title: Phylogenetic and metabolic bacterial diversity of Phragmites australis periphyton communities in two Hungarian soda ponds.
abstract: Bacterial diversity of reed (Phragmites australis) periphyton communities of Kelemen-szék and Nagy-Vadas (two Hungarian soda ponds) was investigated using molecular cloning and cultivation-based techniques. The majority of the 80 Kelemen-szék and 72 Nagy-Vadas bacterial isolates proved to be moderately halophilic and alkaliphilic. A great proportion of the isolates showed phosphatase and urease activity, utilized aesculin, citrate and certain biopolymers (e.g., gelatine and tween 80). Partial 16S rDNA sequence analysis of 33 Kelemen-szék and 20 Nagy-Vadas ARDRA group representatives showed Gram-positive (Nesterenkonia, Cellulomonas, Dietzia, Bacillus and Planococcus) dominance at both sampling sites. Species of the genera Acidovorax, Hydrogenophaga (beta-Proteobacteria) and Flavobacterium, Sphingobacterium (Bacteroidetes) were represented only from Kelemen-szék. Altogether 16 isolates showed low sequence similarity with yet described bacteria and may represent novel taxa. Screening of the 16S rRNA gene libraries of 129 Kelemen-szék and 158 Nagy-Vadas clones resulted in 30 and 28 different ARDRA groups, respectively. Sequence analysis revealed a Gram-negative (Rheinheimera, Aquimonas, Cellvibrio, Flavobacterium and Sphingobacterium) dominated phylogenetic diversity. A high number of the clones were affiliated with uncultured bacterial clones described from diverse environmental samples.
authors.affiliation: Department of Microbiology, Eötvös Loránd University, Pázmány P. sétány 1/C, 1117, Budapest, Hungary. anna.rusznyak@gmail.com
authors.forename: Anna
authors.initials: A
authors.lastname: Rusznyák
authors.forename: Péter
authors.initials: P
authors.lastname: Vladár
authors.forename: Gitta
authors.initials: G
authors.lastname: Szabó
authors.forename: Károly
authors.initials: K
authors.lastname: Márialigeti
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Borsodi
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D006814:Hungary; D010802:Phylogeny; D006109:Poaceae / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D017931:DNA Primers; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S