PMID- 12588299
OWN - NLM
STAT- MEDLINE
DCOM- 20030423
LR  - 20191210
IS  - 1462-2912 (Print)
IS  - 1462-2912 (Linking)
VI  - 5
IP  - 3
DP  - 2003 Mar
TI  - Quantification of cell-specific substrate uptake by probe-defined bacteria under 
      in situ conditions by microautoradiography and fluorescence in situ 
      hybridization.
PG  - 202-11
AB  - A technique based on quantitative microautoradiography (QMAR) and fluorescence in 
      situ hybridization (FISH) was developed and evaluated in order to determine the 
      quantitative uptake of specific substrates in probe-defined filamentous bacteria 
      directly in a complex system. The technique, QMAR-FISH, has a resolution of a 
      single cell and is based on an improved fixation protocol and the use of an 
      internal standard of bacteria with known specific radioactivity. The method was 
      used to study the in situ ecophysiology of the filamentous bacteria 'Candidatus 
      Meganema perideroedes' and Thiothrix sp. directly in an activated sludge system. 
      The cellular uptake rate of tritium-labelled substrates revealed an average 
      cell-specific uptake rate of 4.1 yen 10-15 mol of acetate cell-1 h-1 and 3.1 yen 
      10-15 mol of acetate cell-1 h-1 for the two filamentous species respectively. The 
      two filamentous species had very similar activity in all cells along each 
      filament. Surprisingly, the filaments within both probe-defined populations had 
      threefold variation in activity between the different filaments, demonstrating a 
      large variation in activity level within a single population in a complex system. 
      The substrate affinity (Ks) for uptake of acetate of the cells within the two 
      filamentous bacteria was determined by incubation with variable concentrations of 
      labelled acetate. The Ks values of the 'Candidatus Meganema perideroedes' and the 
      Thiothrix filamentous bacteria were determined to be 1.8 micro M and 2.4 micro M 
      acetate respectively.
FAU - Nielsen, Jeppe Lund
AU  - Nielsen JL
AD  - Section of Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, 
      DK-9000 Aalborg, Denmark. jeppe@bio.auc.dk
FAU - Christensen, Dinna
AU  - Christensen D
FAU - Kloppenborg, Marie
AU  - Kloppenborg M
FAU - Nielsen, Per Halkjaer
AU  - Nielsen PH
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Environ Microbiol
JT  - Environmental microbiology
JID - 100883692
RN  - 0 (Acetates)
RN  - 0 (Carbon Radioisotopes)
RN  - 0 (Oligonucleotide Probes)
RN  - 0 (Sewage)
RN  - 10028-17-8 (Tritium)
SB  - IM
MH  - Acetates/*metabolism
MH  - Alphaproteobacteria/*classification/genetics/*metabolism
MH  - Autoradiography
MH  - Carbon Radioisotopes/metabolism
MH  - Gammaproteobacteria/*classification/genetics/*metabolism
MH  - In Situ Hybridization, Fluorescence/*methods
MH  - Microscopy, Confocal
MH  - Oligonucleotide Probes
MH  - Sewage/*microbiology
MH  - Tritium/metabolism
MH  - Waste Disposal, Fluid
EDAT- 2003/02/18 04:00
MHDA- 2003/04/24 05:00
CRDT- 2003/02/18 04:00
PHST- 2003/02/18 04:00 [pubmed]
PHST- 2003/04/24 05:00 [medline]
PHST- 2003/02/18 04:00 [entrez]
AID - 402 [pii]
AID - 10.1046/j.1462-2920.2003.00402.x [doi]
PST - ppublish
SO  - Environ Microbiol. 2003 Mar;5(3):202-11. doi: 10.1046/j.1462-2920.2003.00402.x.