title: Identification of denitrifying bacteria diversity in an activated sludge system by using nitrite reductase genes.
abstract: Nitrite reduction is the key step in the denitrification reaction with two predominant types of nitrite reductase genes: nirS and nirK. The diversity of denitrifying bacteria in a municipal wastewater treatment plant is described by using both these genes. Of the cultured colonies, 22.5% contained the NirS gene and 12.5% the nirK gene. These nitrite reductase-containing colonies could be further divided into five different types by using both restriction fragment length polymorphism and denaturing gradient gel electrophoresis analysis. Phylogenetic analysis showed that these five types of denitrifying bacteria were phylogenetically diverse. Finally, one nirS gene was obtained and compared with the published sequences.
authors.affiliation: Department of Bioenvironmental Engineering, Chung Yuan Christian University, 320, Chungli, Taiwan. sjyou@cycu.edu.tw
authors.forename: Sheng-Jie
authors.initials: SJ
authors.lastname: You
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis*; D004587:Electrophoresis, Agar Gel; D014644:Genetic Variation; D009572:Nitrite Reductases / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012722:Sewage / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012722:Sewage; D009572:Nitrite Reductases