title: Description of freshwater bacterial assemblages from the upper paraná river floodpulse system, Brazil.
abstract: Bacteria were identified from a large, seasonally flooded river (Paraná River, Brazil) and two floodplain habitats that were part of the same river system yet very different in nature: clearwater Garças Lagoon and the highly humic waters of Patos Lagoon. Bacterioplankton were collected during mid-summer (Jan. 2002) from water samples (2 l) filtered first through a 1.2-microm filter then a 0.2-microm membrane filter representing the particle-attached and free-living sub-communities, respectively. DNA was extracted from filters and purified and a 16S rRNA clone library established for each habitat. Over 300 clones were sequenced and checked for similarity to existing 16S sequences in GenBank using the BLAST algorithm with default parameters. Further classification of clones was done using a species "backbone" attachment followed by parsimony analysis. The majority (85%) of sequences, referred to here as operational taxonomic units (OTUs), were most similar to uncultured bacterium 16S sequences. OTUs from each Proteobacteria sub-phylum (alpha, beta, gamma, delta, epsilon) were present in the Upper Paraná River system, as well as members of the Bacteroidetes. The microbial assemblage from Patos Lagoon was least like other samples in that it had no Firmicutes present and was dominated by Actinobacteria. Verrucomicrobia OTUs were only found in the free-living assemblage. This study documents the presence of globally distributed phyla in Upper Paraná River and taxa unique to habitat and particle attachment.
authors.affiliation: Biology Department, University of Illinois at Springfield, One University Plaza, Springfield, IL, 62703, USA. lemke.michael@uis.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lemke
authors.forename: E Kurt
authors.initials: EK
authors.lastname: Lienau
authors.forename: Jean
authors.initials: J
authors.lastname: Rothe
authors.forename: Thomaz A
authors.initials: TA
authors.lastname: Pagioro
authors.forename: Jeff
authors.initials: J
authors.lastname: Rosenfeld
authors.forename: Rob
authors.initials: R
authors.lastname: Desalle
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D041963:Bacteroidetes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001938:Brazil; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D004190:Disasters; D017753:Ecosystem; D055868:Floods; D014644:Genetic Variation; D019015:Geologic Sediments / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D045483:Rivers / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial