The microbial community analysis of a 5-stage BNR process with step feed system

Abstract

The microbial communities of 5-stage BNR activated sludge samples were analyzed using fluorescence in-situ hybridization (FISH) and 16S rDNA characterization. The total cell numbers of each reactor were from 2.36 x 10(9) cells/ml to 2.83 x 10(9) cells/ml. From 56.5% to 62.0% of total DAPI cell counts were hybridized to the most bacterial specific probe EUB 338. Among them, beta-proteobacteria were most dominant in each tank. The number of phosphate accumulating organisms (PAOs) was almost 50% of the total cell number in anoxic-1 tank, and these results indicate that this process has a high content of denitrifying phosphorus accumulating organisms (dPAOs). In contrast with FISH, 16S rDNA analysis showed that dominant groups were the Cytophaga-Flavobacterium group and high G+C% gram-positive bacteria, which were determined as PAOs in anoxic-1 tank. The beta subclass Proteobacteria did not accumulate a large amount of polyphosphate. The overall results indicate that high G+C% gram-positive bacteria and the Cytophaga-Flavobacterium group might play a key role as dPAOs in this process.

Research Advances and Challenges in the Microbiology of Enhanced Biological Phosphorus Removal—A Critical Review

“…Lee et al, 2002;Liu et al, 2001;Mudaly et al, 2000). Actinobacteria also have been reported as the most dominant bacterial group in phosphorus-removing sludge (Christensson et al, 1998;H. W. Lee et al, 2003;T.…”

“…Gemmatimonas aurantiaca, a novel polyphosphate-accumulating isolate, placed in the new phylum Gemmatimonadetes, was retrieved from EBPR laboratory sludge (Zhang et al, 2003). Uncultured organisms belonging to the phylum Bacteroidetes, in the genus Flavobacteria and Cytophaga, have been identified repeatedly in substantial numbers with molecular techniques and DAPI staining in EBPR sludge samples (Dabert, Sialve, Delgenès, Moletta, and Godon, 2001;H. W. Lee, 2003).…”

Enrichment of activated sludge in a sequencing batch reactor for polyhydroxyalkanoate production

“…36 Accession number AF388029). All the mentioned genera have been recovered from activated sludge by various authors (Lee et al 2003;Valle et al 2004). The Cytophaga-Flavobacterium group has been studied in relation to PHA production under anaerobic/aerobic conditions (Liu et al, 2001), while Candidatus Meganema perideroedes has been shown to be present and able to be stored in a aerobic reactor intermittently fed with acetate (Beccari et al, 1998; Levantesi et al, 2004).…”

The microbiology of phosphorus removal in activated sludge processes-the current state of play

“…While some molecular data have suggested that the PAO populations active under anoxic and aerobic conditions might be different (Ahn et al, 2002;Lee et al, 2003), it seems increasingly likely that Accumulibacter are the major PAO populations in both denitrifying and conventional EBPR processes (Zeng et al, 2003;Kong et al, 2004;, emphasizing their metabolic versatility. Yet the story may be more complex than that.…”