ANALYSIS OF NIF AND REGULATORY GENES IN ACETOBACTER-DIAZOTROPHICUS

The focus of our collaborative research program is the identification and characterization of nif and related regulatory genes of Acetobacte r diazotrophicus in order to understand what factors influence nitroge n fixation in this unique diazotroph. To date, the following genes hav e been isolated from genomic libraries and are being analyzed: nifHDK, nifA, nifB, nifV, nifE and ntrBC. In addition, Nif mutants have been constructed by insertional mutagenesis. These mutants are currently be ing used in inoculation experiments of sterile sugarcane plants to det ermine whether nitrogen fixed by A. diazotrophicus is significant for plant nutrition. (C) 1997 Elsevier Science Ltd.