PROCEDURE FOR THE ISOLATION OF NITROGEN FIXING BACTERIAL STRAINS MUTATED IN THE NITROGEN CONTROL OF SYMBIOTIC NODULATION GENES

摘要

For the improvement of the expression of nodulation genes in symbiotic nitrogen fixing bacteria at high ammonia concentrations the gene regulating the expression of nodulation genes of the microorganisms is inactivated, preferably by chemical mutagenesis, by inserting a foreign DNA sequence into the gene (insertion, transposition), by removing the gene or a fragment thereof (deletion), or by transferring the mutated gene into other bacterial strains or species (with conjugative or mobilizable plasmids, transducing phages, or after molecular cloning, with any plasmid or phage vector) and replacing the wild type gene by the homologous region of the mutant gene.