Construction and initial characterization of a luminescent Synechococcus sp. PCC 7942 Fe-dependent bioreporter

FEMS Microbiol Lett. 2002 Apr 9;209(2):215-21. doi: 10.1111/j.1574-6968.2002.tb11134.x.


A Synechococcus sp. PCC 7942 bioreporter strain capable of sensing bioavailable Fe was constructed by fusing the Fe-responsive isiAB promoter to the Vibrio harveyi luxAB genes. Monitoring luxAB-dependent luminescence through the growth curve demonstrated that in Fe-replete media, transcription from the isiAB promoter was induced transiently in the mid-exponential phase of growth. The initiation of transcription was the functional response to a 10-fold depletion of intracellular Fe to approximately 12 amol Fe per cell. Constitutive isiAB-dependent transcription was observed in Fe-depleted growth media. A dose-response relationship of the bioreporter was generated using trace metal-buffered Fraquil medium and was best represented by a sigmoidal curve having a linear component extending between pFe 21.1 (Fe3+=10(-21.1) M) and pFe 20.6 (Fe3+)=10(-20.6) M). Initial field trials conducted using water sampled from Lake Erie demonstrate that the bioreporter can serve as a quantitative tool to assess Fe deficiency in natural freshwater environments.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biosensing Techniques
  • Culture Media / chemistry
  • Cyanobacteria / genetics*
  • Dose-Response Relationship, Drug
  • Fresh Water / chemistry*
  • Genes, Reporter / drug effects
  • Genes, Reporter / genetics*
  • Iron / analysis
  • Iron / pharmacology*
  • Luminescent Proteins / genetics*
  • Promoter Regions, Genetic / genetics


  • Culture Media
  • Luminescent Proteins
  • Iron