title: Assessment of bacterial community structure in nitrifying biofilm under inorganic carbon-sufficient and -limited conditions.
abstract: In this work, nitrification and changes in the composition of the total bacterial community under inorganic carbon (IC)-limited conditions, in a nitrifying moving bed biofilm reactor, was investigated. A culture-independent analysis of cloning and sequencing based on the 16S rRNA gene was applied to quantify the bacterial diversity and to determine bacterial taxonomic assignment. IC concentrations had significant effects on the stability of ammonia-oxidation as indicated by the reduction of the nitrogen conversion rate with high NH4(+)-N loadings. The predominance of Nitrosomonas europaea was maintained in spite of changes in the IC concentration. In contrast, heterotrophic bacterial species contributed to a high bacterial diversity, and to a dynamic shift in the bacterial community structure, under IC-limited conditions. In this study, individual functions of heterotrophic bacteria were estimated based on taxonomic information. Possible key roles of coexisting heterotrophic bacteria are the assimilation of organic compounds of extracellular polymeric substances produced by nitrifiers, and biofilm formation by providing a filamentous structure and aggregation properties.
authors.affiliation: a Center for Water Resource Cycle Research, Korea Institute of Science and Technology (KIST) , Seoul , Republic of Korea.
authors.forename: Hyokwan
authors.initials: H
authors.lastname: Bae
authors.forename: Yun-Chul
authors.initials: YC
authors.lastname: Chung
authors.forename: Heejeong
authors.initials: H
authors.lastname: Yang
authors.forename: Changsoo
authors.initials: C
authors.lastname: Lee
authors.forename: Rio
authors.initials: R
authors.lastname: Aryapratama
authors.forename: Young J
authors.initials: YJ
authors.lastname: Yoo
authors.forename: Seockheon
authors.initials: S
authors.lastname: Lee
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D058448:Biota; D017554:Carbon Compounds, Inorganic / Q000378:metabolism*; D052836:Heterotrophic Processes; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D056910:Republic of Korea; D012722:Sewage / Q000382:microbiology*
chemical_list: D017554:Carbon Compounds, Inorganic; D012722:Sewage; D009584:Nitrogen
keywords: Bacterial community structure; heterotrophs; inorganic carbon; nitrifying biofilm