TRANSPOSON-INDUCED MUTAGENESIS IN RHIZOBA CTERIA

Various self-eliminating vectors for transposon-induced mutagenesis in Gram-negative bacteria were evaluated for their ability to induce mut ations in rhizobacterial strains Pseudomonas fluorescens 49 and diazot rophic Pseudomonas sp. 41 8. Apart from auxotrophs, Tn5-induced mutant s of P. fluorescens 49 altered in siderophore synthesis, and mutants o f Pseudomonas sp. 418 defective in nitrogen fixation were obtained and characterized. As a rule, the mutants were found to colonize barley s eedlings roots at the same rate as wild type bacteria.