Fluorescence in situ hybridization (FISH) detection of nitrite reductase transcripts (nirS mRNA) in Pseudomonas stutzeri biofilms relative to a microscale oxygen gradient.
Microsensor measurements of oxygen were combined with mRNA-targeted fluorescence in situ hybridization (FISH) to relate the expression of nitrite reductase (nirS) to oxygen concentrations in artificial biofilms of the denitrifier Pseudomonas stutzeri. A distinct zone of nirS transcript-containing cells was detected at the oxic-anoxic transition zone, below an oxygen threshold concentration of 0.7-2.5μM, depending on incubation conditions. Although not a routine technique yet, the possibility of coupling microsensor and mRNA-targeted FISH analyses described here opens for studies addressing microenvironment, identity, and actual activity of microbes in stratified environments at single cell resolution.
Department of Bioscience, Microbiology, Aarhus University, Ny Munkegade 114, DK-8000 Aarhus C, Denmark.
Michael V W
MV
Kofoed
Daniel Åa
DÅ
Nielsen
Niels Peter
NP
Revsbech
Andreas
A
Schramm
D018441:Biofilms / Q000254:growth & development*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D009572:Nitrite Reductases / Q000235:genetics*; D010100:Oxygen / Q000032:analysis*; D044223:Pseudomonas stutzeri / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics*
D012333:RNA, Messenger; D009572:Nitrite Reductases; D010100:Oxygen