PLASMID p74 DETERMINING MICROCINE SYNTHESIS, AND STRAIN OF BACTERIUM ESCHERICHIA COLI SHOWING ANTIBACTERIAL ACTIVITY Russian patent published in 1995 - IPC

FIELD: microbiology. SUBSTANCE: plasmid p74¹ (molecular mass is 30 mDa) is nonconjugative, its content in cells of strain E. coli C600 is 1-2 copies per a cell, it determines resistance for kanamycin (200 mcg/ml), synthesis of microcine and resistance to the latter. It does not correspond to wide-spread plasmid incompatibility. In cells of strains E. coli plasmid is sustained stably under nonselective conditions for at least 100 generations, it does not act on the growth rate and morphology of cells E. coli. At transformation of DNA of plasmid p74¹ in E. coli cells number of tranformants is 10² per 1 mcg DNA. Using plasmid p74¹ strain E. coli M17 BKM CR-322D is obtained which is harmless for newborn calves, it is adapted in intestine of newborn calves, prevents disease of calves with coli-bacteriosis, enhances viability of sick animals. EFFECT: increased effectiveness of plasmid indicated above. 3 cl, 2 tbl