title: Sulfur bacteria in wastewater stabilization ponds periodically affected by the 'red-water' phenomenon.
abstract: Several wastewater stabilization ponds (WSP) in Tunisia suffer periodically from the 'red-water' phenomenon due to blooming of purple sulfur bacteria, indicating that sulfur cycle is one of the main element cycles in these ponds. In this study, we investigated the microbial diversity of the El Menzeh WSP and focused in particular on the different functional groups of sulfur bacteria. For this purpose, we used denaturing gradient gel electrophoresis of PCR-amplified fragments of the 16S rRNA gene and of different functional genes involved in microbial sulfur metabolism (dsrB, aprA, and pufM). Analyses of the 16S rRNA revealed a relatively high microbial diversity where Proteobacteria, Chlorobi, Bacteroidetes, and Cyanobacteria constitute the major bacterial groups. The dsrB and aprA gene analysis revealed the presence of deltaproteobacterial sulfate-reducing bacteria (i.e., Desulfobacter and Desulfobulbus), while the analysis of 16S rRNA, aprA, and pufM genes assigned the sulfur-oxidizing bacteria community to the photosynthetic representatives belonging to the Chlorobi (green sulfur bacteria) and the Proteobacteria (purple sulfur and non sulfur bacteria) phyla. These results point on the diversity of the metabolic processes within this wastewater plant and/or the availability of sulfate and diverse electron donors.
authors.affiliation: Water Treatment and Reuse Laboratory, Water Researches and Technologies Centre of Bordj-Cedria, BP. 273, 8020, Soliman, Tunisia. belilaziz@yahoo.com
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Belila
authors.forename: Ben
authors.initials: B
authors.lastname: Abbas
authors.forename: Imed
authors.initials: I
authors.lastname: Fazaa
authors.forename: Neila
authors.initials: N
authors.lastname: Saidi
authors.forename: Mejdi
authors.initials: M
authors.lastname: Snoussi
authors.forename: Abdennaceur
authors.initials: A
authors.lastname: Hassen
authors.forename: Gerard
authors.initials: G
authors.lastname: Muyzer
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D044822:Biodiversity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D054892:Metagenome; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism*; D014416:Tunisia; D062065:Wastewater / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D062065:Wastewater