Regulatory Coupling of Nitrogen and Carbon Metabolism in Nitrogen‐FixingPseudomonas stutzeriA1501

The root-associated Pseudomonas stutzeri, strain A1501, is one of the rare examples of a nitrogen-fixing strain within the Pseudomonas genus. In this strain the nitrogen fixation cluster is carried on a 49-kb genomic island. Recent advances on the identification of the regulatory cascades controlling nitrogen fixation and carbon sources utilization in P. stutzeri A1501 is reviewed with a special emphasis on the role of the CbrA-CbrB-CrcZ-Crc regulatory system in the coupling between the carbon and the nitrogen metabolism. Using a deep sequencing approach, a set of small regulatory RNA (ncRNAs) expressed under nitrogen fixation conditions has been identified (including the 407 nt ncNRA crcZ), and their potential role in the control of nitrogen fixation process is discussed.