PMID- 12216655
OWN - NLM
STAT- MEDLINE
DCOM- 20030129
LR  - 20131121
IS  - 0273-1223 (Print)
IS  - 0273-1223 (Linking)
VI  - 46
IP  - 1-2
DP  - 2002
TI  - Quantification of functional groups in activated sludge by microautoradiography.
PG  - 389-95
AB  - Different functional groups of bacteria in activated sludge from a Danish 
      municipal wastewater treatment plant were investigated and quantified on the 
      basis of their ability to take up acetate under different electron acceptor 
      conditions. The number of bacteria in the different functional groups was 
      quantified by microautoradiography or by fluorescence in situ hybridization 
      (FISH). Uptake of radiolabeled acetate was tested under conditions where oxygen, 
      nitrate, ferric iron, and sulfate served as electron acceptors and under 
      methanogenic conditions. Ammonia-oxidizing bacteria and nitrite-oxidizing 
      bacteria were enumerated by applying oligonucleotide probes (FISH). 80% of the 
      total DAPI count hybridised with a mixture of bacterial probes. Most baceria were 
      able to take up acetate with oxygen or nitrate as electron acceptors (74 and 71% 
      of all DAPI-stained bacteria, respectively). The very similar numbers indicate 
      that the alternating aerobic and anoxic conditions in the wastewater treatment 
      plant investigated favoured the presence of facultative aerobic and denitrifying 
      heterotrophic bacteria. The number of bacteria able to take up acetate under 
      anaerobic conditions was around 8% of the total DAPI count. About half of these 
      were able to take up acetate and store it and were thus probably 
      phosphate-accumulating organisms. The remaining 4% of anaerobic acetate-consuming 
      bacteria were mainly iron reducers. By incubating the sludge samples with 
      specific inhibitors against sulfate reduction and methanogenic activity, it was 
      found that sulfate reducers and methanogenic bacteria constituted approximately 
      1% and less than 0.5% of the total DAPI count, respectively.
FAU - Nielsen, J L
AU  - Nielsen JL
AD  - Department of Environmental Engineering, Aalborg University, Denmark. 
      jeppe@civil.auc.dk
FAU - Nielsen, P H
AU  - Nielsen PH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Water Sci Technol
JT  - Water science and technology : a journal of the International Association on 
      Water Pollution Research
JID - 9879497
RN  - 0 (Acetates)
RN  - 0 (Nitrates)
RN  - 0 (Sewage)
RN  - 0 (Sulfates)
RN  - OP0UW79H66 (Methane)
SB  - IM
MH  - Acetates/analysis
MH  - Autoradiography/*methods
MH  - Bacteria, Anaerobic/*physiology
MH  - In Situ Hybridization, Fluorescence
MH  - Methane/analysis
MH  - Nitrates/analysis
MH  - Oxidation-Reduction
MH  - Population Dynamics
MH  - Sewage/*microbiology
MH  - Sulfates/metabolism
MH  - Waste Disposal, Fluid
EDAT- 2002/09/10 10:00
MHDA- 2003/01/30 04:00
CRDT- 2002/09/10 10:00
PHST- 2002/09/10 10:00 [pubmed]
PHST- 2003/01/30 04:00 [medline]
PHST- 2002/09/10 10:00 [entrez]
PST - ppublish
SO  - Water Sci Technol. 2002;46(1-2):389-95.