MOLECULAR-GENETIC STUDY OF THE FUNCTIONAL -ROLE OF THE REGULATORY BRPB GENE IN THE PRODUCER OF BIALAPHOS STREPTOMYCES-HYGROSCOPICUS ATCC21705

A chromosomal determinant of Streptomyces hygroscopicus, functioning a s a positive regulator of the bialaphos-resistance gene bar in the mod el strain S. lividans, was conjugatively transferred into a bialaphos (BAP) producer through pVGTB24 plasmid. The plasmid is unable to repli cate autonomously in S. hygroscopicus, but integrates into its chromos ome via homology with the fragment containing this determinant. Integr ation of pVGTB24 was accompanied by a decrease in resistance of S. hyg roscopicus exconjugant clones to the self-produced antibiotic and also by a decrease in their antibiotic productivity.