Identification and activities in situ of Nitrosospira and Nitrospira spp. as dominant populations in a nitrifying fluidized bed reactor
- Max-Planck-Inst. fuer Marine Mikrobiologie, Bremen (Germany)
- Technische Univ. Muenchen, Munich (Germany). Lehrstuhl fuer Mikrobiologie
Bacterial aggregates from a chemolithoautotrophic, nitrifying fluidized bed reactor were investigated with microsensors and rRNA-based molecular techniques. The microprofiles of O{sub 2}, NH{sub 4}{sup +}, NO{sub 2}{sup {minus}}, and NO{sub 3}{sup {minus}} demonstrated the occurrence of complete nitrification in the outer 125 {micro}m of the aggregates. The ammonia oxidizers were identified as members of the Nitrosospira group by fluorescence in situ hybridization (FISH). No ammonia- or nitrate-oxidizing bacteria of the genus Nitrosomonas or Nitrobacter, respectively, could be detected by FISH. To identify the nitrite oxidizers, a 16S ribosomal DNA clone library was constructed and screened by denaturing gradient gel electrophoresis and selected clones were sequenced. The organisms represented by these sequences formed two phylogenetically distinct clusters affiliated with the nitrite oxidizer Nitrospira moscoviensis. 16S rRNA-targeted oligonucleotide probes were designed for in situ detection of these organisms. FISH analysis showed that the dominant populations of Nitrospira spp. and Nitrosospira spp. formed separate, dense clusters which were in contact with each other and occurred throughout the aggregate. A second, smaller, morphologically and genetically different population of Nitrospira spp. was restricted to the outer nitrifying zones.
- OSTI ID:
- 658986
- Journal Information:
- Applied and Environmental Microbiology, Vol. 64, Issue 9; Other Information: PBD: Sep 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Genome Streamlining, Proteorhodopsin, and Organic Nitrogen Metabolism in Freshwater Nitrifiers
Population ecology of nitrifiers in a stream receiving geothermal inputs of ammonium