NUCLEIC ACID SEQUENCE AND PLASMID CONTAINING PHAGE RESISTANCE MECHANISM AND BACTERIA IN WHICH THEY ARE PRESENT AND CONFERRING OF PHAGE RESISTANCE MECHANISM

摘要

PURPOSE: To obtain the subject plasmid comprising a phage resistance mechanism and effective in introduction thereof into a lactic acid bacterium important in the dairy industry, conferring the phage resistance thereon and conferring the phage resistance mechanism on other industrially important strains using a phage-resistant lactic acid bacterium. ;CONSTITUTION: A plamid pPF144 of 144 kb is separated from a Lactococcus lactis ssp lactis S45-91-1 strain which is a transconjugant derived from the crossing of a donor strain Lactococcus lactis ssp lactis S91 with a recipient strain Lactococcus ssp lactis S45 derived from a strain Lactococcus lactis ssp lactis C2 and then treated with a restriction enzyme HindIII to isolate a HindIII- HindIII fragment of about 3.3 kb, which is further treated with a restriction enzyme BstBI to isolate a DNA sequence of 1.9 kb which on its own confers the phage resistance. The resultant DNA sequence is joined to a vector and transferred to a lactic acid bacterium to provide a phage-resistant lactic acid bacterium. The prepared lactic acid bacterium is then used to afford the objective plasmid capable of conferring the phage resistance on other strains.;COPYRIGHT: (C)1995,JPO