title: Presence and activity of anammox and denitrification process in low ammonium-fed bioreactors.
abstract: A combination of anammox and denitrification process was studied for 300 days in low ammonium-fed bioreactors under the support of organic carbon. Nutrient profiles, (15)N-labelling techniques and qualitative fluorescence in situ hybridization (FISH) probes were used to confirm the nitrogen removal pathways and intercompetition among different bacteria populations. About 80% of nitrogen removal was achieved throughout the study period. The results confirmed that anammox bacteria were absent in the bioreactor inoculated with anaerobic granules only but they were present and active in the central anoxic parts of biopellets in the bioreactor inoculated with mixed microbial consortium from activated sludge and anaerobic granules. It also showed that the anammox bacteria were successfully enriched in the low ammonium-fed bioreactors. Results of this study clearly demonstrated that anammox and denitrification processes could coexist in same environment and anammox bacteria were less competitive than denitrifying bacteria.
authors.affiliation: Department of Ecosocial System Engineering, Kazama Laboratory, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi, 400-8511, Japan. bipinpathak@yahoo.com <bipinpathak@yahoo.com>
authors.forename: Bipin K
authors.initials: BK
authors.lastname: Pathak
authors.forename: Futaba
authors.initials: F
authors.lastname: Kazama
authors.forename: Yuko
authors.initials: Y
authors.lastname: Saiki
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Sumino
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D009587:Nitrogen Isotopes; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D009587:Nitrogen Isotopes; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D002244:Carbon; D009584:Nitrogen