Screening of a novel lactobacilli replicon from plasmids of Lactobacillus reuteri KCTC 3678

A novel lactobacilli replicon from plasmids of Lactobacillus reuteri KCTC 3678 was isolated. Eight L. reuteri strains from Korean Collection for Type Cultures (KCTC) and Korea Food Research Institute (KFRI) were screened for cryptic plasmids and most strains harbored 1 or 2 plasmids. Particularly, L. reuteri KCTC 3678 contained 6 plasmids which all were used for screening of lactobacilli replicon. EcoRI digests of the plasmid DNA prep from L. reuteri KCTC 3678 were ligated with pUC19 and the recombinant DNAs were serially named from pLR1 to pLR7. A cat (chloramphenicol acetyltransferase; Cmr) gene originated from pC194 was introduced into pLR1-7, resulting in pLR1cat-pLR7cat, respectively. The recombinant plasmids were introduced into L. reuteri KCTC 3679, and only transformants harboring pLR5cat were obtained, indicating that the insert in pLR5 functioned as a lactobacilli replicon.