PMID- 15691913
OWN - NLM
STAT- MEDLINE
DCOM- 20050428
LR  - 20191210
IS  - 0099-2240 (Print)
IS  - 1098-5336 (Electronic)
IS  - 0099-2240 (Linking)
VI  - 71
IP  - 2
DP  - 2005 Feb
TI  - Isotope labeling and microautoradiography of active heterotrophic bacteria on the 
      basis of assimilation of 14CO(2).
PG  - 646-55
AB  - Most heterotrophic bacteria assimilate CO(2) in various carboxylation reactions 
      during biosynthesis. In this study, assimilation of (14)CO(2) by heterotrophic 
      bacteria was used for isotope labeling of active microorganisms in pure cultures 
      and environmental samples. Labeled cells were visualized by microautoradiography 
      (MAR) combined with fluorescence in situ hybridization (FISH) to obtain 
      simultaneous information about activity and identity. Cultures of Escherichia 
      coli and Pseudomonas putida assimilated sufficient (14)CO(2) during growth on 
      various organic substrates to obtain positive MAR signals. The MAR signals were 
      comparable with the traditional MAR approach based on uptake of (14)C-labeled 
      organic substrates. Experiments with E. coli showed that (14)CO(2) was 
      assimilated during both fermentation and aerobic and anaerobic respiration. The 
      new MAR approach, HetCO(2)-MAR, was evaluated by targeting metabolic active 
      filamentous bacteria, including "Candidatus Microthrix parvicella" in activated 
      sludge. "Ca. Microthrix parvicella" was able to take up oleic acid under 
      anaerobic conditions, as shown by the traditional MAR approach with [(14)C]oleic 
      acid. However, the new HetCO(2)-MAR approach indicated that "Ca. Microthrix 
      parvicella," did not significantly grow on oleic acid under anaerobic conditions 
      with or without addition of NO(2)(-), whereas the addition of O(2) or NO(3)(-) 
      initiated growth, as indicated by detectable (14)CO(2) assimilation. This is a 
      metabolic feature that has not been described previously for filamentous 
      bacteria. Such information could not have been derived by using the traditional 
      MAR procedure, whereas the new HetCO(2)-MAR approach differentiates better 
      between substrate uptake and substrate metabolism that result in growth. The 
      HetCO(2)-MAR results were supported by stable isotope analysis of (13)C-labeled 
      phospholipid fatty acids from activated sludge incubated under aerobic and 
      anaerobic conditions in the presence of (13)CO(2). In conclusion, the novel 
      HetCO(2)-MAR approach expands the possibility for studies of the ecophysiology of 
      uncultivated microorganisms.
FAU - Hesselsoe, Martin
AU  - Hesselsoe M
AD  - Department of Life Sciences, Aalborg University, Sohngaardsholmsvej 57, DK-9000 
      Aalborg, Denmark.
FAU - Nielsen, Jeppe Lund
AU  - Nielsen JL
FAU - Roslev, Peter
AU  - Roslev P
FAU - Nielsen, Per Halkjaer
AU  - Nielsen PH
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Appl Environ Microbiol
JT  - Applied and environmental microbiology
JID - 7605801
RN  - 0 (Carbon Isotopes)
RN  - 0 (Carbon Radioisotopes)
RN  - 0 (Culture Media)
RN  - 0 (Fatty Acids)
RN  - 0 (Sewage)
RN  - 142M471B3J (Carbon Dioxide)
SB  - IM
MH  - Actinobacteria/cytology/growth & development/metabolism
MH  - Autoradiography/methods
MH  - Bacteria/cytology/growth & development/*metabolism
MH  - Bacteriological Techniques
MH  - Carbon Dioxide/*metabolism
MH  - Carbon Isotopes/metabolism
MH  - Carbon Radioisotopes/metabolism
MH  - Culture Media
MH  - Escherichia coli/growth & development/metabolism
MH  - Fatty Acids/analysis
MH  - Isotope Labeling/*methods
MH  - Pseudomonas putida/growth & development/metabolism
MH  - Sewage/microbiology
PMC - PMC546759
EDAT- 2005/02/05 09:00
MHDA- 2005/04/29 09:00
PMCR- 2005/02/01
CRDT- 2005/02/05 09:00
PHST- 2005/02/05 09:00 [pubmed]
PHST- 2005/04/29 09:00 [medline]
PHST- 2005/02/05 09:00 [entrez]
PHST- 2005/02/01 00:00 [pmc-release]
AID - 71/2/646 [pii]
AID - 1301-04 [pii]
AID - 10.1128/AEM.71.2.646-655.2005 [doi]
PST - ppublish
SO  - Appl Environ Microbiol. 2005 Feb;71(2):646-55. doi: 
      10.1128/AEM.71.2.646-655.2005.