concentrations, confirming the role of this phylum in the degradation of algal biomass. We obtained 70 almost full-length 16S rRNA gene sequences of Planctomycetes from 2 libraries. Four distinct clades could be identified. The Pirellula-related group F and the uncultured Planctomycetes group B both had the highest identity with sequences retrieved from marine habitats, whereas the Pirellula-related group E was affiliated with sequences known from freshwater and brackish water environments. The Planctomyces-related group A seems to have a wide habitat range. Catalyzed reported deposition fluorescence in situ hybridization with newly developed probes revealed abundances of the 4 clades in surface and bottom waters ranging from 1 x 10(3) to 5 x 10(4) cells ml(-1). Together, the 4 clade-specific probes identified only about a quarter of the Planctomycetes detected by probe PLA46. This indicates that the diversity of Planctomycetes has not yet been fully explored.|