Cloning of Phage Resistance Genes from Lactococcus Lactis ssp. cremoris KH

Abstract
A 17.5-kb plasmid conferring restriction and modification-type phage resistance in Lactococcus lactis ssp. cremoris KH was transformed into Lactococcus lactis LM0230 and cloned onto an origin of replication-deficient vector directly into L. lactis. Expression of phage resistance was seen in L. lactis but not in E. coli. A restriction map was generated of the cloned plasmid, and the region encoding phage resistance was localized by insertional inactivation and deletion analysis.