title: Diversity and distribution of a deeply branched novel proteobacterial group found in anaerobic-aerobic activated sludge processes.
abstract: A novel coccobacilli group found previously in enhanced biological phosphorus removal (EBPR) systems was further revealed to have a high degree of diversity and distribution in various activated sludge systems. Phylogenetic analysis based on 14 existing and 18 newly retrieved 16S rRNA sequences revealed that these sequences formed a novel cohesive cluster with seven subgroups in the gamma-Proteobacteria. Fluorescence in situ hybridization with a set of probes designed specifically targeting the novel group at different hierarchical levels showed that the novel group with a coccoid (2-4 micro m) to occasionally long-rod (up to 20 micro m) shape widely distributed and in some cases predominated in sludge samples taken from nine lab- and full-scale EBPR systems (10-50% of total cells) and four conventional activated sludge systems (1-10%). Variation of predominance was also observed among those subgroups in systems showing deteriorated or effective EBPR activity.
authors.affiliation: Department of Civil Engineering, National University of Singapore, Singapore 117576.
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Kong
authors.forename: Say Leong
authors.initials: SL
authors.lastname: Ong
authors.forename: Wun Jun
authors.initials: WJ
authors.lastname: Ng
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D010758:Phosphorus / Q000378:metabolism; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification*; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D010758:Phosphorus