Diversity and distribution of a deeply branched novel proteobacterial group found in anaerobic-aerobic activated sludge processes

Environ Microbiol. 2002 Nov;4(11):753-7. doi: 10.1046/j.1462-2920.2002.00357.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Anaerobiosis
  • Phosphorus / metabolism
  • Phylogeny
  • Proteobacteria / classification*
  • Sewage / microbiology*


  • Sewage
  • Phosphorus