Institut National de la Recherche Agronomique-Laboratoire de Microbiologie des Sols et de Recherche sur la Flore Pathogène, 17, rue Sully, B.V. 1540, 21034 Cedex, Dijon, France. philippo@dijon.inra.fr
In this study, we report the cloning and characterization of denitrifying gene clusters of Pseudomonas fluorescens C7R12 containing the narXLDKGHJI, nirPOQSM, norCB and nosRZDFYL genes. While consensus sequences for Fnr-like protein binding sites were identified in the promoter regions of the nar, nir, nor and nos genes, consensus sequences corresponding to the NarL binding sites were identified only upstream the nar genes. Monitoring by mRNA analysis the expression of the narG, nirS, norB and nosZ structural genes suggests a sequential induction of the denitrification system in P. fluorescens.