PHA-accumulating microorganisms in full-scale wastewater treatment plants.
A study was conducted to clarify phylogenetic affiliations of polyhydroxyalkanoate (PHA)-accumulating microorganisms in full-scale activated sludge processes. Activated sludge samples obtained from three full-scale activated sludge processes were aerobically incubated with excess acetate to increase their PHA content. The buoyant density separation method was applied to selectively collect PHA-accumulating cells, which were then analysed by the group-level FISH and the PCR-DGGE-sequencing methods, and possible PHA-accumulating microbial groups were screened. A set of oligonucleotide probes targeting the microbial groups suspected to accumulate PHA was introduced, and seven oligonucleotide probes were newly designed for this purpose. PHA accumulation of probe-positive cells was confirmed by the post-FISH PHA staining method, wherein PHA staining with Nile Blue A (NBA) was applied after FISH. As a result, the following seven bacterial groups were found to have PHA: Dechloromonas, Accumulibacter, Thauera, Zoogloea, Comamonas, Competibacter and a novel cluster in Beta-proteobacteria. Based on the results of the post-FISH PHA staining method, these seven bacterial groups were estimated to account for around four-tenths to two-thirds of total PHA-accumulating microorganisms.
Oshiki
Mamoru
M
Graduate School of Frontier Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, Japan. oshiki@mw.k.u-tokyo.ac.jp
Onuki
Motoharu
M
Satoh
Hiroyasu
H
Mino
Takashi
T
D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D010802:Phylogeny; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology
D017931:DNA Primers; D004269:DNA, Bacterial; D054813:Polyhydroxyalkanoates; D012722:Sewage