Bam HI "c" fragment was identified to be a regulatory region in the genome Of DNA phage 11 Of the strain Rhiaobium meliloti 41. This region was isolated and prepared to be inser·ted in the E. coli plasmid pUCI8, which is isolated and purified from t~ strain E. co i« K 12 IN 109. The endonuclease Bam HJ was ap p l i ed" fo;;---Qpening the circular plasmid and the T4 ligase was used for inserting the Rhiaobiophage fragment. The construction Of the recombinant plasmids were confirmed using gel electrophoresis analysis.